kottke.org posts about science
Riffing on a question Richard Feynman once posed to himself, Tom Chivers asked 12 scientists:
If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generation of creatures, what statement would contain the most information in the fewest words?
I liked the pragmatic answer by Lewis Dartnell, author of The Knowledge: How to Rebuild Civilization in the Aftermath of a Cataclysm
While Feynman's sentence is all good and true, it isn't particularly useful in an immediate pragmatic sense. I wrote a book recently which was intended as a guidebook for rebooting civilisation after an apocalypse, looking at the key technologies and central scientific principles that underpin our lives - the behind-the-scenes fundamentals that we all just take for granted today - and what enabled society to progress through the centuries of history. I argue how the greatest invention of history is the scientific method itself - the knowledge-generation machinery that we have been using for over 350 years now to come to understand how the world works. So if you could preserve only one single sentence, I would push for: 'The natural world is not governed by whimsical gods, but is essentially mechanical and can therefore be understood and then predicted by people, using careful observation, experimentation, and measurement, and importantly by testing your explanations to try to refute them.' It's this reiterative process of refinement that sets science apart from any other system for explaining how the world works.
There are other tips that could help with immediate survival. Diarrhoeal disease kills millions of people every year - all preventable by simple means. One method recommended by the World Health Organisation in developing nations for low-tech treatment of drinking water is called SODIS, or solar disinfection. All you need to do is pour your suspect water into a plastic bottle and leave it in the sun. Ultraviolet rays in sunlight pass straight through and kill any germs. So you can come back to your bottle a day or two later and know that the water you put to your lips isn't going to kill you.
Up until very recently, humans were thought to be the only animals who made and used stone tools, an era in human development that began roughly 3.3 million years ago. But according to this piece at the BBC, some chimpanzees and monkeys in various places around the globe have been using primitive stone tools for hundreds or even thousands of years.
Boesch and his colleagues had previously studied modern chimpanzee stone tool culture in the region. This research revealed that the chimpanzees have an idiosyncratic way of choosing and using their tools.
For instance, chimpanzees will often deliberately opt for particularly large and heavy stone hammers, between 1kg and 9kg, while humans prefer to use stones that weigh 1kg or less. Many of the 4300-year-old stone tools weighed more than 1kg, suggesting they were used by chimpanzees.
Chimpanzees also use their stone tools to crack open certain types of nuts that humans don't eat. Starch residues on some of the ancient tools came from these nuts.
Together, these findings led to an obvious conclusion: chimpanzees have been using stone tools in the rainforests of Ivory Coast for at least 4300 years.
Bjorn Jonsson used the photos taken by NASA's New Horizons spacecraft to make an animation of the probe's flyby of Pluto.
The time covered is 09:35 to 13:35 (closest approach occurred near 11:50). Pluto's atmosphere is included and should be fairly realistic from about 10 seconds into the animation and to the end. Earlier it is largely just guesswork that can be improved in the future once all data has been downlinked from the spacecraft. Light from Pluto's satellite Charon illuminates Pluto's night side but is exaggerated here, in reality it would be only barely visible or not visible at all.
Fantastic...and Pluto's moons flying about in the background is the cherry on the top. (via @BadAstronomer)
In A Children's Picture-book Introduction to Quantum Field Theory, Brian Skinner explains quantum field theory -- "the deepest and most intimidating set of ideas in graduate-level theoretical physics" -- as if you and I are five-year-old children.
The first step in creating a picture of a field is deciding how to imagine what the field is made of. Keep in mind, of course, that the following picture is mostly just an artistic device. The real fundamental fields of nature aren't really made of physical things (as far as we can tell); physical things are made of them. But, as is common in science, the analogy is surprisingly instructive.
So let's imagine, to start with, a ball at the end of a spring.
How massive are they? The Sun is 1 solar mass and as wide as 109 Earths. Sagittarius A, the black hole at the center of the Milky Way, weighs 4.3 million solar masses and is as wide as Mercury is far from the Sun. The black hole at the center of the Phoenix Cluster is one of the largest known black holes in the Universe; it's 73 billion miles across, which is 19 times larger than our entire solar system (from the Sun to Pluto). As for how much it weighs, check this out:
I also like that if you made the Earth into a black hole, it would be the size of a peanut. (thx, reidar)
Emily Lakdawalla provides an update on all of the exploration that's going on in our solar system this month. Here's a quick map view of the 20+ spacecraft exploring our solar system beyond Earth:
Mars remains the most active spot beyond Earth in the solar system. This week, Mars Reconnaissance Orbiter reaches its 10th anniversary of service in space, but it's far from the oldest spacecraft in orbit at Mars; Mars Express and Mars Odyssey are still at work up there. Mars Orbiter Mission has ventured into an extended mission and is still returning photos, though apparently none of the full-disk images in a variety of phases that I had hoped for from its 4-Megapixel color camera. Even Mars' newest resident, MAVEN, is three-quarters of the way through its one-year primary science mission, which began on November 16, 2014. MAVEN's mission will undoubtedly be extended long beyond that, as it will be needed to support surface missions if and when Odyssey and Mars Reconnaissance Orbiter eventually fail.
Both Opportunity and Curiosity have been very active lately. Opportunity has finally reached Marathon Valley, a site identified from orbit to have signs of clay chemistry. The team is excited about the science prospects even though the rover's memory problems persist.
Artist Sam Van Aken is using grafting to create trees that bear 40 different kinds of fruit. National Geographic recently featured Van Aken's Tree of 40 Fruit project:
The grafting process involves slicing a bit of a branch with a bud from a tree of one of the varieties and inserting it into a slit in a branch on the "working tree," then wrapping the wound with tape until it heals and the bud starts to grow into a new branch. Over several years he adds slices of branches from other varieties to the working tree. In the spring the "Tree of 40 Fruit" has blossoms in many hues of pink and purple, and in the summer it begins to bear the fruits in sequence -- Van Aken says it's both a work of art and a time line of the varieties' blossoming and fruiting. He's created more than a dozen of the trees that have been planted at sites such as museums around the U.S., which he sees as a way to spread diversity on a small scale.
No hunger. No pollution. No disease. Wired's Amy Maxmen welcomes you to the age of copy and paste DNA editing and the end of life as we know it.
Genome editing started with just a few big labs putting in lots of effort, trying something 1,000 times for one or two successes. Now it's something that someone with a BS and a couple thousand dollars' worth of equipment can do. What was impractical is now almost everyday. That's a big deal.
[I recently listened to Radiolab's show on Crispr. Recommended. -jkottke]
A company called Oxitec has genetically modified mosquito eggs so that the mosquitos born from them pass along a gene to their offspring that prohibits the mosquitos from reaching sexual maturity and mating. They release the mosquitos into the wild, they mate with the local population of mosquitos, and those born from those matings will die before mating themselves. Voila! Pest control.
Oxitec has conducted trials with its modified mosquito in dengue-ridden regions of Panama, Brazil, Malaysia, and the Cayman Islands. The results show population suppression rates above 90 percent-far greater than the typical 30 percent achieved with insecticides.
The company is currently planning a trial in Florida using this technique to curb an influx of mosquito-borne illness.
This morning, the New Horizons probe zinged safely1 past Pluto. Before it did, it transmitted the best photo we've seen of Pluto so far...the last one we'll get before we get the really good stuff. Look at this:
The probe's "I'm OK!" message will reach Earth around 9pm ET tonight and we'll start seeing photos from the flyby Wednesday afternoon...there's a NASA press conference scheduled for 3pm ET on July 15. So exciting!
Update: The photo above is also the best full-disk image of Pluto that we will get...the rest will be close-ups and such. So that's the official Pluto portrait from now on, folks.
CERN's LHC (Large Hadron Collider) has discovered a new subatomic particle, the pentaquark.
"The pentaquark is not just any new particle," said LHCb spokesperson Guy Wilkinson. "It represents a way to aggregate quarks, namely the fundamental constituents of ordinary protons and neutrons, in a pattern that has never been observed before in over fifty years of experimental searches. Studying its properties may allow us to understand better how ordinary matter, the protons and neutrons from which we're all made, is constituted."
Here's the paper, with more than 680 authors. Between New Horizons zipping past Pluto earlier today (look at this pic!) and this, what a day for science.
Psychologists Dacher Keltner and Paul Ekman served as scientific consultants during the production of Pixar's Inside Out. Keltner studies the origins of human emotion and Ekman pioneered research of microexpressions. In this NY Times piece, they discuss the science behind the movie.
Those quibbles aside, however, the movie's portrayal of sadness successfully dramatizes two central insights from the science of emotion.
First, emotions organize -- rather than disrupt -- rational thinking. Traditionally, in the history of Western thought, the prevailing view has been that emotions are enemies of rationality and disruptive of cooperative social relations.
Second, emotions organize -- rather than disrupt -- our social lives. Studies have found, for example, that emotions structure (not just color) such disparate social interactions as attachment between parents and children, sibling conflicts, flirtations between young courters and negotiations between rivals.
I've thought about Inside Out every day since I saw it. Pixar clearly did their homework on the emotional stuff and it paid off.
As the New Horizons probe nears Pluto, I've been reading a bit more about how it's going to work and what sort of photos we're going to get. Emily Lakdawalla has a comprehensive post about what to expect when you're expecting a flyby of Pluto. The post contains an image of approximations of the photos New Horizon will take, using Voyager images of Jovian and Saturnian moons as stand-ins. The highest resolution photo of Pluto will be 0.4 km/pixel...it'll have this approximate level of detail:
Which is pretty amazing and exciting considering that before the mission started this was our best view of Pluto:
NASA's Eyes app lets you see a simulation of the probe as it approaches Pluto, but if you don't want to download anything, you can watch this video of the flyby instead:
I had no idea the probe spun around so much as it grabs photos & scans and then beams them back to Earth. And the flyby is so fast! New Horizons is currently moving at 32,500 mph relative to the Sun...it's travelling just over 9 miles every second. (via @Tim_Meyer_ & @badastronomer)
Pluto is so far away that we haven't even been able to get a good look at it, not even with the crazy-powerful Hubble telescope. But with NASA's New Horizons mission closing in on our solar system' ninth planet,1 we are getting a better and better view of Pluto every day.1Here's the latest, from just a few hours ago:
New Horizons will reach its closest approach to Pluto in just under 6 days, on July 14. The probe will pass within 7,800 miles of the surface...I can't wait to find out what that day's photos look like.
Update: You don't even need to wait until tomorrow for that better image...here's one that NASA released just a short while ago. Tune in tomorrow for an even better view.
Unlike the Earth, Mars and the Moon don't have strong directional magnetic fields, which means traditional compasses don't work. So how did the Apollo rovers and current Mars rovers navigate their way around? By using manually set directional gyroscope and wheel odometers.
While current un-crewed rovers don't have to return to the comfort of a lunar module, some aspects of the Apollo systems live on in their design. Four U.S. Martian rovers have used wheel odometers that account for slippage to calculate distance traveled. They've also employed gyroscopes (in the form of an inertial measurement units) to determine heading and pitch/roll information.
One of the fun things about reading The Martian is you get to learn a little bit about this sort of thing. Here's a passage about navigation on Mars where astronaut Mark Watney is trying to get to a landmark several days' drive away.
Navigation is tricky.
The Hab's nav beacon only reaches 40 kilometers, so it's useless to me out here. I knew that'd be an issue when I was planning this little road trip, so I came up with a brilliant plan that didn't work.
The computer has detailed maps, so I figured I could navigate by landmarks. I was wrong. Turns out you can't navigate by landmarks if you can't find any god damned landmarks.
Our landing site is at the delta of a long-gone river . NASA chose it because if there are any microscopic fossils to be had, it's a good place to look. Also, the water would have dragged rock and soil samples from thousands of kilometers away. With some digging, we could get a broad geological history.
That's great for science, but it means the Hab's in a featureless wasteland.
I considered making a compass. The rover has plenty of electricity, and the med kit has a needle. Only one problem: Mars doesn't have a magnetic field.
So I navigate by Phobos. It whips around Mars so fast it actually rises and sets twice a day, running west to east. It isn't the most accurate system, but it works.
I wonder why the rovers in the story weren't outfitted with directional gyroscopes and wheel odometers? (See also the operations manual for the lunar rovers.) (via @JaredCrookston)
Here's something that I knew as a kid but had forgotten about: if you get a bike going on its own at sufficient speed, it will essentially ride itself. MinutePhysics investigates why that happens.
Interesting that the bike seems to do much of the work of staying upright when it seems like the rider is the thing that makes it work. (via devour)
While reading this otherwise excellent article written by US soccer player Christie Rampone, I discovered a type of diet I'd never heard of before, the blood type diet (italics mine).
Age and parenting make me think about longevity. I definitely believe one big reason for my longevity has to do with the dietary and fitness changes I made after being diagnosed with auto-immune conditions after giving birth to my youngest daughter Reece in 2011. For example, I've gone gluten-free and have started to eat to my blood-type. Also, a friend introduced me to a natural ingredient called EpiCor to help strengthen my immune system. I have taken EpiCor daily for the past three years and it has become a beneficial part of my daily routine of rest, recovery, working out, eating healthy, and being in airports and hotels more than my own house.
From Wikipedia, an overview of the diet:
The underlying theory of blood type diets is that people with different blood types digest lectins differently, and that if people eat food that is not compatible with their blood type, they will experience many health problems. On the other hand, if a person eats food that is compatible, they will be healthier.
That theory is, in turn, based on an assumption that each blood type represents a different evolutionary heritage. "Based on the 'Blood-Type' diet theory, group O is considered the ancestral blood group in humans so their optimal diet should resemble the high animal protein diets typical of the hunter-gatherer era. In contrast, those with group A should thrive on a vegetarian diet as this blood group was believed to have evolved when humans settled down into agrarian societies. Following the same rationale, individuals with blood group B are considered to benefit from consumption of dairy products because this blood group was believed to originate in nomadic tribes. Finally, individuals with an AB blood group are believed to benefit from a diet that is intermediate to those proposed for group A and group B."
