kottke.org posts about science
Sam Arbesman has turned his mesofacts concept into an upcoming book called The Half-Life of Facts.
Facts change all the time. The age at which women should get a mammogram has increased. Smoking has gone from doctor recommended to deadly while the healthiness of carbs and fat seems to be in constant flux. We used to think the Earth was the center of the universe, that Pluto was a planet, and that the brontosaurus was a real dinosaur. What we know about the world is constantly changing.
Samuel Arbesman is an expert in scientometrics, literally the science of science-how we know what we know. It turns out that knowledge in most fields evolves in systematic and predictable ways, and understanding that evolution can be enormously powerful. For instance, knowing how different branches of medicine overturn their bodies of knowledge can improve the way we train (and retrain) physicians.
The Half-Life of Facts features fascinating examples from fields as diverse as technology and literature. It will help us find new ways to measure the world while accepting the limits of how much we can know with certainty.
Back in 1999, as he prepared to make a movie called The Minority Report, Steven Spielberg gathered top science and technology types to an “idea summit” where they would share thoughts on what things might look like in 50 years. To mark the ten year anniversary of the movie’s release, Wired asked a dozen of the summit attendees to reflect on the experience. According to one participant: “There was no shortage of megalomania, although there was good reason for it.”
In this series of slow motion clips, you can see that if you hold a Slinky by one end and drop it, the bottom end doesn’t actually move until the top end catches up with it.
I’ve watched this like six times and it drops my jaw every time…the bottom of the Slinky JUST. DOES. NOT. MOVE. Here’s the scientific explanation:
The explanation that “it takes time for the bottom of the slinky to feel the change” might work ok, but it isn’t the best.
Then why doesn’t the bottom of the slinky fall as the top is let go? I think the best thing is to think of the slinky as a system. When it is let get, the center of mass certainly accelerates downward (like any falling object). However, at the same time, the slinky (spring) is compressing to its relaxed length. This means that top and bottom are accelerating towards the center of mass of the slinky at the same time the center of mass is accelerating downward.
(via @stevenstrogatz)
Update: See also The Physics of a Falling Slinky. (via @jeffhellman)
When they were launched in 1977, the two Voyager spacecraft each carried with them a 12-inch gold-plated copper record containing multimedia pertaining to life on Earth, the idea being that if an extraterrestrial ran across one of these records millions of years from now, they could play it an learn something about our planet. This site has a listing of some of the music, images, and sounds contained on the records. Here are two of the images included…the first is a rudimentary mathematics primer and the second is a family portrait:
I wonder when we’ll see these records again. I mean, it seems more plausible that Elon Musk’s grandson will mount an expedition to retrieve a Voyager probe in 2077 than some alien running across the thing.
From The Royal Observatory, Greenwich, a short video explanation of how scientists measure the size of the Universe.
This is science for the layperson done right…PBS or the Discovery Channel would have inflated this into a 30-minute show. (via ★interesting)
Venus passed in front of the Sun yesterday for the last time until 2117. The transit took almost seven hours but this NASA video shows it in under a minute.
The Tacoma Narrows Bridge was open for about four months in 1940 before a steady wind set it twisting and ultimately tore the bridge apart.
Damn Interesting has a detailed account of the bridge’s short history and demise.
After opening, the new bridge shortly came to be known as “Galloping Gertie,” so named by white-knuckled motorists who braved the writhing bridge on windy days. Even in a light breeze, Gertie’s undulations were known to produce waves up to ten feet tall. Sometimes these occurrences were brief, and other times they lasted for hours at a time. Numerous travelers shunned the route altogether to avoid becoming seasick, whereas many thrill-seeking souls paid the 75-cent toll to traverse Gertie during her more spirited episodes.
The 99% Invisible podcast devoted a show to the collapse of the bridge.
(via sarah pavis)
According to a recent study, the cause of Pine Mouth (where eating pine nuts can make food taste horrible for days afterwards) is still unknown. The full text of the study is behind a paywall but The Awl has a short summary of the findings.
Now, a new publication by the Journal of Agricultural & Food Chemistry finds esteemed scientists literally throwing up their hands. They learned a lot about pine nuts and their composition! But nothing useful.
cc: Megnut.
The Jenny McCarthy Body Count site tracks the number of vaccine-preventable illnesses and deaths in the US since June 2007.
In June 2007 Jenny McCarthy began promoting anti-vaccination rhetoric. Because of her celebrity status she has appeared on several television shows and has published multiple books advising parents not to vaccinate their children. This has led to an increase in the number of vaccine preventable illnesses as well as an increase in the number of vaccine preventable deaths.
I hadn’t realized just how much of a nutter McCarthy is…her embrace of pseudoscience runs deep.
Indigo children is a term used to describe children who are believed to possess special, unusual and sometimes supernatural traits or abilities. The term is pseudoscientific. The idea is based on New Age concepts developed in the 1970s by Nancy Ann Tappe and further developed by Jan Tober and Lee Carroll. The concept of indigo children gained popular interest with the publication of a series of books in the late 1990s and the release of several films in the following decade. A variety of books, conferences and related materials have been created surrounding belief in the idea of indigo children and their nature and abilities. The interpretations of these beliefs range from their being the next stage in human evolution, in some cases possessing paranormal abilities such as telepathy, to the belief that they are more empathic and creative than their peers.
I missed this last July when the news came out, but since I’ve been following the Pioneer Anomaly for the past eight years, I wanted to mention it here for closure purposes. First, what the hell is the Pioneer Anomaly?
The Pioneer anomaly or Pioneer effect is the observed deviation from predicted accelerations of the Pioneer 10 and Pioneer 11 spacecraft after they passed about 20 astronomical units (3×10^9 km; 2×10^9 mi) on their trajectories out of the Solar System. Both Pioneer spacecraft are escaping the Solar System, but are slowing under the influence of the Sun’s gravity. Upon very close examination of navigational data, the spacecraft were found to be slowing slightly more than expected. The effect is an extremely small but unexplained acceleration towards the Sun, of 8.74±1.33x10^-10 m/s^2.
A team at JPL has tracked the problem to uneven heat emissions from the probes’ fuel source.
For their new analysis, Turyshev et. al. compiled a lot more data than had ever been analyzed before, spanning a much longer period of the Pioneers’ flight times. They studied 23 years of data from Pioneer 10 instead of just 11, and 11 years of data from Pioneer 11 instead of 3. As explained in their new paper, the more complete data sets reveal that the spacecraft’s anomalous acceleration did indeed seem to decrease with time. In short, the undying force had been dying after all, just like the decaying plutonium.
A more recent paper by the same researchers offers even more support for their theory. Case closed, I say.
Aisha Mustafa, a 19-year-old Egyptian physics student, has invented a promising new quantum propulsion system for spacecraft.
Mustafa invented a way of tapping this quantum effect via what’s known as the dynamic Casimir effect. This uses a “moving mirror” cavity, where two very reflective very flat plates are held close together, and then moved slightly to interact with the quantum particle sea. It’s horribly technical, but the end result is that Mustafa’s use of shaped silicon plates similar to those used in solar power cells results in a net force being delivered. A force, of course, means a push or a pull and in space this equates to a drive or engine.
Soon after the US dropped two nuclear bomb on Japan in 1945, a group of physicists at the University of Pennsylvania decided to investigate for themselves how nuclear fission and the bomb might work using non-classified materials. In doing so, they ventured into classified territory and raised questions about the nature of science and secrecy.
To what degree would nuclear research become shackled by the requirements of national security? Would the open circulation of new scientific knowledge cease if that knowledge was relevant to nuclear fission? Those questions were hardly idle speculation: From the fall of 1945 through the summer of 1946, the US Congress was crafting new, unprecedented legislation that would legally define the bounds of open scientific research and even free speech. The idea of restricting open scientific communication “may seem drastic and far-reaching,” President Harry S. Truman argued in an October 1945 statement exhorting Congress to rapid action. But, he said, the atomic bomb “involves forces of nature too dangerous to fit into any of our usual concepts.”