As you might have already guessed, there is no evidence that eating your blood type is beneficial nor do the claims of differing lectin digestion have scientific merit. Homeopathic nonsense.
Tasha Sturm, a lab technician at Cabrillo College, had her 8-year-old son put his handprint on a prepared petri dish and then incubated it for several days. This was the result:
If you'll excuse me, I have to go wash my hands about 4,000 times. Bacteria is cooooool though:
Because of climate change and other activities caused by humans (invasive species, habitat loss), hybridization of species is resulting in things like super-sized coyotes, pizzly bears (grizzly/polar bear hybrids), and other animals that may not be ideally suited to survive.
Some scientists and conservationists see the coywolf as a nightmare of the Anthropocene -- a poster child of mongrelization as plants and animals reshuffle in response to habitat loss, climate change and invasive species. Golden-winged warblers increasingly cross with blue-winged warblers in the U.S. Northeast and eastern Canada. Southern flying squirrels hybridize with northern flying squirrels as the southern species presses northward in Ontario. Polar bears mate with grizzlies in the Canadian Arctic along the Beaufort Sea to produce "pizzly bears."
All of this interbreeding upsets the conventional notion of species as discrete, inviolable entities. Moreover, some scientists and conservationists warn that hybridization will degrade biodiversity as unusual species are lost to genetic homogenization.
Partly scientists fear hybrids will be less fit than organisms that have evolved in place over eons. And often that is true, but the problem solves itself over time as hybrids lose out in the competitive race for survival.
University of Minnesota student Daniel Crawford and geography professor Scott St. George have collaborated on a piece of music called Planetary Bands, Warming World. Composed for a string quartet, the piece uses climate change data to determine the musical notes -- the pitch of each note is tuned to the average annual temperature, which means as the piece goes on, the musical notes get higher and higher.
Researchers using the Keck Observatory have discovered a new kind of galaxy that are large but filled with relatively few stars.
"If the Milky Way is a sea of stars, then these newly discovered galaxies are like wisps of clouds", said van Dokkum. "We are beginning to form some ideas about how they were born and it's remarkable they have survived at all. They are found in a dense, violent region of space filled with dark matter and galaxies whizzing around, so we think they must be cloaked in their own invisible dark matter 'shields' that are protecting them from this intergalactic assault."
The night sky in such galaxies would look a lot like our skies do in large cities:
"If there are any aliens living on a planet in an ultra-diffuse galaxy, they would have no band of light across the sky, like our own Milky Way, to tell them they were living in a galaxy. The night sky would be much emptier of stars," said team member Aaron Romanowsky, of San Jose State University.
If you hold a lit match an inch or two over the smoking wick of a recently extinguished candle, the candle will light again. If you record that happening with a high speed camera and then slow it way down, it gives you some clues to how that happens:
Hint: wax is a candle's fuel and smoke is wax vapor... (via digg)
Here's a video of a titanium bar being anodized...it cycles through several different colors before settling on a pinkish hue.
Ok neat, but why does it do that? Anodizing is an adjustment of the oxide levels on the surface of the titanium. The colors are caused by the interference of the light traveling through the oxide and reflecting off the shiny metal surface underneath...different thicknesses produce different colors.1 As the voltage is applied to the metal, more and more oxide builds up, producing the color cycling even shown. Pretty cool!
From juice cleanses to vaccines to gluten to exercise to, uh, vagina steaming, celebrities like Jenny McCarthy and Gwyneth Paltrow are often found making claims that have little or no scientific evidence behind them. Timothy Caulfield recently wrote a book exploring the world of celebrity pseudoscience called Is Gwyneth Paltrow Wrong About Everything?
But while much has been written about the cause of our obsession with the rich and famous, Caulfield argues that not enough has been done to debunk celebrity messages and promises about health, diet, beauty, or the secret to happiness. From the obvious dangers, to body image of super-thin models and actors, or Gwyneth Paltrow's enthusiastic endorsement of a gluten free-diet for almost everyone, or Jenny McCarthy's ill-informed claims of the risks associated with vaccines, celebrity opinions have the power to dominate our conversations and outlooks on our lives and ourselves.
Julia Belluz of Vox interviewed Caulfield about the book.
JB: So is Gwyneth actually wrong about everything?
TC: It's incredible how much she is wrong about. Even when she is right about stuff -- like telling people to eat more fruits and vegetables -- there is always a bit of a tinge of wrongness. She'll say, "It has to be organic," for example. She is still distracting us with these untrue details, as opposed to just pushing the honest truth.
See also Your detoxing juice cleanse is bullshit.
Do you think you could ride a bicycle that steers backwards...aka it turns left when you turn right and vice versa? It sounds easy but years of normal bike riding experience makes it almost impossible. Destin Sandlin of Smarter Everyday taught himself how to ride the backwards-steering bike; it took months. Then he tried riding a normal bicycle again...
Loved this video...great stuff. (via ★interesting)
After years of the Flintstones lying to me, I'd just gotten used to the idea of the Brontosaurus not actually being a dinosaur. But a recent study of the classifications given to various species and genera within the diplodocid group of dinosaurs has determined that the Brontosaurus and the Apatosaurus are different enough to be two separate species.
Very broadly, their tree confirmed established ideas about the evolutionary relationships among diplodocids. But the scientists also concluded that Apatosaurus and Brontosaurus were different enough to belong in their own genera. Many of the anatomical differences between the two dinosaurs are obscure, Tschopp says, but Apatosaurus's stouter neck is an obvious one. "Even though both are very robust and massive animals, Apatosaurus is even more so," he adds.
Tschopp and his team thought very carefully about their decision to reinstate Brontosaurus, and they expect some pushback. "We knew it would be a major finding because Brontosaurus is such a popular name," he says. "I'm pretty sure there will be a scientific discussion around this. I hope there will be. That's how science works."
Huzzah! Now reinstate Pluto to full planetary status and we'll be all set. See also The Kindly Brontosaurus. (via @coudal)
In 1983, the BBC aired a six-part series called Fun to Imagine with a simple premise: put physicist Richard Feynman in front of a camera and have him explain everyday things. In this clip from one of the episodes, Feynman explains in very simple terms what fire is:
So good. Watch the whole thing...it seems like you get the gist about 2 minutes in, but that's only half the story. See also Feynman explaining rubber bands, how trains go around curves, and how magnets work.
James Krupa teaches a mandatory biology class at the University of Kentucky and some students have a difficult time because Krupa refuses to shy away from evolution.
Rarely do I have a Kentucky student who learned about human evolution in high school biology. Those who did usually attended high schools in large urban centers like Louisville or Lexington. Given how easily it can provoke parents, the teaching of human evolution is a rarity in high school, so much so in Kentucky that it startled me when I first arrived.
The story of our evolutionary history captivates many of my students, while infuriating some. During one lecture, a student stood up in the back row and shouted the length of the auditorium that Darwin denounced evolution on his deathbed -- a myth intentionally spread by creationists. The student then made it known that everything I was teaching was a lie and stomped out of the auditorium, slamming the door behind him. A few years later during the same lecture, another student also shouted out from the back row that I was lying. She said that no transitional fossil forms had ever been found -- despite my having shared images of many transitional forms during the semester. Many of her fellow students were shocked by her combativeness, particularly when she stormed out, also slamming the door behind her. Most semesters, a significant number of students abruptly leave as soon as they realize the topic is human evolution.
I personally don't understand the compatibility of evolutionary biology and Christianity Krupa emphasizes in his class, but I guess it helps to meet people halfway?
This article on the science of free diving is fascinating. Boyle's Law predicted that the human body couldn't survive depths past 100 feet -- after which, the lungs would rupture -- but millions of years of evolution has equipped the human body with all sorts of tricks to survive at depths of over 900 feet.
Lundgren, among others, demonstrated how these phenomena might counteract Boyle's law. He recruited volunteer firemen from a fire brigade in the Swedish city of Malmo, submerged them up to the neck in water, and used a heart catheter to measure the increase in blood circulation in the chest. Lundgren discovered the body was able to counteract the increased outside water pressure by reinforcing vessels in the walls of the lungs with more blood, in much the same way we increase tire pressure by adding more volume of oxygen to the inside of a tire.
Boyle's Law had not been overturned. Scientists simply hadn't taken into account the effect this counterforce could exert to allow survival underwater. "A lot of blood, much more than was usually thought, can be transferred from the blood circulation out in the tissues into the blood vessels of the lung," Lundgren said, placing that amount at about half a gallon. The extra, densely packed blood can act as a bulwark, exerting a counterforce against the increased pressure pushing inward by the water.
A group of astronomy enthusiasts rented a plane and flew through the shadow cast by the recent eclipse of the Sun. One passenger took the following video. Look at that shadow creeping across the cloud cover! So cool.
P.S. Still super excited for the 2017 eclipse! (via slate)
Ok, Pluto fans. They evicted Pluto from our solar system's planetary pantheon, but a NASA mission launched in 2006 is nearing the dwarf planet with its cameras. We'll soon have photos of Pluto that are much more high resolution than we currently have, which means scientists will need names for all the new geographic features. The Our Pluto site has been set up to help suggest and vote on names for these features. Naming themes include historic explorers, travelers to the underworld, and scientists and engineers. Go vote! (via slate)
Apparently, this is what it looks like when a lion is getting a CAT scan.
(via Amanda Macias)
This video, shot at 36,000 frames per second, shows a balloon popping underwater. I am not quite sure what I expected, but it wasn't this.
For instance, the air bubbles do not immediately rise to the surface...it takes them about 20-25 ms to get in the mood. Compare with a slow motion video of popping a water balloon in air:
Again, watch how it takes for gravity to kick in. It's like Wile E. Coyote after having run off a cliff, hanging in midair holding a sign that says "EEP!" (via @BadAstronomer)
Two teams of NASA scientists have discovered evidence that hydrothermal vents on the Saturnian moon of Enceladus show signs of "active hot-water chemistry". Why is that exciting? Because similar chemistry occurs deep in the Earth's oceans *and* can support life. Phil Plait explains.
We see these vents in the ocean bottom on Earth, too. The water there is very hot, heated by tectonic processes inside Earth's crust. It brings up minerals and nutrients, and life thrives there. A lot of the processes are the same as what's imagined is happening on Enceladus; minerals are dissolved in hot water that spews up into the cold ocean, precipitating out. A lot of it is sulfur based, but amazingly life exists there anyway. The environment is highly toxic to humans-huge pressure, boiling water near the vents, freezing a bit farther away, and loaded with icky chemicals-but as a scientist once said, "Life finds a way."
Between the evidence of past flowing water on Mars, Titan's hydrocarbon lakes, Europa's underground ocean, and Enceladus, it seems increasingly probable we'll find life somewhere else in the solar system. That's a pretty exciting prospect! (via @ericholthaus)
Update: It was also announced today that the Hubble has detected signs of a salty underground ocean on Jupiter's moon Ganymede.
New observations of the moon using Hubble support this. Ganymede has a weak magnetic field, and, like on Earth, this generates an aurora-the glow created when high-speed subatomic particles slam into the extremely thin atmosphere. This glow is brightest in ultraviolet, and so astronomers used the Space Telescope Imaging Spectrograph (my old camera!) on Hubble to observe Ganymede. STIS is quite sensitive to UV and detected the aurora.
Now this part is a bit tricky: Jupiter has a powerful magnetic field as well, which interacts with Ganymede's. As they do, the aurora changes position over time, moving up and down in latitude. However, the observations show that the aurorae do not change nearly as much as expected if Ganymede were solid. The best way to explain this is if the moon has a salty ocean under its surface. The ocean would have its own magnetic field and would resist the influence of Jupiter's magnetic field, which in turn keeps the aurora steadier.
Turns out there's water all over the place in the solar system. How about that?
Astronomers have been able to view the same supernova in a distant part of the Universe several times due to the gravitational lensing effect of a cluster of galaxies in-between here and there. From Dennis Overbye in the NY Times:
Supernovas are among the most violent and rare events in the universe, occurring perhaps once per century in a typical galaxy. They outshine entire galaxies, spewing elemental particles like oxygen and gold out into space to form the foundations of new worlds, and leaving behind crushed remnants called neutron stars or black holes.
Because of the galaxy cluster standing between this star and the Hubble, "basically, we got to see the supernova four times," Dr. Kelly said. And the explosion is expected to appear again in another part of the sky in the next 10 years. Timing the delays between its appearances, he explained, will allow astronomers to refine measurements of how fast the universe is expanding and to map the mysterious dark matter that supplies the bulk of the mass and gravitational oomph of the universe.
Scientists expect the supernova to reappear in the next few years. Gravitational lensing was predicted by Einstein's general theory of relativity and as Overbye writes, "the heavens continue to light candles for Albert Einstein."
For Scientific American, Jen Christiansen tracks down where the iconic image on the cover of Joy Division's Unknown Pleasures came from. Designer Peter Saville found the image, a stacked graph of successive radio signals from pulsar CP 1919, in a 1977 astronomy encyclopedia but it actually originated in a 1970 Ph.D. thesis.
By now I had also combed through early discovery articles in scientific journals and every book anthology on pulsars I could get my hands on to learn more about early pulsar visualizations. The more I learned, the more this descriptor in the 1971 Ostriker caption began to feel significant; "computer-generated illustration." The charts from Bell at Mullard were output in real time, using analogue plotting tools. A transition in technology from analogue to digital seemed to have been taking place between the discovery of pulsars in 1967 to the work being conducting at Arecibo in 1968 through the early 1970's. A cohort of doctoral students from Cornell University seemed to be embracing that shift, working on the cutting edge of digital analysis and pulsar data output. One PhD thesis title from that group in particular caught my attention, "Radio Observations of the Pulse Profiles and Dispersion Measures of Twelve Pulsars," by Harold D. Craft, Jr. (September 1970).
When a star gets old and fat, it explodes in a supernova, leaving a neutron star in its wake. Neutron stars are heavily magnetized and incredibly dense, approximately two times the mass of the Sun packed into an area the size of the borough of Queens. That's right around the density of an atomic nucleus, which isn't surprising given that neutron stars are mostly composed of neutrons. A teaspoon of neutron star would weigh billions of tons.
A pulsar is a neutron star that quickly rotates. As the star spins, electromagnetic beams are shot out of the magnetic poles, which sweep around in space like a lighthouse light. Pulsars can spin anywhere from once every few seconds to 700 times/second, with the surface speed approaching 1/4 of the speed of light. These successive waves of electromagnetic pulses, arriving every 1.34 seconds, are what's depicted in the stacked graph. Metaphorical meanings of its placement on the cover of a Joy Division record are left as an exercise to the reader.
The results of a major new trial, published in the New England Journal of Medicine, indicate that for children who are at risk of developing a peanut allergy, eating peanuts greatly reduces the chance of an allergy. This is pretty huge news.
All the babies were between 4 and 11 months old when they were enrolled, and all had either an egg allergy, severe eczema, or both-putting them at high risk of a peanut allergy down the road. Indeed, 98 of them were already heading in that direction: They tested positive for mild peanut sensitivity in a skin-prick test. This meant that these babies were already churning out antibodies to the peanut protein. Eating peanuts in the future could set off an allergic reaction.
The team divided the babies into two groups. Half were to avoid eating peanut products until they were 5 years old. The other half received at least 6 grams of peanut protein a week, spread across at least three meals, until they were 5 years old. Bamba was the preferred offering, though picky eaters who rejected it got smooth peanut butter.
Around the 5th birthdays of the trial subjects came the big test. The children consumed a larger peanut portion than they were used to in one sitting, and the results were clear-cut. Among 530 children who had had a negative skin-prick test when they were babies, 14% who avoided peanuts were allergic to them, compared with 2% of those who'd been eating them. In the even higher risk group, the children who were sensitized, 35% of the peanut-avoiders were allergic versus just over 10% of the peanut eaters.
Even if further studies confirm these results, will American parents start feeding their infants peanuts? I don't know...there are lots of similarities to vaccines in play here.
Update: Somewhat related: children in developed countries might be growing up too clean, making them more likely to develop allergies.
The findings are the latest to support the "hygiene hypothesis," a still-evolving proposition that's been gaining momentum in recent years. The hypothesis basically suggests that people in developed countries are growing up way too clean because of a variety of trends, including the use of hand sanitizers and detergents, and spending too little time around animals.
As a result, children don't tend to be exposed to as many bacteria and other microorganisms, and maybe that deprives their immune system of the chance to be trained to recognize microbial friend from foe.
That may make the immune system more likely to misfire and overreact in a way that leads to allergies, eczema and asthma, Hesselmar says.
Host Hank Green of the SciShow looks at the anti-vaccination movement from a scientific perspective: why are US parents growing less likely to vaccinate their children?
In psychology, the search for these explanations is called "Explanatory Attribution" and different people have different "explanatory styles". Some people are more prone to blame themselves, while others search for an external event to blame. But one thing is clear: we are very bad at not blaming anything. It's not surprising that parents of children with autism, especially parents who notice a sudden loss of previous development, will search for a possible cause. And when the most significant recent event in the health of the child was a vaccination, as can be said for many moments in the life of a young American, we might identify that as a potential cause and deem that link worthy of further examination.
Now this, is completely logical. The problem is that over a dozen peer-reviewed papers have found no correlation between autism and the MMR vaccine, or any other vaccine for that matter. And yet, when you Google vaccines and autism, a fair number of the results claim that there is a link between the two, and that that link is being covered up either by the government or by big corporations. A parent, already experiencing frustration with the medical community's inability to tell them why this thing has happened to their child, will, on the internet, find a vibrant community of similarly frustrated people who share their values and experiences. These communities are full of anecdotes that draw connections between vaccines and autism. And so, unsurprisingly, some people become convinced that they have found the reason for their child's disability.
Once their mind has been made up, confirmation bias sets in. Confirmation bias is simply our tendency to more readily, and with less scrutiny, accept information, anecdotes, and world views that confirm our existing beliefs. And, again, it is a completely normal thing that every person does. Indeed, trying to convince someone that a previously held belief is incorrect has been proven to actually increase their affinity for that idea. And so a community is born, and the safety of vaccines is called into question. And once the procedure for getting a vaccine goes from the doctor telling you that it is now time for a vaccine -- and 99% of parents agreeing because that person went through medical school -- to it being a question to ponder, vaccination rates will go down.
The Spaceprob.es site tracks the active probes in operation in and around our solar system, from Voyager I (19.56 billion km from Earth) to the Artemis probes (358,000 km away). (via @BadAstronomer)
Update: Spaceprob.es now has a shop with posters, pillows, t-shirts, and stickers.
A recent paper by three climate scientists concludes there's a high risk of an unprecedented drought in the Southwest and Midwest United States later this century, even if we manage to get our carbon emissions under control. The scientists say it'll be drier in the Western US than at any point in the past 1000 years.
In the Southwest and Central Plains of Western North America, climate change is expected to increase drought severity in the coming decades. These regions nevertheless experienced extended Medieval-era droughts that were more persistent than any historical event, providing crucial targets in the paleoclimate record for benchmarking the severity of future drought risks. We use an empirical drought reconstruction and three soil moisture metrics from 17 state-of-the-art general circulation models to show that these models project significantly drier conditions in the later half of the 21st century compared to the 20th century and earlier paleoclimatic intervals. This desiccation is consistent across most of the models and moisture balance variables, indicating a coherent and robust drying response to warming despite the diversity of models and metrics analyzed. Notably, future drought risk will likely exceed even the driest centuries of the Medieval Climate Anomaly (1100-1300 CE) in both moderate (RCP 4.5) and high (RCP 8.5) future emissions scenarios, leading to unprecedented drought conditions during the last millennium.
Eric Holthaus has the layperson's explanation of the study and its implications.
Smerdon's study is the first to examine the future risk of "megadrought" in the southwest and central United States in the context of historical episodes of drought in the same regions. Smerdon's study suggests that the coming years are likely to see droughts worse than the epic dry periods that are thought to have caused profound changes to human settlement in the region over the last millennium.
"They're 'mega' because they are droughts that lasted in these regions for multiple decades," said Smerdon in an interview with Slate. "We haven't seen anything like this since at least the 1400s." In comparison, the current California drought is four years old, though drought has been present in most of the last 15 years somewhere in the West.
Update: This NASA video provides a quick overview of this study and what it means for our climate.
From the Physics arXiv Blog, a list of paradoxes in modern cosmological physics, i.e. areas where theory and observation disagree, sometimes by a whopping 120 orders of magnitude.
Perhaps the most dramatic, and potentially most important, of these paradoxes comes from the idea that the universe is expanding, one of the great successes of modern cosmology. It is based on a number of different observations.
The first is that other galaxies are all moving away from us. The evidence for this is that light from these galaxies is red-shifted. And the greater the distance, the bigger this red-shift.
Astrophysicists interpret this as evidence that more distant galaxies are travelling away from us more quickly. Indeed, the most recent evidence is that the expansion is accelerating.
What's curious about this expansion is that space, and the vacuum associated with it, must somehow be created in this process. And yet how this can occur is not at all clear. "The creation of space is a new cosmological phenomenon, which has not been tested yet in physical laboratory," says Baryshev.
What's more, there is an energy associated with any given volume of the universe. If that volume increases, the inescapable conclusion is that this energy must increase as well. And yet physicists generally think that energy creation is forbidden.
Baryshev quotes the British cosmologist, Ted Harrison, on this topic: "The conclusion, whether we like it or not, is obvious: energy in the universe is not conserved," says Harrison.
This is a problem that cosmologists are well aware of. And yet ask them about it and they shuffle their feet and stare at the ground. Clearly, any theorist who can solve this paradox will have a bright future in cosmology.
Luckily, these paradoxes are an opportunity to do some great science.
Nothing is faster than the speed of light. But compared to the unimaginable size of the Universe, light is actually extremely slow. This video is 45 minutes long and during that time, a photon emitted from the Sun1 will only travel through a portion of our solar system.
In our terrestrial view of things, the speed of light seems incredibly fast. But as soon as you view it against the vast distances of the universe, it's unfortunately very slow. This animation illustrates, in realtime, the journey of a photon of light emitted from the sun and traveling across a portion of the solar system.
It takes light more than 43 minutes to travel to Jupiter and even to travel the diameter of the Sun takes 4.6 seconds. (thx, andy)
Administrators at Palm Desert High School in California have banned 66 students who never got measles vaccinations.
"I think some parents see it as a personal choice, like homeschooling. But when you choose not to vaccinate, you're putting other children at risk." From WaPo: Why this baby's mom is so angry at the anti-vaxxers.
"I respect people's choices about what to do with their kids, but if someone's kid gets sick and gets my kid sick, too, that's a problem." A Marin County father has demanded that his district keep unvaccinated kids out of school.
Vox: How an Amish missionary caused 2014's massive measles outbreak.
Bonus tweet: "If my kid can't bring peanut butter to school, yours shouldn't be able to bring preventable diseases."
Using ice-penetrating radar and ice cores, NASA has been able to map the layers in the Greenland ice sheet.
This new map allows scientists to determine the age of large swaths of Greenland's ice, extending ice core data for a better picture of the ice sheet's history. "This new, huge data volume records how the ice sheet evolved and how it's flowing today," said Joe MacGregor, a glaciologist at The University of Texas at Austin's Institute for Geophysics and the study's lead author.
Greenland's ice sheet is the second largest mass of ice on Earth, containing enough water to raise ocean levels by about 20 feet. The ice sheet has been losing mass over the past two decades and warming temperatures will mean more losses for Greenland. Scientists are studying ice from different climate periods in the past to better understand how the ice sheet might respond in the future.
One way of studying this distant past is with ice cores. These cylinders of ice drilled from the ice sheet hold evidence of past snow accumulation and temperature and contain impurities like dust and volcanic ash that were carried by snow that accumulated and compacted over hundreds of thousands of years. These layers are visible in ice cores and can be detected with ice-penetrating radar.
Ice-penetrating radar works by sending radar signals into the ice and recording the strength and return time of reflected signals. From those signals, scientists can detect the ice surface, sub-ice bedrock and layers within the ice.
New techniques used in this study allowed scientists to efficiently pick out these layers in radar data. Prior studies had mapped internal layers, but not at the scale made possible by these newer, faster methods. Another major factor in this study was the amount of Greenland IceBridge has measured.
It's amazing that the detectors and data analysis are sensitive enough to pick out different layers in the ice just from radar. (via @ptak)
From the Russian Space Agency, a video of what the sky would look like if the Sun were replaced by some other stars. It starts off with the binary star system of Alpha Centuri, but watch until the end for Polaris, which has a radius 46 times that of the Sun.
See also the view from Earth of different planets replacing the Moon and imagining Earth with Saturn's rings.
A map published by Bernard Porter in 1939 depicting physics as a landmass through which several rivers corresponding to the main branches (light, sound, heat, etc.) run and converge into one.
This simulator evolves increasingly effective walking creatures through genetic algorithms. After each round, the winners are sent through to the next round and copied by the rest of the competitors, with mutations introduced. At first, the pace of improvement is swift -- two orders of magnitude within 100 generations -- but slows pretty dramatically after that. (via @nickrichter)
Scientists have discovered the first promising new antibiotic in 25 years. And even better, says Ed Yong, is that the antibiotic in question is "resistant to resistance".
A team of scientists led by Kim Lewis from Northeastern University have identified a new antibiotic called teixobactin, which kills some kinds of bacteria by preventing them from building their outer coats. They used it to successfully treat antibiotic-resistant infections in mice. And more importantly, when they tried to deliberately evolve strains of bacteria that resist the drug, they failed. Teixobactin appears resistant to resistance.
Bacteria will eventually develop ways of beating teixobactin -- remember Orgel -- but the team are optimistic that it will take decades rather than years for this to happen. That buys us time.
...and also that the process by which teixobactin was discovered is the real breakthrough:
Teixobactin isn't even the most promising part of its own story. That honour falls on the iChip-the tool that the team used to discover the compound. Teixobactin is a fish; the iChip is the rod. Having the rod guarantees that we'll get more fish-and we desperately need more.
Buzzfeed's Carolyn Kylstra asked some scientists and medical professionals about juice cleanses and while they are (mostly) harmless, they definitely don't do any of the magical things you think they do, like flush the toxins out of your body or reset your system.
"I don't know why someone would do a juice cleanse," Dr. John Buse, M.D., Ph.D., chief of the division of endocrinology at the University of North Carolina at Chapel Hill, told BuzzFeed Life. "There's very little evidence that it does anything good for you."
And it definitely won't "rid your body of toxins." That really is what your liver (and your kidneys and intestines) is for. "I don't like the marketing around juice cleanses," Eric Ravussin, Ph.D., associate executive director for clinical science at Pennington Biomedical Research Center, told BuzzFeed Life. "That it's going to detox and mobilize all these toxins and all that -- this is pure marketing."
Update: From the NY Times in 2009, Flush Those Toxins! Eh, Not So Fast. The last paragraph makes me angry:
Still, many people swear by these programs. Denise Whitney, 37, a registered nurse and mother of three in Traverse City, Mich., did the Master Cleanse over a seven-day period, plus six days of pre and post cleanse, which included consuming copious amounts of organic juice, fruit and vegetables. "With all the fast food, preservatives, chemicals in our food, it seems impossible that our bodies are not loaded with toxins," Ms. Whitney said, adding that she plans to repeat it in the next few months. "I had more energy during this cleanse than I can ever remember having."
Can we get this nurse unregistered, please? FFS. But at The Guardian, Oliver Burkeman cautions against over-debunking.