The former Manhattan Project scientists who founded what would eventually become the Federation of American Scientists were adamantly opposed to keeping nuclear technology a closed field. From early on they argued that there was, as they put it, “no secret to be kept.” Attempting to control the spread of nuclear weapons by controlling scientific information would be fruitless: Soviet scientists were just as capable as US scientists when it came to discovering the truths of the physical world. The best that secrecy could hope to do would be to slightly impede the work of another nuclear power. Whatever time was bought by such impediment, they argued, would come at a steep price in US scientific productivity, because science required open lines of communication to flourish.
At the University of Pennsylvania were nine scientists sympathetic to that message. All had been involved with wartime work, but in the area of radar, not the bomb. Because they had not been part of the Manhattan Project in any way, they were under no legal obligation to maintain secrecy; they were simply informed private citizens. In the fall of 1945, they tried to figure out the technical details behind the bomb.
Dr. Sergio Cittolin has worked at CERN for the past 30 years as a research physicist. He has also made several drawings of the Large Hadron Collider in the style of Leonardo da Vinci.
Symmetry magazine profiled Cittolin a few years ago.
As a naturalist, da Vinci probed, prodded, and tested his way to a deeper understanding of how organisms work and why, often dissecting his object of study with this aim. “I thought, why not present the idea of data analysis to the world within the naturalist world of Leonardo?” Cittolin says. In the drawing below, the CMS detector is the organism to be opened; the particles passing through it and the tracks they leave behind are organs exposed for further investigation.
Cittolin brings a sense of humor to his work. For example, after betting CMS colleague Ariella Cattai that he could produce a quality drawing for the cover of the CMS tracker technical proposal by a given deadline, he included in the drawing a secret message in mirror-image writing-which was also a favorite of da Vinci’s. The message jokingly demanded a particular reward for his hard work. The completed picture was delivered on time and within a few hours Cattai cleverly spotted and deciphered the message. She promptly presented him with the requested bottle of wine.
(via ★johnpavlus)
Up until 2007, Kodak operated a small nuclear reactor that contained 3.5 pounds of weapons-grade highly enriched uranium.
The Democrat and Chronicle learned of the facility when an employee happened to mention it to a reporter a few months ago.
The recent silence was by design. Detailed information about nuclear power plants and other entities with radioactive material has been restricted since the 2001 terrorist attacks.
Nuclear non-proliferation experts express surprise that an industrial manufacturer like Eastman Kodak had had weapons-grade uranium, especially in a post-9/11 world.
“I’ve never heard of it at Kodak,” said Miles Pomper, senior research associate at the Center for Nonproliferation Studies in Washington. “It’s such an odd situation because private companies just don’t have this material.”
(via @kdawson)
In studying yogurt’s effects on obesity in mice, a team of MIT scientists discovered several unanticipated results. Basically, yogurt turned these mice into Kanye. Science is weird.
First, the scientists noticed that the yogurt-eating mice were incredibly shiny. Using both traditional histology techniques and cosmetic rating scales, the researchers showed that these animals had 10 times the active follicle density of other mice, resulting in luxuriantly silky fur.
Then the researchers spotted something particular about the males: they projected their testes outward, which endowed them with a certain “mouse swagger,” Erdman says. On measuring the males, they found that the testicles of the yogurt consumers were about 5 percent heavier than those of mice fed typical diets alone and around 15 percent heavier than those of junk-eating males.
More important, that masculinity pays off. In mating experiments, yogurt-eating males inseminated their partners faster and produced more offspring than control mice. Conversely, females that ate the yogurt diets gave birth to larger litters and weaned those pups with greater success. Reflecting on their unpublished results, Erdman and Alm think that the probiotic microbes in the yogurt help to make the animals leaner and healthier, which indirectly improves sexual machismo.
‘Mouse swagger’
Update: Illustration by Chris Piascik.
George Dvorsky details five possible scientific explanations for Westeros’ seasons of unpredictable length. A “wobbly planetary tilt” is one possible reason:
In the episode “The Kingsroad,” we learn that Westeros has at least one moon. It’s very possible, therefore, that they have a very small or distant moon, that is causing a variable tilt in their planet’s rotational axis.