We live in the Age of Debunking: no sooner has somebody made a false or hyperbolic claim online (resulting in clicks) than someone else announces, with an air of triumph, that they've debunked it (resulting in clicks). I plead guilty. And often enough, debunking is a noble pursuit: the idea that we only use 10% of our brains, to pick one example, is flat wrong, and people who believe it ought to be corrected. No convincing evidence of a Benghazi conspiracy has ever been unearthed. Marie Antoinette almost certainly didn't say "let them eat cake".
But the internet's enthusiasm for a vigorous debunking now frequently spills over into what you might call the pseudo-debunk. Sometimes, this involves cynically claiming you're debunking when you're really just disagreeing -- thereby implying that your opinion is more than mere opinion; it's "the facts".
Update: Tara Fuller of Greatist writes I've Tried Almost Every Cleanse. Here's Why I'll Never Do One Again:
2. Eating fruit is much healthier than drinking it.
While juice cleanses may seem like an easy way to load up on vitamins and minerals, they're often full of added sugars and devoid of the good stuff (like fiber and antioxidants). Juicing fruits does tend to preserve some vitamins, but why guzzle several hundred calories worth of fruit when you can eat one serving and actually feel full? Plus, all that juice can actually lead to type 2 diabetes-whereas eating fruit reduces the risk!
(via @fakejoshstein & @neversent & @alainabrowne)
The Hubble Space Telescope was launched 25 years ago, and to start the celebration, NASA has released a pair of images that actually did make this space nerd's jaw drop. The first is an update of a classic: a much sharper photo of the so-called Pillars of Creation:
Although NASA's Hubble Space Telescope has taken many breathtaking images of the universe, one snapshot stands out from the rest: the iconic view of the so-called "Pillars of Creation." The jaw-dropping photo, taken in 1995, revealed never-before-seen details of three giant columns of cold gas bathed in the scorching ultraviolet light from a cluster of young, massive stars in a small region of the Eagle Nebula, or M16.
The second image isn't so immediately amazing but is my favorite of the two. It's a photo of half of the Andromeda galaxy, the big galaxy closest to our own in distance but also in rough size and shape. Here's a very very scaled-down version of it:
The largest NASA Hubble Space Telescope image ever assembled, this sweeping view of a portion of the Andromeda galaxy (M31) is the sharpest large composite image ever taken of our galactic neighbor. Though the galaxy is over 2 million light-years away, the Hubble telescope is powerful enough to resolve individual stars in a 61,000-light-year-long section of the galaxy's pancake-shaped disk. It's like photographing a beach and resolving individual grains of sand. And, there are lots of stars in this sweeping view -- over 100 million, with some of them in thousands of star clusters seen embedded in the disk.
The original image is 1500 megapixels (1.5 gigapixels!), which is so big that you'd need 600 HD televisions to display the whole thing. But if you take the biggest reasonable size available for download (100 megapixels) and zoom in on it, you get this:
That looks like JPEG compression noise, right? Nope, each one of those dots is a star...some of the 100 million individual stars that can be seen in the full image.
That's right, Keanu. Whoa. For an even closer look, check out this annotated close-up released by NASA:
If you're curious and feel like crashing your browser and/or Photoshop a bunch of times (I did not), the full-res Andromeda images are available here. And Phil Plait writes much more joyfully and knowledgeably about these images than I do...go take a look at his Pillars of Creation and Andromeda posts.
Update: Rob Griffiths took 50+ photos from the Hubble web site and made them into Retina iMac-sized wallpapers. (via @djacobs)
From astrophysicist Robert Simpson, a tour of the Universe from humans to the largest structure of the Universe. The piece is full of interesting little bits like:
The average female is 1.62 metres [tall] -- that's 5.4 light-nanoseconds.
If the Earth was a beach ball then all life on Earth exists within just 1mm around the surface.
Out by Pluto, the Sun itself is has dimmed to look like an other stars.
If the Sun was a blood cell then the Milky Way is the size of Europe.
See also Steven Strogatz on the Sagan Planet Walk in Ithaca, NY.
As you stroll from one to another, you can't help noticing that the first four planets are really close together. It takes a few seconds, a few tens of steps, to walk from the Sun to Mercury and then on to Venus, Earth and Mars. By contrast, Jupiter is a full two-minute walk down the block, just past Moosewood Restaurant, waiting for someone to stop by and admire it. The remaining planets are even lonelier, each marooned in its own part of town. The whole walk, from the Sun to Pluto, is about three-quarters of a mile long and takes about 15 minutes.
My favorite detail: they added a new station to the Sagan Walk, the star nearest to our solar system. It's in Hawaii.
As a young graduate student, Brian Greene caught the very beginning of the superstring revolution in physics. 30 years later, Greene provides an accessible overview of string theory's current status.
While spectacularly successful at predicting the behavior of atoms and subatomic particles, the quantum laws looked askance at Einstein's formulation of gravity. This set the stage for more than a half-century of despair as physicists valiantly struggled, but repeatedly failed, to meld general relativity and quantum mechanics, the laws of the large and small, into a single all-encompassing description.
Such was the case until December 1984, when John Schwarz, of the California Institute of Technology, and Michael Green, then at Queen Mary College, published a once-in-a-generation paper showing that string theory could overcome the mathematical antagonism between general relativity and quantum mechanics, clearing a path that seemed destined to reach the unified theory.
The idea underlying string unification is as simple as it is seductive. Since the early 20th century, nature's fundamental constituents have been modeled as indivisible particles-the most familiar being electrons, quarks and neutrinos-that can be pictured as infinitesimal dots devoid of internal machinery. String theory challenges this by proposing that at the heart of every particle is a tiny, vibrating string-like filament. And, according to the theory, the differences between one particle and another -- their masses, electric charges and, more esoterically, their spin and nuclear properties -- all arise from differences in how their internal strings vibrate.
A major study conducted by the Harvard School of Public Health has found a significant link between autism and the exposure of the mother to high levels of air pollution during the third trimester of pregnancy.
Researchers focused on 1,767 children born from 1990 to 2002, including 245 diagnosed with autism. The design of the study and the results rule out many confounding measures that can create a bias, Weisskopf said. The researchers took into account socioeconomic factors that can influence exposure to pollution or play a role in whether a child is diagnosed with autism.
The fact that pollution caused problems only during pregnancy strengthened the findings, since it's unlikely other factors would have changed markedly before or after those nine months, he said in a telephone interview.
The ultimate cause of autism remains a mystery in most cases, said Charis Eng, chairwoman of the Lerner Research Institute's Genomic Medicine Institute at the Cleveland Clinic in Ohio. While the Harvard study isn't definitive and the findings could be coincidental, it's not likely given the large size and the precise results, she said in a telephone interview.
"The truth is there has to be gene and environmental interactions," said Eng, who wasn't involved in the study. "I suspect the fetus already had the weak autism spectrum disorder genes, and then the genes and the environment interacted."
It would be a huge help (and I am not in any way being facetious about this) if Jenny McCarthy and all the other celebrity "vaccines cause autism" folks threw their weight behind cleaning up pollution the way they attacked vaccination. Redeem yourselves. (via @john_overholt)
There's no blue pigment present in the wings of the morpho butterfly. So where does that shimmering brilliant blue color come from? It's an instance of structural color, where the physical structure of the surface scatters or refracts only certain wavelengths of light...in this case, blue.
Eye color is another example of structural color in action. Eyes contain brown pigments but not blue. Blue, green, and hazel eyes are caused by Rayleigh scattering, the same phenomenon responsible for blue skies and red sunsets. Blue eyes and blue skies arise from the same optical process...that's almost poetic. (thx, jared)
According to a recent paper, as little as 12 seconds of video is enough to identify a particular shooter's personal "motion signature".
Here's a way to shake off anonymity - literally. Footage from wearable cameras contains a "motion signature" unique to you. The discovery could identify police wearing body cameras, but also let authorities single out protesters uploading footage, say.
Physics World, the magazine of the Institute of Physics, has named their 2014 Breakthrough of the Year and nine runners-up. The top spot goes to the ESA's Rosetta mission for landing on a comet.
By landing the Philae probe on a distant comet, the Rosetta team has begun a new chapter in our understanding of how the solar system formed and evolved -- and ultimately how life was able to emerge on Earth. As well as looking forward to the fascinating science that will be forthcoming from Rosetta scientists, we also acknowledge the technological tour de force of chasing a comet for 10 years and then placing an advanced laboratory on its surface.
The other nine achievements, which you can click through to read about, are:
Quasar shines a bright light on cosmic web
Neutrinos spotted from Sun's main nuclear reaction
Laser fusion passes milestone
Electrons' magnetic interactions isolated at long last
Disorder sharpens optical-fibre images
Data stored in magnetic holograms
Lasers ignite 'supernovae' in the lab
Quantum data are compressed for the first time
Physicists sound-out acoustic tractor beam
From Quora, an answer to the question "If we pour water on the sun with a bucket as big as the sun, will the sun be extinguished?"
The probable answer is "no." The Sun involves a special type of fire that is able to "burn" water, and so it will just get hotter, and six times brighter.
Water is 89% oxygen BY MASS. And the Sun's overall density is 1.4 times that of water. So if you have a volume of water the VOLUME of the Sun, it will have 1/1.4 = 0.71 times the mass of the Sun, and this mass will be .71*.89 = 63% of a solar mass of oxygen and 8% of a solar mass of hydrogen. The Sun itself is 0.74 solar masses of hydrogen and 0.24 solar masses of helium.
So you end up with a 1.7 solar mass star with composition 48% hydrogen, 37% oxygen, and 14% helium (with 1% heavier elements).
Now, will such a star burn? Yes, but not with the type of proton-proton fusion the Sun uses. A star 1.7 times the mass of the Sun will heat up and burn almost entirely by the CNO fusion cycle, after making some carbon and nitrogen to go along with all the oxygen you've started with. So with CNO fusion and that mass you get a type F0 star with about 1.3 times the radius and 6 times the luminosity of the present Sun, and a temperature somewhat hotter than the Sun (7200 K vs. the Sun's 5800 K). It will be bluish-white, with more UV. That, along with that 6 times heat input, will cause the Earth's biosphere to be fried, and oceans to probably boil.
Well, we probably shouldn't do that then. (via gizmodo)
Whilst roving about Mars, Curiosity has slowly but surely racked up evidence for a past Mars that was warm, wet, and possibly habitable.
John P. Grotzinger of Caltech, the project scientist for the mission, reported at a news conference on Monday that the rover's yearlong trek to Mount Sharp provided strong new evidence that Gale Crater had large lakes, rivers and deltas, on and off, for millions to tens of millions of years. The geology shows that even when the surface water dried up, plenty of water would have remained underground, he said.
Moreover, the team concluded, numerous deltalike and lakelike formations detected by orbiting satellites are almost certainly the dried remains of substantial ancient lakes and deltas. None of this proves that life existed on the planet, but the case for an early Mars that was ripe and ready for life has grown stronger.
"As a science team, Mars is looking very attractive to us as a habitable planet," Dr. Grotzinger said in an interview. "Not just sections of Gale Crater and not just a handful of locations, but at different times around the globe."
See also the interactive 28 Months on Mars.
Update: And right on cue, Curiosity has recorded a two-month-long methane burst on Mars. One explanation for the methane is that it's a waste product of living organisms.
The presence of methane is significant because the gas cannot exist for long. Calculations indicate that sunlight and chemical reactions in the Martian atmosphere would break up the molecules within a few hundred years, so any methane there now must have been created recently.
It could have been created by a geological process known as serpentinization, which requires both heat and liquid water. Or it could be a product of life in the form of microbes known as methanogens, which release methane as a waste product.
Even if the explanation for the methane turns out to be geological, the hydrothermal systems would still be prime locations to search for signs of life.
Update: And now Curiosity has found "biologically useful nitrogen" on Mars.
There is no evidence to suggest that the fixed nitrogen molecules found by the team were created by life. The surface of Mars is inhospitable for known forms of life. Instead, the team thinks the nitrates are ancient, and likely came from non-biological processes like meteorite impacts and lightning in Mars' distant past.
Features resembling dry riverbeds and the discovery of minerals that form only in the presence of liquid water suggest that Mars was more hospitable in the remote past. The Curiosity team has found evidence that other ingredients needed for life, such as liquid water and organic matter, were present on Mars at the Curiosity site in Gale Crater billions of years ago.
"Finding a biochemically accessible form of nitrogen is more support for the ancient Martian environment at Gale Crater being habitable," said Jennifer Stern of NASA's Goddard Space Flight Center in Greenbelt, Maryland.
Update: The analysis of a year of weather and soil data collected by Curiosity indicates that a small amount of liquid water could exist below the surface of Mars.
Martian weather and soil conditions that NASA's Curiosity rover has measured, together with a type of salt found in Martian soil, could put liquid brine in the soil at night.
Perchlorate identified in Martian soil by the Curiosity mission, and previously by NASA's Phoenix Mars Lander mission, has properties of absorbing water vapor from the atmosphere and lowering the freezing temperature of water. This has been proposed for years as a mechanism for possible existence of transient liquid brines at higher latitudes on modern Mars, despite the Red Planet's cold and dry conditions.
New calculations were based on more than a full Mars year of temperature and humidity measurements by Curiosity. They indicate that conditions at the rover's near-equatorial location were favorable for small quantities of brine to form during some nights throughout the year, drying out again after sunrise. Conditions should be even more favorable at higher latitudes, where colder temperatures and more water vapor can result in higher relative humidity more often.
The Guardian and other media outlets have translated this news into Nasa's Curiosity rover finds water below surface of Mars even though NASA's release clearly states "we have not detected brines". Come on, guys.
A shell found in the 1890s was recently found to have what scientists are calling the world's oldest "abstract marking", a 500,000-year-old etching made by Homo erectus, an extinct ancestor of modern humans.