It’s interesting to note that, according to legend, Westeros used to have two moons, but “one wandered too close to the sun and it cracked from the heat” pouring out a thousand thousand dragons. Well, dragons aside, it’s conceivable that some kind of cataclysmic celestial event could have wiped out their second moon, which would have thrown their planet’s rotational axis out of whack.
In a review of the Color Uncovered iPad app, Carl Zimmer highlights something I hadn’t heard before: Claude Monet could see in ultraviolet.
Late in his life, Claude Monet developed cataracts. As his lenses degraded, they blocked parts of the visible spectrum, and the colors he perceived grew muddy. Monet’s cataracts left him struggling to paint; he complained to friends that he felt as if he saw everything in a fog. After years of failed treatments, he agreed at age 82 to have the lens of his left eye completely removed. Light could now stream through the opening unimpeded. Monet could now see familiar colors again. And he could also see colors he had never seen before. Monet began to see — and to paint — in ultraviolet.
The condition is called aphakia.
They appear to be, although not in a way that we think of as intelligence sometimes. Fascinating article.
Octopuses have the largest brains of any invertebrate. Athena’s is the size of a walnut — as big as the brain of the famous African gray parrot, Alex, who learned to use more than one hundred spoken words meaningfully. That’s proportionally bigger than the brains of most of the largest dinosaurs.
Another measure of intelligence: you can count neurons. The common octopus has about 130 million of them in its brain. A human has 100 billion. But this is where things get weird. Three-fifths of an octopus’s neurons are not in the brain; they’re in its arms.
“It is as if each arm has a mind of its own,” says Peter Godfrey-Smith, a diver, professor of philosophy at the Graduate Center of the City University of New York, and an admirer of octopuses. For example, researchers who cut off an octopus’s arm (which the octopus can regrow) discovered that not only does the arm crawl away on its own, but if the arm meets a food item, it seizes it — and tries to pass it to where the mouth would be if the arm were still connected to its body.
“Meeting an octopus,” writes Godfrey-Smith, “is like meeting an intelligent alien.” Their intelligence sometimes even involves changing colors and shapes. One video online shows a mimic octopus alternately morphing into a flatfish, several sea snakes, and a lionfish by changing color, altering the texture of its skin, and shifting the position of its body. Another video shows an octopus materializing from a clump of algae. Its skin exactly matches the algae from which it seems to bloom-until it swims away.
George Dvorsky argues that if we wanted to, humanity could get a Dyson sphere up and running in a few decades.
The Dyson sphere, also referred to as a Dyson shell, is the brainchild of the physicist and astronomer Freeman Dyson. In 1959 he put out a two page paper titled, “Search for Artificial Stellar Sources of Infrared Radiation” in which he described a way for an advanced civilization to utilize all of the energy radiated by their sun. This hypothetical megastructure, as envisaged by Dyson, would be the size of a planetary orbit and consist of a shell of solar collectors (or habitats) around the star. With this model, all (or at least a significant amount) of the energy would hit a receiving surface where it can be used. He speculated that such structures would be the logical consequence of the long-term survival and escalating energy needs of a technological civilization.
Needless to say, the amount of energy that could be extracted in this way is mind-boggling. According to Anders Sandberg, an expert on exploratory engineering, a Dyson sphere in our solar system with a radius of one AU would have a surface area of at least 2.72x1017 km2, which is around 600 million times the surface area of the Earth. The sun has an energy output of around 4x1026 W, of which most would be available to do useful work.
The downside: we’d have to part with Mercury to do it.
And yes, you read that right: we’re going to have to mine materials from Mercury. Actually, we’ll likely have to take the whole planet apart. The Dyson sphere will require a horrendous amount of material-so much so, in fact, that, should we want to completely envelope the sun, we are going to have to disassemble not just Mercury, but Venus, some of the outer planets, and any nearby asteroids as well.
At Forbes, Alex Knapp explains why Dvorsky’s scheme and timeline might not work.
I emailed Astronomer Phil Plait about this project, who told me in no uncertain terms that the project doesn’t make sense.
“Dismantling Mercury, just to start, will take 2 x 10^30 Joules, or an amount of energy 100 billion times the US annual energy consumption,” he said. “[Dvorsky] kinda glosses over that point. And how long until his solar collectors gather that much energy back, and we’re in the black?”