Close inspection under the microscope suggested that the engraving was intentional. The weathering patterns of the grooves, each of which is about 1 centimetre long, show signs of significant ageing, and there are no gaps between turns, indicating that the maker paid attention to detail. He or she probably made the engraving on a fresh shell, and the newly made etching would have resembled white lines on a dark canvas, Joordens' team notes. Sand grains still embedded in the shell were dated to around 500,000 years ago.
It turns out if you break some kinds of slow-growing corals into tiny pieces, these microfragments grow much much faster than usual, even 25-50 times faster.
"Part of the coral had grown over the back side and had attached to the bottom of the aquarium," he said. When he grabbed it, "it broke off and left two or three polyps behind. I thought I just killed those. But oh, well, I moved the puck over."
A week later he happened to glance at the abandoned polyps -- the individual hydra-shaped, genetically identical organisms that make up a coral colony -- on the bottom of the aquarium. "I noticed that those one to three polyps were now five to seven polyps," he said. "They not only had lived -- they had grown and had doubled in size."
It was, he said, "my eureka mistake." He cut a few more polyps from the original colony and placed them on other pucks. "And they grew like crazy. The coral seems to want to repair itself quickly and grow back over its lost ground before something else takes its territory."
Both this and the article about the quickly regenerating corals I posted last month seem to hinge on a realization scientists have had recently about coral: what matters most is the surface area, not the volume. You look at a massive brain coral and you think the whole thing is the organism, but most of it is just a base for the thin layer of stuff coating it that actually matters.
A new analysis of the genomes of two extinct human species (Neanderthals and Denisovans) shows more clearly that they interbred with our species of human, contributing 2-4% of our modern genomes in some cases.
"What it begins to suggest is that we're looking at a Lord of the Rings-type world -- that there were many hominid populations," says Mark Thomas, an evolutionary geneticist at University College London who was at the meeting but was not involved in the work.
But, more interestingly, the analysis also detected the Denisovans also bred with an as-yet-unknown species of humans.
The Denisovan genome indicates that the population got around: Reich said at the meeting that as well as interbreeding with the ancestors of Oceanians, they also bred with Neanderthals and the ancestors of modern humans in China and other parts of East Asia. Most surprisingly, Reich said, the genomes indicate that Denisovans interbred with yet another extinct population of archaic humans that lived in Asia more than 30,000 years ago -- one that is neither human nor Neanderthal.
Is this the first time a new human species has been discovered through DNA evidence alone?
Google Research built an interactive periodic table of the elements where you can see the relative amounts of the elements as found in the human body, in the sea, and, most interestingly, by the number of mentions in books.
If you've ever wondered why the periodic table is shaped the way it is, click on "electrons" under "Shape" and pay attention to the number of electrons in the outer shells in each column of elements. Amazingly, when Dmitri Mendeleev and German chemist Julius Meyer published the first periodic tables in 1869/1870, the elements were organized only by atomic weights and chemical properties; they didn't know what an electron was and certainly weren't aware of quantum shells of electrons. (via @djacobs)
Photographer Ernie Button photographs the dried remains of single malt scotch whiskies, which end up looking like desolate landscapes on distant worlds.
Curious as to how these patterns were formed by some kinds of whiskey but not others, Button reached out to an engineering professor at Princeton.
Dr. Stone's group found that the key difference in whisky is that unlike coffee, it consists of two liquids -- water and ethyl alcohol. The alcohol evaporates more quickly, and as the fraction of water increases, the surface tension of the droplet changes, an effect first noticed in the 19th century by an Italian scientist, Carlo Marangoni. That, in turn, generates complex flows that contribute to the patterns Mr. Button photographed.
"Here, they actually looked at what happens when you change the fluids that are drying," said Dr. Yunker, who is soon heading to the Georgia Institute of Technology as a physics professor, "and they found some very neat effects." (That would be neat in the usual sense of "cool and intriguing" and not as in "I'll have my whisky neat.")
Now this is an ambitious Kickstarter project: Lunar Mission One wants to send an unmanned probe to an unexplored area of the Moon, land on the surface, drill a hole at least 20 meters in depth to analyze geological composition of the Moon, and then drop a time capsule in the hole that will last 1 billion years. That's. Insane.
We're going to use pioneering technology to drill down to a depth of at least 20m -- 10 times deeper than has ever been drilled before -- and potentially as deep as 100m. By doing this, we will access lunar rock dating back up to 4.5 billion years to discover the geological composition of the Moon, the ancient relationship it shares with our planet and the effects of asteroid bombardment. Ultimately, the project will improve scientific understanding of the early solar system, the formation of our planet and the Moon, and the conditions that initiated life on Earth.
The Rosetta mission has opened the way for a new era of pioneering space exploration and demonstrates the public appetite to engage with the secrets of the solar system. We want this to be a truly international mission that everyone everywhere can get involved in, so we are using Kickstarter to finance the next phase of development. This is your chance to be part of Lunar Mission One and to reserve your place in space. Your pledge will reserve you a digital memory box that will be buried in the moon during the mission as part of a 21st Century time capsule.
This is a great way to think about how big the planets of our solar system are: in terms of fruits.
(via boing boing)
A European Space Agency landing craft the size of a washing machine is scheduled to land on a comet tomorrow, November 12, 2014. How cool is that?
Never before has a space mission put a lander on a comet. But the European Space Agency (ESA) plans to change that. Its Rosetta craft has been orbiting comet 67P/Churyumov-Gerasimenko since August and is set to release the washing-machine-sized lander, Philae, on 12 November. This would set in motion a nail-biting seven-hour fall designed to deliver Philae to a landing site called Agilkia on the comet's surface. Philae is programmed to beam data and images back to Earth to help scientists to understand comets, including whether these conglomerations of ice, rock and dust supplied our planet with water and other building blocks of life when they smashed into it billions of years ago.
You can watch the landing live (or here too)...touch down on the comet's surface is scheduled for 11:03 AM EST. Here's a full rundown of the events on landing day. Good luck, Philae!
Update: Randall Munroe of XKCD is live drawing the landing.
Kip Thorne is a theoretical physicist who did some of the first serious work on the possibility of travel through wormholes. Several years ago, he resigned as the Feynman Professor of Theoretical Physics from Caltech in part to make movies. To that end, Thorne acted as Christopher Nolan's science advisor for Interstellar. As a companion to the movie, Thorne wrote a book called The Science of Interstellar.
Yet in The Science of Interstellar, Kip Thorne, the physicist who assisted Nolan on the scientific aspects of Interstellar, shows us that the movie's jaw-dropping events and stunning, never-before-attempted visuals are grounded in real science. Thorne shares his experiences working as the science adviser on the film and then moves on to the science itself. In chapters on wormholes, black holes, interstellar travel, and much more, Thorne's scientific insights -- many of them triggered during the actual scripting and shooting of Interstellar -- describe the physical laws that govern our universe and the truly astounding phenomena that those laws make possible.
Wired has a piece on how Thorne and Nolan worked together on the film. Phil Plait was unimpressed with some of the science in the movie, although he retracted some of his criticism. If you're confused by the science or plot, Slate has a FAQ.
Update: Well, well, the internet's resident Science Movie Curmudgeon Neil deGrasse Tyson actually liked the depiction of science in Interstellar. In particular: "Of the leading characters (all of whom are scientists or engineers) half are women. Just an FYI." (via @thoughtbrain)
Update: What's wrong with "What's Wrong with the Science of Movies About Science?" pieces? Plenty says Matt Singer.
But a movie is not its marketing; regardless of what 'Interstellar''s marketing said, the film itself makes no such assertions about its scientific accuracy. It doesn't open with a disclaimer informing viewers that it's based on true science; in fact, it doesn't open with any sort of disclaimer at all. Nolan never tells us exactly where or when 'Interstellar' is set. It seems like the movie takes place on our Earth in the relatively near future, but that's just a guess. Maybe 'Interstellar' is set a million years after our current civilization ended. Or maybe it's set in an alternate dimension, where the rules of physics as Phil Plait knows them don't strictly apply.
Or maybe 'Interstellar' really is set on our Earth 50 years in the future, and it doesn't matter anyway because 'Interstellar' is a work of fiction. It's particularly strange to see people holding 'Interstellar' up to a high standard of scientific accuracy because the movie is pretty clearly a work of stylized, speculative sci-fi right from the start.
This is a time lapse of the surface of the Sun, constructed of more than 17,000 images taken by the Solar Dynamics Observatory from Oct 14 to Oct 30, 2014. The bright area that starts on the far right is sunspot AR 12192, the largest observed sunspot since 1990.
The sunspot is about 80,000 miles across (as wide as 10 Earths) and it's visible from Earth with the naked eye. Best viewed as large as possible...I bet this looks amazing on the new retina iMac. (via @pageman)
A children's book about space featuring information graphics illustrated by the completely awesome Jennifer Daniel!?
The third in a visually stunning series of information graphics that shows just how interesting and humorous scientific information can be. Complex facts about space are reinterpreted as stylish infographics that astonish, amuse, and inform.
INSTANT PURCHASE. February 2015 cannot come fast enough.
In 2013, a group of researchers published a paper called Collective Motion of Moshers at Heavy Metal Concerts. The paper's abstract reads:
Human collective behavior can vary from calm to panicked depending on social context. Using videos publicly available online, we study the highly energized collective motion of attendees at heavy metal concerts. We find these extreme social gatherings generate similarly extreme behaviors: a disordered gas-like state called a mosh pit and an ordered vortex-like state called a circle pit. Both phenomena are reproduced in flocking simulations demonstrating that human collective behavior is consistent with the predictions of simplified models.
The authors built an interactive mosh pit simulation based on their simplified models. You can try it out right here:
If you believe in gravity, then you know that if you remove air resistance, a bowling ball and a feather will fall at the same rate. But seeing it actually happen, in the world's largest vacuum chamber (122 feet high, 100 feet in diameter), is still a bit shocking.
In the late 1500s, Galileo was the first to show that the acceleration due to the Earth's gravity was independent of mass with his experiment at the Leaning Tower of Pisa, but that pesky air resistance caused some problems. At the end of the Apollo 15 mission, astronaut David Scott dropped a hammer and a feather in the vacuum on the surface of the Moon:
In a rare bit of good news about climate change, it appears that some types of coral have the ability to recover more quickly from trauma caused by rising ocean temperatures (archive).
At Palau in the western Pacific, a survey completed just three years after the 1998 bleaching event showed more coral had recovered on reefs within protected bays and on deep slopes.
Scientists suggest this is because heat and light serve as a double-whammy to coral health and corals that hang out in shady zones will escape the scorching combination, upping the chances that remnants will survive.
Seven years after the bleaching event, some reefs had regained nearly 40 per cent of their corals, with two species of plate-like acroporid coral, A. digitifera and A. hyacinthus, particularly prevalent. "We sampled plating coral colonies there a few years ago and found them to be pool-table size," says Stephen Palumbi, Director of Stanford University's Hopkins Marine Station, in Pacific Grove, California, US.
Today's Google Doodle honors Jonas Salk on what would have been his 100th birthday. Salk developed the first successful polio vaccine in 1955 and was hailed as a hero for it.
On April 12, 1955, Dr. Thomas Francis, Jr., of the University of Michigan, the monitor of the test results, "declared the vaccine to be safe and effective." The announcement was made at the University of Michigan, exactly 10 years to the day after the death of President Roosevelt. Five hundred people, including 150 press, radio, and television reporters, filled the room; 16 television and newsreel cameras stood on a long platform at the back; and 54,000 physicians, sitting in movie theaters across the country, watched the broadcast on closed-circuit television. Eli Lilly and Company paid $250,000 to broadcast the event. Americans turned on their radios to hear the details, department stores set up loudspeakers, and judges suspended trials so that everyone in the courtroom could hear. Europeans listened on the Voice of America. Paul Offit writes about the event:
"The presentation was numbing, but the results were clear: the vaccine worked. Inside the auditorium Americans tearfully and joyfully embraced the results. By the time Thomas Francis stepped down from the podium, church bells were ringing across the country, factories were observing moments of silence, synagogues and churches were holding prayer meetings, and parents and teachers were weeping. One shopkeeper painted a sign on his window: Thank you, Dr. Salk. 'It was as if a war had ended', one observer recalled."
Because of Salk's vaccine and subsequent vaccines, the US has been polio-free since 1979.
Lockheed Martin is in the process of developing a compact fusion reactor they say could revolutionize the world's energy industry.
Dubbed the compact fusion reactor (CFR), the device is conceptually safer, cleaner and more powerful than much larger, current nuclear systems that rely on fission, the process of splitting atoms to release energy. Crucially, by being "compact," Lockheed believes its scalable concept will also be small and practical enough for applications ranging from interplanetary spacecraft and commercial ships to city power stations. It may even revive the concept of large, nuclear-powered aircraft that virtually never require refueling-ideas of which were largely abandoned more than 50 years ago because of the dangers and complexities involved with nuclear fission reactors.
The key difference in Lockheed's approach seems to be the configuration of the magnetic field containing the reaction:
The CFR will avoid these issues by tackling plasma confinement in a radically different way. Instead of constraining the plasma within tubular rings, a series of superconducting coils will generate a new magnetic-field geometry in which the plasma is held within the broader confines of the entire reaction chamber. Superconducting magnets within the coils will generate a magnetic field around the outer border of the chamber. "So for us, instead of a bike tire expanding into air, we have something more like a tube that expands into an ever-stronger wall," McGuire says. The system is therefore regulated by a self-tuning feedback mechanism, whereby the farther out the plasma goes, the stronger the magnetic field pushes back to contain it. The CFR is expected to have a beta limit ratio of one. "We should be able to go to 100% or beyond," he adds.
Charles Seife, who wrote a book about the history of fusion, is skeptical of Lockheed's claims.
This week, Lockheed Martin supposedly managed to achieve a "breakthrough" in nuclear fusion that has gotten a lot of media attention. As Charles Seife points out, it did so "without having built a prototype device that, you know, fuses things on an appreciable scale. It's a stunning assertion, even by fusion-research standards. But a quick look at the defense contractor's ambitious plan-a working reactor in five years-already shows the dream fraying around the edges. A year and a half ago, the company promised that fusion was four years away, meaning that the schedule is already slipping. Negative one years of progress in 20 months is, sadly, business as usual for fusion. At this rate, it'll take Lockheed Martin at least a decade before the natural endpoint: desperately spinning victory out of an underwhelming result generated by a machine whose performance comes nowhere near predictions-and which brings us no closer to actually generating energy from a fusion reaction."
This is fun...Aatish Bhatia maps out the forces and motions involved in doing an ollie on a skateboard.
It's a neat piece of science art, and it also tells us something interesting. The arrows show us that the force on the skateboard is constantly changing, both in magnitude as well as in direction. Now the force of gravity obviously isn't changing, so the reason that these force arrows are shrinking and growing and tumbling around is that the skater is changing how their feet pushes and pulls against the board. By applying a variable force that changes both in strength and direction, they're steering the board.
Gorgeous videos of chemical reactions (precipitation, bubbling, crystallization, etc.). I think the metal displacement reaction video is my favorite:
The sound made by the Krakatoa volcanic eruption in 1883 was so loud it ruptured eardrums of people 40 miles away, travelled around the world four times, and was clearly heard 3,000 miles away.
Think, for a moment, just how crazy this is. If you're in Boston and someone tells you that they heard a sound coming from New York City, you're probably going to give them a funny look. But Boston is a mere 200 miles from New York. What we're talking about here is like being in Boston and clearly hearing a noise coming from Dublin, Ireland. Travelling at the speed of sound (766 miles or 1,233 kilometers per hour), it takes a noise about 4 hours to cover that distance. This is the most distant sound that has ever been heard in recorded history.
A much much smaller eruption occurred recently in Papua New Guinea. From the video, you can get a tiny sense of the sonic damage unleashed by Krakatoa:
Holy smoking Toledos indeed. On Reddit, a user details how loud a Saturn V rocket is and what the effects would be at different distances. At very close range, the sound from the Saturn V measures an incredible 220 db, loud enough to melt concrete just from the sound.
At 500 meters, 155 db you would experience painful, violent shaking in your entire body, you would feel compressed, as though deep underwater. Your vision would blur, breathing would be very difficult, your eardrums are obviously a lost cause, even with advanced active noise cancelling protection you could experience permanent damage. This is the sort of sound level aircraft mechanics sometimes experience for short periods of time. Almost twice as "loud" as putting your ear up to the exhaust of a formula 1 car. The air temperature would drop significantly, perhaps 10-25 degrees F, becoming suddenly cold because of the air being so violently stretched and moved.
Even at three miles away, the sound is loud enough to cause permanent hearing damage. But that's nothing compared to the Krakatoa sound. The Saturn V sound is ~170 db at 100 meters away while the Krakatoa explosion was that loud 100 miles away! What happens at 170 db?
...you would be unable to breathe or likely see at all from the sound pressure, glass would shatter, fog would be generated as the water in the air dropped out of suspension in the pressure waves, your house at this distance would have a roughly 50% chance of being torn apart from sound pressure alone. Military stun grenades reach this volume for a split second... if they are placed up to your face. Survival chance from sound alone, minimal, you would certainly experience permanent deafness but probably also organ damage.
The word "loud" is inadequate to describe how loud that is. (thx, david)
Every year, evolutionary biologist and professor David Barash gives his students The Talk about how evolution and religion do and do not get along.
It's irresponsible to teach biology without evolution, and yet many students worry about reconciling their beliefs with evolutionary science. Just as many Americans don't grasp the fact that evolution is not merely a "theory," but the underpinning of all biological science, a substantial minority of my students are troubled to discover that their beliefs conflict with the course material.
Until recently, I had pretty much ignored such discomfort, assuming that it was their problem, not mine. Teaching biology without evolution would be like teaching chemistry without molecules, or physics without mass and energy. But instead of students' growing more comfortable with the tension between evolution and religion over time, the opposite seems to have happened. Thus, The Talk.
This is the sort of thing Barash talks about:
The more we know of evolution, the more unavoidable is the conclusion that living things, including human beings, are produced by a natural, totally amoral process, with no indication of a benevolent, controlling creator.
Eleanor Lutz has a degree in molecular biology, works as a designer, and loves to combine the two interests by making these wonderful information graphics on her site, Tabletop Whale. Her most recent post is an animated graphic showing how several animals (birds, bats, insects) move their wings while flying.
I love love love Lutz's animated chart of North American butterflies. So playful!
There are only four posts on the site so far, but she's done other stuff as well; this woodcut map for instance. Prints are available...I'm getting one of the butterflies for sure.
Give me even the simplest gravity simulator and I will play with it for many many minutes. Or hours. Or days. (Send help!)
This looks like a time lapse, but it's not. It's just a straight-up gorgeous video of the aurora borealis filmed in Yellowknife, Northwest Territories, Canada.
It is real time motion! NOT time-lapse. Brighter the Aurora, faster the movement.
(via the kid should see this)
Erik Vance on why real working archaeologists don't care for Indiana Jones.
"Oh God," he groans, "Don't even go there. Indiana Jones is not an archeologist."
It's not surprising that academics -- hell bent on taking the fun out of everything -- would hate our beloved and iconic movie version of them. But Canuto is no killjoy. His ironic tone and acerbic wit seem honed by long boring days in the sun. So I bite. I quickly learn that there's a good reason why most every archeologist on Earth hates Indy. And that they might have a point. Because Jones isn't an archeologist at all.
"That first scene, where he's in the temple and he's replacing that statue with a bag of sand -- that's what looters do," Canuto says, grinning. "[The temple builders] are using these amazing mechanisms of engineering and all he wants to do is steal the stupid gold statue."
Makes you wonder if Jones was one of the Raiders referred to in the title of the first movie. (via @riondotnu)
As part of a course he was teaching, a biologist sent away for a genetic testing kit from 23andMe for himself and his parents. When he went looking for other relatives on the service (which is now an automatic opt-out feature), he discovered he had a half-brother his dad had not told his family about.
At first, I was thinking this is the coolest genetics story, my own personal genetics story. I wasn't particularly upset about it initially, until the rest of the family found out. Their reaction was different. Years of repressed memories and emotions uncorked and resulted in tumultuous times that have torn my nuclear family apart. My parents divorced. No one is talking to my dad. We're not anywhere close to being healed yet and I don't know how long it will take to put the pieces back together.
After this discovery was made, I went back to 23andMe and talked to them. I said, "I'm not sure all your customers realize that when they participate in your family finder program, what they're participating in what are essentially really advanced paternity tests." People find out that their parents aren't who they think they are. They have nearly a million people in the database. If there happens to be anyone in there you're related to, they'll find your match. This is a solid science.
I know a family in which one of the children is adopted and they haven't told her. Which is crazy...she's gonna find out eventually (through something like 23andMe or because of some medical emergency or test) and go totally berzerk.
There's a new king of the dinosaurs: Dreadnoughtus schrani. A skeleton of the species was unearthed in Argentina in 2005 and the results of the recently released analysis show this Dreadnoughtus was 85 feet long, weighed around 65 tons, and had a powerful "weaponized tail". The kicker? It was not yet an adult and still growing when it died.
While other giants from Patagonia are known from a handful of bones, almost half of the Dreadnoughtus skeleton has been recovered. What's more, the fossilised bones are in such good condition -- even revealing where muscles attached -- that the skeleton could provide unprecedented insights into the biology, movement and evolution of the group of huge plant-eating dinosaurs it belonged to, called the titanosaurian sauropods.
By comparison, an Apatosaurus (née Brontosaurus) is ~75 feet long and weighed 22 tons while a Boeing 737-900 weights around 50 tons. Here's some more background on the Dreadnoughtus and a video showing some of the fossils:
Hmm, this is interesting. Recent studies suggest that food allergies may be caused by the absense of certain intestinal bacteria...in part due to increased use of antibiotics in very young children.
Food allergies have increased about 50% in children since 1997. There are various theories explaining why. One is that the 21st century lifestyle, which includes a diet very different from our ancestors', lots of antibiotic use, and even a rise in cesarean section deliveries, has profoundly changed the makeup of microbes in the gut of many people in developed countries. For example, the average child in the United States has taken three courses of antibiotics by the time he or she is 2 years old, says Martin Blaser, an infectious disease specialist and microbiologist at New York University in New York City. (See here for more on the reach of microbiome research these days.)
Cathryn Nagler, an immunologist at the University of Chicago in Illinois, has spent years probing links between the immune system, intestinal bacteria, and the onset of allergies. Back in 2004, she and her colleagues reported that wiping out gut bacteria in mice led to food allergies. Since then, Nagler has continued trying to understand which bacteria offer allergy protection and how they accomplish that.
Spanning from comets in the south to the termination shock zone in the northern part of the country, The Sweden Solar System is a scale model of the solar system that spans the entire country of Sweden, the largest such model in the world.
The Sun is represented by the Ericsson Globe in Stockholm, the largest hemispherical building in the world. The inner planets can also be found in Stockholm but the outer planets are situated northward in other cities along the Baltic Sea.
Today's brain-melter: Every Insanely Mystifying Paradox in Physics. It's all there, from the Greisen-Zatsepin-Kuzmin limit to quantum immortality to, of course, the tachyonic antitelephone.
A tachyonic antitelephone is a hypothetical device in theoretical physics that could be used to send signals into one's own past. Albert Einstein in 1907 presented a thought experiment of how faster-than-light signals can lead to a paradox of causality, which was described by Einstein and Arnold Sommerfeld in 1910 as a means "to telegraph into the past".
If you emerge with your brain intact, at the very least, you'll have lost a couple of hours to the list.
Oh man, this is great. A Spacecraft For All is an interactive video about the ISEE-3 Reboot Project, in which a group of scientists working out of an old McDonald's crowdfunded an effort to communicate with a nearly forgotten satellite launched by NASA in 1978 to observe the Sun and chase a comet. After the intro, click on "See the Journey"...it's well worth your time if you're at all interested in space or science.
For instance, did you know there exists several points between the Earth and the Sun at which a satellite can orbit around, enabling spacecraft to stay more or less in the same spot for observation purposes? So cool!
The latest word on Homo floresiensis, the potential new species of hobbit-like humans discovered ten years ago in Indonesia, concerns a pair of papers which argue the single specimen found is actually a regular human with Down syndrome.
Now, the debate has reignited with two new papers published this week by a team of researchers from Penn State and other institutions. In one of those papers, they argue that the Flores skull is not a new species, but instead represents an ancient person with Down syndrome.
The researchers also point out, in the second paper, that the original report on the bones seemed to have exaggerated the skull's diminutive size. Cranial measurements and features, along with shorter thigh bones, the team found, all correspond with modern manifestations of Down syndrome. "The difference is significant, and the revised figure falls in the range predicted for a modern human with Down syndrome from the same geographic region," they say in a statement.
Physicist Andy Howell recently gave a talk about the science of Star Wars and wrote up a summary of it for Ain't It Cool News. Topics covered include binary star systems, droids, the Death Star, and lightsabers:
Of course, we still don't know how to make a lightsaber. One big problem is confining plasma (if that is even what it is), into some tube. But a bigger problem is the amount of energy required. We can actually calculate this from clues in the movies!
In Episode I, Qui-Gon jabs his lightsaber into a door, and melts part of it. That's just basic physics! To melt something, you have to raise its temperature to the melting point, and you can calculate how much energy that takes using the specific heat capacity of a material.
MIT's Franz-Josef Ulm has taken to analyzing the structure of cities as if they were molecular materials like glass or crystal.
With colleagues, Ulm began analyzing cities the way you'd analyze a material, looking at factors such as the arrangement of buildings, each building's center of mass, and how they're ordered around each other. They concluded that cities could be grouped into categories: Boston's structure, for example, looks a lot like an "amorphous liquid." Seattle is another liquid, and so is Los Angeles. Chicago, which was designed on a grid, looks like glass, he says; New York resembles a highly ordered crystal.
I love this. It's like Jane Jacobs + the materials science research I did in college.
So far, Ulm says, the work has two potential applications. First, it could help predict and mitigate urban heat island effects, the fact that cities tend to be several degrees warmer than their surrounding areas-a phenomenon that has a major impact on energy use. (His research on how this relates to structure is currently undergoing peer review.) Second, he says that cities' molecular order (or disorder) may also affect their vulnerability to the kinds of catastrophic weather events that are becoming more frequent thanks to climate change.
(via 5 intriguing things)
According to data collected by a European satellite array, the Earth's magnetic field is shifting and weakening at a greater pace than previously thought. One of the reasons for the shift might be that the magnetic North and South poles are swapping positions.
Scientists already know that magnetic north shifts. Once every few hundred thousand years the magnetic poles flip so that a compass would point south instead of north. While changes in magnetic field strength are part of this normal flipping cycle, data from Swarm have shown the field is starting to weaken faster than in the past. Previously, researchers estimated the field was weakening about 5 percent per century, but the new data revealed the field is actually weakening at 5 percent per decade, or 10 times faster than thought. As such, rather than the full flip occurring in about 2,000 years, as was predicted, the new data suggest it could happen sooner.
You can read up on geomagnetic reversals on Wikipedia. A short sampling:
These periods [of polarity] are called chrons. The time spans of chrons are randomly distributed with most being between 0.1 and 1 million years with an average of 450,000 years. Most reversals are estimated to take between 1,000 and 10,000 years. The latest one, the Brunhes-Matuyama reversal, occurred 780,000 years ago. A brief complete reversal, known as the Laschamp event, occurred only 41,000 years ago during the last glacial period. That reversal lasted only about 440 years with the actual change of polarity lasting around 250 years. During this change the strength of the magnetic field dropped to 5% of its present strength.