Now available in its entirety on YouTube, a 95-minute documentary on physicist Richard Feynman called No Ordinary Genius.
The excellent film on Andrew Wiles’ search for the solution to Fermat’s Last Theorem is available as well (watch the first two minutes and you’ll be hooked).
A pair of recent info visualizations look as though they were painted by Vincent van Gogh. Wind Map shows the realtime flow of wind over the United States.
Perpetual Ocean is a NASA animation of ocean currents around the world.
Would be cool to see both of these rendered through Stamen’s watercolor filter.
With their ability to move seamlessly through walls, rocks, lead shielding, and entire planets, neutrinos would seem like a great choice for a new method of wireless communication. Scientists at Fermilab have demonstrated sending messages via neutrino but the downside is that the slippery particles can also move seamlessly through detectors.
In the Fermilab experiment, the physicists fired a proton beam into a carbon target to produce a shower of particles called pions and kaons that quickly decay into neutrinos. For every pulse of 22.5 trillion protons, the physicists registered an average of 0.81 neutrino with the 170-ton MINERvA detector.
That translates into a data rate of 0.1 bits/second, or just slightly faster than America Online’s dialup service circa 1992. (Hey, hey, if you liked that one, perhaps you’ll also enjoy my impression of Dana Carvey doing George H.W. Bush.)
The VISTA telescope in Chile recently took a photo of the sky that contains over 200,000 galaxies. For reference, the Hubble Ultra-Deep Field image shows only about 10,000 galaxies (but sees further back in time, I think).
I’ve spent years studying all this, and it still sometimes gets to me: just how flipping BIG the Universe is! And this picture is still just a tiny piece of it: it’s 1.2 x 1.5 degrees in size, which means it’s only 0.004% of the sky! And it’s not even complete: more observations of this region are planned, allowing astronomers to see even deeper yet.
Here’s a full view of the image that looks sorta unimpressive:
You can download the original 17,000 x 11,000 pixel image here (250 Mb, yo) for the full effect. As a preview, this is several levels of zoom in…just a tiny part of the full image.
Birds can detect the magnetic field of the Earth, which gives them an incredible sense of direction. Curiously, this sense of direction doesn’t work in darkness. This led scientists to discover that some birds can actually see the directions overlaid on their normal vision, like a heads-up display.
According to the new model, when a photon of light from the Sun is absorbed by a special molecule in the bird’s eye, it can cause an electron to be kicked from its normal state into an alternative location a few nanometres away. Until the electron eventually relaxes back, it creates an ‘electric dipole field’ which can augment the bird’s vision - for example altering colours or brightness.
Crucially, the alignment of the molecule compared to the Earth’s magnetic field controls the time it takes for the electron to relax back, and so controls the strength of the effect on the bird’s vision.
There are many such molecules spread throughout the eye, with different orientations. So from the patterns on top of its vision, and the change of these patterns as it moves its head, the bird learns about the direction of Earth’s magnetic field.
(via @daveg)
The NY Times is reporting that a data bump “smells like the Higgs boson”. The odor is emanating not from CERN in Europe but from Fermilab near Chicago, where their Tevatron still flings some pretty fast particles.
“Based on the current Tevatron data and results compiled through December 2011 by other experiments, this is the strongest hint of the existence of a Higgs boson,” said the report, which will be presented on Wednesday by Wade Fisher of Michigan State University to a physics conference in La Thuile, Italy.
None of these results, either singly or collectively, are strong enough for scientists to claim victory. But the recent run of reports has encouraged them to think that the elusive particle, which is the key to mass and diversity in the universe, is within sight, perhaps as soon as this summer.
Update: The Tevatron is no longer flinging, having been shut down in 2011 due to budget cuts. Which makes the Higgs discovery a little bittersweet, to say the least. (thx, miles)
Remember those time traveling neutrinos that they found in Italy? It is likely that a faulty connection between the GPS and the computer collecting data is to blame for the time travel illusion.