Earlier today I asked my Twitter followers for recommendations for "really good" biographies about scientists. I gave Genius (James Gleick's bio of Richard Feynman) and Cleopatra, A Life (not about a scientist but was super interesting and well-written) as examples of what I was looking for. You can see the responses here and I've pulled out a few of the most interesting ones below:
- Isaac Newton by James Gleick. Gleick wrote the aforementioned Genius and Chaos, another favorite of mine. I tried to read The Information last year after many glowing recommendations from friends but couldn't get into it. Someone suggested Never at Rest is a superior Newton bio.
- The Man Who Loved Only Numbers by Paul Hoffman. I've read this biography of mathematician Paul Erdos; highly recommended.
- Galileo's Daughter by Dava Sobel. I've never read anything by Sobel; I'll have to rectify that.
- Einstein: His Life and Universe by Walter Isaacson. I enjoyed his problematic Jobs biography and I notice that he's written one on Ben Franklin as well.
- Alan Turing: The Enigma by Andrew Hodges.
- American Prometheus by Kai Bird and Martin Sherwin. Bio of J. Robert Oppenheimer, leader of the Manhattan Project. See also: The Making of the Atomic Bomb, one of my favorite books ever.
- Everything and More by David Foster Wallace. I've heard Wallace was bit handwavy with the math in this one, but I still enjoyed it.
- Newton and the Counterfeiter by Thomas Levenson. Newton was a detective?
- The Philosophical Breakfast Club by Laura Snyder. Four-way bio of a group of school friends (Charles Babbage, John Herschel, William Whewell, and Richard Jones) who changed the world.
- The Reluctant Mr. Darwin by David Quammen. How Charles Darwin devised his theory of evolution and then sat on it for years is one of science's most fascinating stories.
- T. rex and the Crater of Doom by Walter Alvarez. Not a biography of a person but of a theory: that a meteor impact 65 million years ago caused the extinction of the dinosaurs.
- Walt Disney by Neal Gabler. Disney isn't a scientist, but when you ask for book recommendations and Steven Johnson tells you to read something, it goes on the list.
- The Man Who Knew Infinity by Robert Kanigel. Bio of brilliant Indian mathematician Srinivasa Ramanujan.
- Edge of Objectivity by Charles Gillispie. A biography of modern science published in 1966, all but out of print at this point unfortunately.
- Galileo at Work by Stillman Drake.
- The Age of Wonder by Richard Holmes.
And many more here. Thanks to everyone who suggested books.
Update: Because this came up on Twitter, some biographies specifically about women in science: The Immortal Life of Henrietta Lacks, Hedy's Folly, On a Farther Shore, Marie Curie: A Life, A Feeling for the Organism, Rosalind Franklin: The Dark Lady of DNA, Jane Goodall: The Woman Who Redefined Man, and Radioactive.
Great post on the Fermi Paradox, aka if there are so many potential intelligent civilizations out there in the universe (possibly 10 quadrillion of them), why haven't we heard from anyone?
Possibility 5) There's only one instance of higher-intelligent life -- a "superpredator" civilization (like humans are here on Earth) -- who is far more advanced than everyone else and keeps it that way by exterminating any intelligent civilization once they get past a certain level. This would suck. The way it might work is that it's an inefficient use of resources to exterminate all emerging intelligences, maybe because most die out on their own. But past a certain point, the super beings make their move -- because to them, an emerging intelligent species becomes like a virus as it starts to grow and spread. This theory suggests that whoever was the first in the galaxy to reach intelligence won, and now no one else has a chance. This would explain the lack of activity out there because it would keep the number of super-intelligent civilizations to just one.
Update: If you prefer to watch engaging videos instead of reading text, here's six minutes on the Fermi Paradox:
Aatish Bhatia noticed a plant in his backyard whose leaves naturally repelled water. He took a sample to a friend who had access to a high-speed camera and an electron microscope to investigate what made the leaves so hydrophobic.
But how does a leaf become superhydrophobic? The trick to this, Janine explained, is that the water isn't really sitting on the surface. A superhydrophobic surface is a little like a bed of nails. The nails touch the water, but there are gaps in between them. So there's fewer points of contact, which means the surface can't tug on the water as much, and so the drop stays round.
The leaf is so water repellant that drops of water bounce right off of it:
In the New Yorker, Michael Specter writes generally about the malleability of memory and specifically about Daniela Schiller's research on disassociating people's memories from the feelings they have about them. Simply recalling a memory can change it, and Schiller has found evidence that process can be used to remove the feelings of stress, anxiety, and fear associated with certain memories.
Even so, Schiller entered her field at a fortunate moment. After decades of struggle, scientists had begun to tease out the complex molecular interactions that permit us to form, store, and recall many different types of memories. In 2004, the year Schiller received her doctorate in cognitive neuroscience, from Tel Aviv University, she was awarded a Fulbright fellowship and joined the laboratory of Elizabeth Phelps, at New York University. Phelps and her colleague Joseph LeDoux are among the nation's leading investigators of the neural systems involved in learning, emotion, and memory. By coincidence, that was also the year that the film "Eternal Sunshine of the Spotless Mind" was released; it explores what happens when two people choose to have all their memories of each other erased. In real life, it's not possible to pluck a single recollection from our brains without destroying others, and Schiller has no desire to do that. She and a growing number of her colleagues have a more ambitious goal: to find a way to rewrite our darkest memories.
"I want to disentangle painful emotion from the memory it is associated with," she said. "Then somebody could recall a terrible trauma, like those my father obviously endured, without the terror that makes it so disabling. You would still have the memory, but not the overwhelming fear attached to it. That would be far more exciting than anything that happens in a movie." Before coming to New York, Schiller had heard -- incorrectly, as it turned out -- that the idea for "Eternal Sunshine" originated in LeDoux's lab. It seemed like science fiction and, for the most part, it was. As many neuroscientists were aware, though, the plot also contained more than a hint of truth.
The black hole at the center of the Milky Way galaxy is estimated to have a mass of 4 million Suns. The largest black hole astronomers have found so far has a mass of 18 billion solar masses, or more than 4000 times as massive as the Milky Way's.
Around 3.5 billion light-years away, this galaxy is estimated to contain the largest black hole presently known, at 18 billion solar masses. (Although, the error bars for this one and NGC 1277's overlap substantially.) But the most spectacular part of this galaxy -- and why we're able to learn so much about it's central region -- is because there's a 100 million Solar mass black hole (that's 25 times larger than the one at the Milky Way's core) that's orbiting the even larger one!
Also, the largest know galaxy in the Universe is IC 1101, with a mass of 100 trillion solar masses.
A group led by Dr. Robert Costanza has calculated the value of the world's ecosystems...the group's most recent estimate puts the yearly value at $142.7 trillion.
"I think this is a very important piece of science," said Douglas J. McCauley of the University of California, Santa Barbara. That's particularly high praise coming from Dr. McCauley, who has been a scathing critic of Dr. Costanza's attempt to put price tags on ecosystem services.
"This paper reads to me like an annual financial report for Planet Earth," Dr. McCauley said. "We learn whether the dollar value of Earth's major assets have gone up or down."
The group last calculated this value back in 1997 and it rose sharply over the past 17 years, even as those natural habitats are disappearing. This line from the article stunned me:
Dr. Costanza and his colleagues estimate that the world's reefs shrank from 240,000 square miles in 1997 to 108,000 in 2011.
Coral reefs shrank by more than half over the past 17 years...I had no idea the reef situation was that bad. Jesus.
A proposal by geochemist Ellen Kooijman for a minifigure set of female scientists has won Lego's Winter 2014 Review. The set, called "Research Institute," is on track to be released by Lego Ideas in August 2014, more than two years after a campaign that took off with huge support from the internet.
Kooijman designed twelve figures in total, plus accessories. Lego will tweak the final designs and hasn't announced the specific characters or total number that will be included. Kooijman's proposed set includes an astronomer, a paleontologist, and a chemist:
Me, I'm a fan of the robotics engineer (pictured below, right, with a falconer and geologist):
Lego already has one female scientist minifigure, released just last fall (after Koojiman's original proposal). She's a chemist/theoretician, with the typical
glasses (safety glasses! according to materials scientist Deb Chachra), pocket protector, and laboratory flasks. But scientists have all kinds of tools and look all sorts of different ways, even broader than Kooijman's all-yellow/caucasian team with generic Lego hair. ("Ideally, Lego would use some 'rare' face and hair designs if they were to produce a set," she writes.)
Besides, go back and look at the composition of some of Lego's other sets to see if it could use more than one female scientist. Minifigure Series 1 had sixteen characters, with the two women being "Cheerleader" and "Nurse." The "Scientist" just came out in Series 11, along with "Grandma," [ok fine] "Pretzel Girl," [really?] "Diner Waitress," [ugh!] and the admittedly awesome "Lady Robot," who loves to party. "Some day she might decide she's ready to stop partying...but not yet!" Go ahead, be gone with it, Lady Robot.
Update: The retail version of the Lego Research Institute has arrived! It's Kooijman's original trio of paleontologist, astronomer, and chemist, with tweaked designs and accessories. Here's a picture:
It is sad to see Gwyneth Paltrow promoting pseduoscience hucksters like Masaru Emoto in her very popular Goop newsletter. It begins:
I am fascinated by the growing science behind the energy of consciousness and its effects on matter. I have long had Dr. Emoto's coffee table book on how negativity changes the structure of water, how the molecules behave differently depending on the words or music being expressed around it.
And later on in the letter, Dr. Habib Sadeghi continues:
Japanese scientist, Masaru Emoto performed some of the most fascinating experiments on the effect that words have on energy in the 1990's. When frozen, water that's free from all impurities will form beautiful ice crystals that look exactly like snowflakes under a microscope. Water that's polluted, or has additives like fluoride, will freeze without forming crystals. In his experiments, Emoto poured pure water into vials labeled with negative phrases like "I hate you" or "fear." After 24 hours, the water was frozen, and no longer crystallized under the microscope: It yielded gray, misshapen clumps instead of beautiful lace-like crystals. In contrast, Emoto placed labels that said things like "I Love You," or "Peace" on vials of polluted water, and after 24 hours, they produced gleaming, perfectly hexagonal crystals. Emoto's experiments proved that energy generated by positive or negative words can actually change the physical structure of an object.
Riiiight. Paltrow should stick to recipes, fashion, and workouts and leave the science to people who actually understand it lest she wander into Jenny McCarthy territory. There's nothing wrong with asserting that thinking positively will improve your life, but connecting it with quantum physics and the like, without rigorous scientific proof, is dangerous and stupid.
Steven Johnson has been working on a six-part series for PBS called How We Got to Now. (There's a companion book as well.) The series is due in October but the trailer dropped today:
And here's a snippet of one of the episodes about railway time. I'm quite looking forward to this series; Johnson and I cover similar ground in our work with similar sensibilities. I'm always cribbing stuff from his writing and using his frameworks to think things through and just from the trailer, I counted at least three things I've covered on kottke.org in the past: Hedy Lamarr, urban sanitation, and Jacbo Riis (not to mention all sorts of stuff about time).
There are a couple of different ways you can construct a stable solar system with a maximum number of habitable worlds. One includes 36 habitable worlds in a single solar system.
We can fit the orbits of four gas giants in the habitable zone (in 3:2 resonances). Each of those can have up to five potentially habitable moons. Plus, the orbit of each gas giant can also fit an Earth-sized planet both 60 degrees in front and 60 degrees behind the giant planet's orbit (on Trojan orbits). Or each could be a binary Earth! What is nice about this setup is that the worlds can have any size in our chosen range. It doesn't matter for the stability.
Let's add it up. One gas giant per orbit. Five large moons per gas giant. Plus, two binary Earths per orbit. That makes 9 habitable worlds per orbit. We have four orbits in the habitable zone. That makes 36 habitable worlds in this system!
If there wasn't life on Mars before, there might be now. Before NASA sent Curiosity to Mars, it was thoroughly cleaned of all traces of contaminants. But swabs of rover's surfaces taken before it was sent to Mars have revealed 377 different strains of bacteria that potentially could have made the trip. Some of them may have even survived.
A study that identified 377 strains found that a surprising number resist extreme temperatures and damage caused by ultraviolet-C radiation, the most potentially harmful type. The results, presented today at the annual meeting of the American Society for Microbiology, are a first step towards elucidating how certain bacteria might survive decontamination and space flight.
If the Moon orbited the Earth at the same distance as the International Space Station, it might look a little something like this:
At that distance, the Moon would cover half the sky and take about five minutes to cross the sky. Of course, as Phil Plait notes, if the Moon were that close, tidal forces would result in complete chaos for everyone involved.
There would be global floods as a tidal wave kilometers high sweeps around the world every 90 minutes (due to the Moon's closer, faster orbit), scouring clean everything in its path. The Earth itself would also be stretched up and down, so there would be apocalyptic earthquakes, not to mention huge internal heating of the Earth and subsequent volcanism. I'd think that the oceans might even boil away due to the enormous heat released from the Earth's interior, so at least that spares you the flood... but replaces water with lava. Yay?
Jupiter's Great Red Spot is becoming more of a Medium Red Spot. The gas giant's signature beauty mark was recently measured by the Hubble as spanning 10,250 miles across its widest point, down from a high of 25,500 miles across.
Historic observations as far back as the late 1800s  gauged this turbulent spot to span about 41 000 kilometres at its widest point -- wide enough to fit three Earths comfortably side by side. In 1979 and 1980 the NASA Voyager fly-bys measured the spot at a shrunken 23 335 kilometres across. Now, Hubble has spied this feature to be smaller than ever before.
"Recent Hubble Space Telescope observations confirm that the spot is now just under 16 500 kilometres across, the smallest diameter we've ever measured," said Amy Simon of NASA's Goddard Space Flight Center in Maryland, USA.
Amateur observations starting in 2012 revealed a noticeable increase in the spot's shrinkage rate. The spot's "waistline" is getting smaller by just under 1000 kilometres per year. The cause of this shrinkage is not yet known.