According to sources familiar with the experiment, the 60 nanoseconds discrepancy appears to come from a bad connection between a fiber optic cable that connects to the GPS receiver used to correct the timing of the neutrinos’ flight and an electronic card in a computer. After tightening the connection and then measuring the time it takes data to travel the length of the fiber, researchers found that the data arrive 60 nanoseconds earlier than assumed.
Neutrinos? More like Nintendo…they forgot to blow in the cartridge. (via @tcarmody)
There is increasing evidence that a parasite called Toxoplasma gondii, which many humans have gotten from cat feces, can rewire our brains and modify human behavior in unexpected ways.
The parasite, which is excreted by cats in their feces, is called Toxoplasma gondii (T. gondii or Toxo for short) and is the microbe that causes toxoplasmosis-the reason pregnant women are told to avoid cats’ litter boxes. Since the 1920s, doctors have recognized that a woman who becomes infected during pregnancy can transmit the disease to the fetus, in some cases resulting in severe brain damage or death. T. gondii is also a major threat to people with weakened immunity: in the early days of the AIDS epidemic, before good antiretroviral drugs were developed, it was to blame for the dementia that afflicted many patients at the disease’s end stage. Healthy children and adults, however, usually experience nothing worse than brief flu-like symptoms before quickly fighting off the protozoan, which thereafter lies dormant inside brain cells-or at least that’s the standard medical wisdom.
But if Flegr is right, the “latent” parasite may be quietly tweaking the connections between our neurons, changing our response to frightening situations, our trust in others, how outgoing we are, and even our preference for certain scents. And that’s not all. He also believes that the organism contributes to car crashes, suicides, and mental disorders such as schizophrenia. When you add up all the different ways it can harm us, says Flegr, “Toxoplasma might even kill as many people as malaria, or at least a million people a year.”
The Scale of the Universe 2 is an interactive Powers of Ten that takes you from the Planck length all the way up to the size of the observable Universe. That’s more than 60 orders of magnitude! Also interesting that the smallest things (Planck length, strings, branes) are millions of times smaller compared to human scale than the observable Universe is larger. Plenty of room at the bottom indeed.
In this transcript of a talk given to the attendees of the Joint Summits on Translational Science, Carl Zimmer highlights an important aspect of understanding the human body and how to treat its many maladies: the ecosystem of microbes.
The microbes in your body at this moment outnumber your cells by ten to one. And they come in a huge diversity of species — somewhere in the thousands, although no one has a precise count yet. By some estimates there are twenty million microbial genes in your body: about a thousand times more than the 20,000 protein-coding genes in the human genome. So the Human Genome Project was, at best, a nice start. If we really want to understand all the genes in the human body, we have a long way to go.
Now you could say “Who cares? They’re just wee animalcules.” Those wee animacules are worth caring about for many reasons. One of the most practical of those reasons is that they have a huge impact on our “own” health. Our collection of microbes-the microbiome-is like an extra organ of the human body. And while an organ like the heart has only one function, the microbiome has many.
When food comes into the gut, for example, microbes break some of them down using enzymes we lack. Sometimes the microbes and our own cells have an intimate volley, in which bacteria break down a molecule part way, our cells break it down some more, the bacteria break it down even more, and then finally we get something to eat.
Another thing that the microbiome does is manage the immune system. Certain species of resident bacteria, like Bacteroides fragilis, produce proteins that tamp down inflammation. When scientists rear mice that don’t have any germs at all, they have a very difficult time developing a normal immune system. The microbiome has to tutor the immune system in how to do its job properly. It also acts like an immune system of its own, fighting off invading microbes, and helping to heal wounds.
While the microbiome may be an important organ, it’s a peculiar one. It’s not one solid hunk of flesh. It’s an ecosystem, made up of thousands of interacting species.
Scott Carpenter was one of the original seven Mercury astronauts and the second American to orbit the Earth. Just before he went into space, his father wrote this wonderful letter.
And I venture to predict that after all the huzzas have been uttered and the public acclaim is but a memory, you will derive the greatest satisfaction from the serene knowledge that you have discovered new truths. You can say to yourself: this I saw, this I experienced, this I know to be the truth. This experience is a precious thing; it is known to all researchers, in whatever field of endeavour, who have ventured into the unknown and have discovered new truths.
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