Clive Thompson recently saw the moons of Jupiter with his own eyes and has a moment.
I saw one huge, bright dot, with three other tiny pinpoints of light nearby, all lined up in a row (just like the image at the top of this story). Holy moses, I realized; that's no star. That's Jupiter! And those are the moons of Jupiter!
I'm a science journalist and a space buff, and I grew up oohing and aahing over the pictures of Jupiter sent back by various NASA space probes. But I'd never owned a telescope, and never done much stargazing other than looking up in the night unaided. In my 45 years I'd never directly observed Jupiter and its moons myself.
So I freaked out. In a good way! It was a curiously intense existential moment.
For my birthday when I was seven or eight, my dad bought me a telescope. (It was a Jason telescope; didn't everyone have a telescope named after them?) We lived in the country in the middle of nowhere where it was nice and dark, so over the next few years, we looked at all sorts of celestial objects through that telescope. Craters on the Moon, the moons of Jupiter, Mars, and even sunspots on the Sun with the aid of some filters. But the thing that really got me, that provided me with my own version of Thompson's "curiously intense existential moment", was seeing the rings of Saturn through a telescope.
We had heard from PBS's Jack Horkheimer, the Star Hustler, that Saturn and its rings would be visible and he showed pictures of what it would look like, something like this:
But seeing that with your own eyes through a telescope was a different thing entirely. Those tiny blurry rings, visible from millions of miles away. What a thrill! It's one of my favorite memories.
For the first time, scientists have created a living cell with DNA containing more than just the familiar A, T, C, and G units.
Hailed as a breakthrough by other scientists, the work is a step towards the synthesis of cells able to churn out drugs and other useful molecules. It also raises the possibility that cells could one day be engineered without any of the four DNA bases used by all organisms on Earth.
"What we have now is a living cell that literally stores increased genetic information," says Floyd Romesberg, a chemical biologist at the Scripps Research Institute in La Jolla, California, who led the 15-year effort.
So instead of just using the GATTACA alphabet, scientists may eventually gain the use of an alphabet containing dozens or even hundreds or thousands of different letters. Potentially powerful stuff.
How to Build a Time Machine is a documentary about two men on separate quests to build their own time machines. Here's a teaser trailer:
Ronald Mallett's reason for his search for a way to travel through time is quite poignant...he shared his story in a book and on an episode of This American Life back in 2007. (via ★interesting)
According to the National Climate Assessment, climate change has already affected the US in significant ways. This map from the NY Times shows the change in temperatures from around the country, specifically the "1991-2012 average temperature compared with 1901-1960 average".
Among the report's findings? As I've noted before, weather is getting weirder and more bursty, not just hotter.
One of the report's most striking findings concerned the rising frequency of torrential rains. Scientists have expected this effect for decades because more water is evaporating from a warming ocean surface, and the warmer atmosphere is able to hold the excess vapor, which then falls as rain or snow. But even the leading experts have been surprised by the scope of the change.
The report found that the eastern half of the country is receiving more precipitation in general. And over the past half-century, the proportion of precipitation that is falling in very heavy rain events has jumped by 71 percent in the Northeast, by 37 percent in the Midwest and by 27 percent in the South, the report found.
Nonlinear systems, man.
The elements located in the upper reaches of the periodic table are notable for their short half-lives, the amount of time during which half the mass of an element will decay into lighter elements (and other stuff). For instance, the longest lived isotope of fermium (#100) has a half-life of just over 100 days. More typical is bohrium (#107)...its half-life is only 61 seconds. The elements with the highest numbers have half-lives measured in milliseconds...the half-life of ununoctium (#118) is only 0.89 milliseconds.
So why do chemists and physicists keep looking for heavier and heavier elements if they are increasingly short-lived (and therefore not that useful)? Because they suspect some heavier elements will be relatively stable. Let's take a journey to the picturesque island of stability.
In nuclear physics, the island of stability is a set of as-yet undiscovered heavier isotopes of transuranium elements which are theorized to be much more stable than some of those closer in atomic number to uranium. Specifically, they are expected to have radioactive decay half-lives of minutes or days, with "some optimists" expecting half-lives of millions of years.
Super Planet Crash is half game, half planetary simulator in which you try to cram as much orbital mass into your solar system without making any of your planets zing off beyond the Kuiper belt. You get bonus points for crowding planets together and locating planets in the star's habitability zone. Warning: I got lost in this for at least an hour the other day.
Ruh-roh. Remember the news last month about the detection of gravitational waves would have allowed scientists to see all the way back to the Big Bang? Well, that result may be in jeopardy. The problem? Dust on the lens. Well, not on the lens exactly:
An imprint left on ancient cosmic light that was attributed to ripples in spacetime -- and hailed by some as the discovery of the century -- may have been caused by ashes from an exploding star.
In the most extreme scenario, the finding could suggest that what looked like a groundbreaking result was only a false alarm. Another possibility is that the stellar ashes could help bring the result in line with other cosmic observations. We should know which it is later this year, when researchers report new results from the European Space Agency's Planck satellite.
You may also remember the video of physicist Andrei Linde being told about the result, which seemed to confirm a theory that had been his life's work. I don't think I want to see the video of Linde being told of this stellar ashes business. Although Linde is more than aware that this is how science works...you have to go where observation takes you. (via @daveg)
The US Navy is working on technology to convert seawater into fuel to power unmodified combustion engines. They recently tested the fuel (successfully!) in a replica P-51 and hope to make it commerically viable.
Navy researchers at the U.S. Naval Research Laboratory (NRL), Materials Science and Technology Division, demonstrated proof-of-concept of novel NRL technologies developed for the recovery of carbon dioxide (CO2) and hydrogen (H2) from seawater and conversion to a liquid hydrocarbon fuel.
Fueled by a liquid hydrocarbon -- a component of NRL's novel gas-to-liquid (GTL) process that uses CO2 and H2 as feedstock -- the research team demonstrated sustained flight of a radio-controlled (RC) P-51 replica of the legendary Red Tail Squadron, powered by an off-the-shelf (OTS) and unmodified two-stroke internal combustion engine.
Using an innovative and proprietary NRL electrolytic cation exchange module (E-CEM), both dissolved and bound CO2 are removed from seawater at 92 percent efficiency by re-equilibrating carbonate and bicarbonate to CO2 and simultaneously producing H2. The gases are then converted to liquid hydrocarbons by a metal catalyst in a reactor system.
"In close collaboration with the Office of Naval Research P38 Naval Reserve program, NRL has developed a game-changing technology for extracting, simultaneously, CO2 and H2 from seawater," said Dr. Heather Willauer, NRL research chemist. "This is the first time technology of this nature has been demonstrated with the potential for transition, from the laboratory, to full-scale commercial implementation."
Discover has more, in slightly more accessible language.
After many days of analysis by scientists and internet sleuths alike, it's likely that the thing pictured whizzing by the skydiver in this video is not a meteorite but a plain old rock that got packed in with his parachute. Phil Plait reports:
I actually became convinced last night, when BA Tweep Helge Bjorkhaug sent me a link to a slowed-down version of the video. Immediately before the rock flies past, I saw a second piece of debris just to the right of the skydiver's parachute strap. It was in several frames, and clearly real.
So yeah, bummer, not a meteorite. But as Plait notes, that's how science works.
That's how you get to the truth, folks. Open inquiry, honest investigation, and acceptance of the line of evidence no matter where it leads.
Researchers at Stanford have observed that foraging harvester ants act like TCP/IP packets, so much so that they're calling the ants' behavior "the anternet".
Transmission Control Protocol, or TCP, is an algorithm that manages data congestion on the Internet, and as such was integral in allowing the early web to scale up from a few dozen nodes to the billions in use today. Here's how it works: As a source, A, transfers a file to a destination, B, the file is broken into numbered packets. When B receives each packet, it sends an acknowledgment, or an ack, to A, that the packet arrived.
This feedback loop allows TCP to run congestion avoidance: If acks return at a slower rate than the data was sent out, that indicates that there is little bandwidth available, and the source throttles data transmission down accordingly. If acks return quickly, the source boosts its transmission speed. The process determines how much bandwidth is available and throttles data transmission accordingly.
It turns out that harvester ants (Pogonomyrmex barbatus) behave nearly the same way when searching for food. Gordon has found that the rate at which harvester ants -- which forage for seeds as individuals -- leave the nest to search for food corresponds to food availability.
A forager won't return to the nest until it finds food. If seeds are plentiful, foragers return faster, and more ants leave the nest to forage. If, however, ants begin returning empty handed, the search is slowed, and perhaps called off.
The reboot of Cosmos has been solid but not spectacular so far, but the second episode contains as solid and clear an explanation of evolution as I've ever seen.
Even if evolution clashes with your world view, this is worth watching if only to understand what you're aligned against (per Bret Victor's advice). The third episode airs on Fox tonight and is about the creation of the scientific method.
I love this video. Love love love. Chao-Lin Kuo surprises Andrei Linde and his wife with the news that gravitational waves were detected, proving Linde's theory of an inflationary universe.
Love love love. (via @stevenstrogatz)
Update: Many people have asked what Kuo is saying to Linde on the doorstep. Let's start with "5 sigma". The statistical measure of standard deviation (represented by the Greek letter sigma) is an indication of how sure scientists are of their results. (It has a more technical meaning than that, but we're not taking a statistics course here.) A "5 sigma" level of standard deviation indicates 99.99994% certainty of the result...or a 0.00006% chance of a statistical fluctuation. That's a 1 in 3.5 million chance. This is the standard particle physicists use for declaring the discovery of a new particle.
The "point-2" is a bit more difficult to explain. Sean Carroll defines r as "the ratio of gravitational waves to density perturbations" as measured by the BICEP2 experiment, the telescope used to make these measurements. What BICEP2 found was an r value of 0.2:
From the brief explanation of the science behind the BICEP2 experiment:
According to the theory of Inflation, the Universe underwent a violent and rapid expansion at only 10^-35 seconds after the Big Bang, making the horizon size much larger, and allowing the space to become flat. Confirmation of Inflation would be an amazing feat in observational Cosmology. Inflation during the first moments of time produced a Cosmic Gravitational-Wave Background (CGB), which in turn imprinted a faint but unique signature in the polarization of the CMB. Since gravitational waves are by nature tensor fluctuations, the polarization signature that the CGB stamps onto the CMB has a curl component (called "B-mode" polarization). In contrast, scalar density fluctuations at the surface of last scattering only contribute a curl-free (or "E-mode") polarization component to the CMB which was first detected by the DASI experiment at the South Pole.
The big deal with BICEP2 is the ability to accurately detect the B-mode polarization for the first time. r is the ratio between these two different types of polarization, E-mode & B-mode. Any result for r > 0 indicates the presence of B-mode polarization, which, according to the theory, was caused by gravitational waves at the time of inflation. So, that's basically what Kuo is on about.
Update: The Atlantic's Megan Garber spoke to Stanford's science information officer about how the video came about.
We didn't do any re-takes. The goal was for it to be a really natural thing. We did ask him to tell us what he was feeling and what the research means. But what you see in the video is just very off-the-cuff and raw. Part of it was, we went there not even knowing if we'd be able to use or keep anything that we did. It was just as likely that he would have been emotional in a way that he didn't want us to share, or that his wife didn't. So we went into it with no guarantee-we knew we'd be able to shoot, but didn't know if we'd be able use it. So we're thankful that they agreed to let us do that.
Finally a viral video that's genuine and not staged or reality TV'd.
This is huge: physicists have detected gravitational waves that harken back to the beginning of the universe, when it was "a trillionth of a trillionth of a trillionth of a second old". The discovery goes a long way toward proving the inflation theory of how the universe formed.
Reaching back across 13.8 billion years to the first sliver of cosmic time with telescopes at the South Pole, a team of astronomers led by John M. Kovac of the Harvard-Smithsonian Center for Astrophysics detected ripples in the fabric of space-time -- so-called gravitational waves -- the signature of a universe being wrenched violently apart when it was roughly a trillionth of a trillionth of a trillionth of a second old. They are the long-sought smoking-gun evidence of inflation, proof, Dr. Kovac and his colleagues say, that Dr. Guth was correct.
Inflation has been the workhorse of cosmology for 35 years, though many, including Dr. Guth, wondered whether it could ever be proved.
If corroborated, Dr. Kovac's work will stand as a landmark in science comparable to the recent discovery of dark energy pushing the universe apart, or of the Big Bang itself. It would open vast realms of time and space and energy to science and speculation.
Confirming inflation would mean that the universe we see, extending 14 billion light-years in space with its hundreds of billions of galaxies, is only an infinitesimal patch in a larger cosmos whose extent, architecture and fate are unknowable. Moreover, beyond our own universe there might be an endless number of other universes bubbling into frothy eternity, like a pot of pasta water boiling over.
If the results are confirmed, Guth will undoubtably win the Nobel in Physics for this soon. Phil Plait at Bad Astronomy has more on the discovery.
Update: This video of Chao-Lin Kuo (one of the principle investigators on this experiment) telling physicist Andrei Linde (a leading inflation theorist) about the result is just outstanding.
Update: Upon further review, it turns out the evidence for the gravitational waves is inconclusive. The problem? Dust on the lens, basically:
The problem comes in when the astronomers looked at things that might mimic the signal they were looking for. For example, dust (long, complex carbon-molecules that are much like fireplace soot) floating in space can look very much like the signal BICEP2 was seeking. The astronomers knew this, and used data from the ESA mission Planck to investigate it. Planck measured the amount of dust lying along the direction BICEP2 was looking, and the astronomers concluded the amount of dust in their line-of-sight was low. The signal they saw, therefore, must be from inflation.
And here's the bummer part: They were using preliminary Planck data. When better data from Planck were released, the astronomers used that, and found that the amount of galactic dust in their view was much higher than they previously thought. That weakens their case considerably.
I don't want to see the video of someone telling Linde "whoops!"