kottke.org posts about science
A list of ten things that you didn’t know about the earth. My favorite one, by far:
But what if you did dig a hole through the Earth and jump in? What would happen?
Well, you’d die (see below). But if you had some magic material coating the walls of your 13,000 km deep well, you’d have quite a trip. You’d accelerate all the way down to the center, taking about 20 minutes to get there. Then, when you passed the center, you’d start falling up for another 20 minutes, slowing the whole way. You’d just reach the surface, then you’d fall again. Assuming you evacuated the air and compensated for Coriolis forces, you’d repeat the trip over and over again, much to your enjoyment and/or terror. Actually, this would go on forever, with you bouncing up and down. I hope you remember to pack a lunch.
Note that as you fell, you accelerate all the way down, but the acceleration itself would decrease as you fell: there is less mass between you and the center of the Earth as you head down, so the acceleration due to gravity decreases as you approach the center. However, the speed with which you pass the center is considerable: about 7.7 km/sec (5 miles/second).
Fast forward to the year 2483 and we’ll probably all be using such holes to quickly travel through the earth. Spain to New Zealand in 42 minutes! New York to the middle of the Indian Ocean? 42 minutes! I also recall reading somewhere that the tunnels don’t need to run through the middle of the earth. You don’t get the free fall effect, but with the proper contraption (mag-lev tunnel train?) you’ll be pulled through the tunnel at a great speed. Does this ring anyone’s bell?
Update: A bell has rung. The tunnels described above are called chord tunnels and the travel time through the earth in a frictionless chord tunnel is always 42 minutes, even if the tunnel is only a few hundred miles long or so (say from New York to Detroit). (thx, mike)
Update: In this short Nova clip, Neil deGrasse Tyson “demonstrates” a trip through the center of the earth. (thx, michael)
Steven Johnson’s new book is called The Invention of Air.
It has an organizing theme of how innovative ideas emerge and spread in a society, while integrating many different threads along the way: 18th-century London coffeehouse culture; the Adams-Jefferson letters; the origins of ecosystem science; the giant dragonflies of the Carboniferous Era; the impact of energy deposits on British political change; the discovery of the gulf stream; the Alien and Sedition acts; Jefferson’s bible; the Lunar Society; mob violence; Thomas Kuhn’s Structure of Scientific Revolutions; Ben Franklin’s kite experiment.
It’s also not, somehow, 6500 pages. I thought for sure that this was going to be some sort of long zoom book, not a book with a long zoom approach.
Jonah Lerher on daydreaming and the human brain’s default network. Creativity, especially with regard to children, might be stifled by too little daydreaming and too much television.
After monitoring the daily schedule of the children for several months, Belton came to the conclusion that their lack of imagination was, at least in part, caused by the absence of “empty time,” or periods without any activity or sensory stimulation. She noticed that as soon as these children got even a little bit bored, they simply turned on the television: the moving images kept their minds occupied. “It was a very automatic reaction,” she says. “Television was what they did when they didn’t know what else to do.”
The problem with this habit, Belton says, is that it kept the kids from daydreaming. Because the children were rarely bored — at least, when a television was nearby — they never learned how to use their own imagination as a form of entertainment. “The capacity to daydream enables a person to fill empty time with an enjoyable activity that can be carried on anywhere,” Belton says. “But that’s a skill that requires real practice. Too many kids never get the practice.”
But television isn’t the default network that Lehrer is referring to:
Every time we slip effortlessly into a daydream, a distinct pattern of brain areas is activated, which is known as the default network. Studies show that this network is most engaged when people are performing tasks that require little conscious attention, such as routine driving on the highway or reading a tedious text. Although such mental trances are often seen as a sign of lethargy — we are staring haplessly into space — the cortex is actually very active during this default state, as numerous brain regions interact. Instead of responding to the outside world, the brain starts to contemplate its internal landscape. This is when new and creative connections are made between seemingly unrelated ideas.
Basketball players are more skilled than even keen observers of the game (sportswriters and coaches) when predicting whether a shot will go in the basket or not.
Not surprisingly, the players were significantly better at predicting whether or not the shot would go in. While they got it right more than two-thirds of the time, the non-playing experts (i.e., the coaches and writers) only got it right 44 percent of the time.
It’s thought that the brains of the players act as though they are actually taking the shot.
In other words, when professional basketball players watch another player take a shot, mirror neurons in their pre-motor areas might light up as if they were taking the same shot. This automatic empathy allows them to predict where the ball will end up before the ball is even in the air.
Before European conquerers arrived, large areas of the Amazon River basin had been cleared away to make room for a network of towns and villages.
The findings raise big questions, says Susanna Hecht of the University of California in Los Angeles.
For starters, it forces a rethink of the long-held assumption that these parts of the Amazon were virtually empty before colonisation. What’s more, it shows that the large populations that did inhabit the region transformed the landscape.
“What we find is that what we think of as the primitive Amazon forest is not so primitive after all,” Heckenberger told New Scientist. “European colonialism wasted huge numbers of native peoples and cleared them off the land, so that the forest returned.”
I’m gonna plug 1491 again…the story above isn’t news to anyone who’s read this book, which argues that there was plenty going on in the New World before Columbus, et. al. arrived.
Ice cream is an igneous rock made up of ice, air, and sugar.
Much like igneous rocks, the same liquid mix can turn out very differently depending on what happens while it is freezing. The goal of most ice cream and sorbet is to have a smooth and creamy texture, which would be ruined by the presence of large ice crystals. To achieve this, you want to cool your ice cream so quickly that the crystals don’t have time to grow, and keep the mixture stirred up while it freezes. There’s a lot of energy involved in the transition from liquid to solid water, and a home ice cream maker can’t do the heat transfer quickly enough to keep the ice crystals small, so you have to sit there and turn the crank until your arm is sore while the mixture slowly freezes (or invest in a fancier machine that will do the stirring for you).
See also what happens when ice cream sits for too long in the freezer and the book, The Science of Ice Cream.
The Seed Salon features videos and text transcripts of conversations with scientists and other persons of scientific interest. Includes the likes of Paola Antonelli, Noam Chomsky, Errol Morris, and Lisa Randall.
Every now and then, you may find yourself wondering: how many atoms of Jesus do you eat everyday?
In the Catholic doctrine of transubstantiation, the eucharist actually becomes the blood and body of Jesus Christ. […] Transubstantiation means that eventually the earth’s entire biomass will be made out of Jesus.
Eventually = 4.91 billion years.
In a Swiss experiment, two entangled photons 18 km away from each other were able to communicate with each other almost instantaneously.
On the basis of their measurements, the team concluded that if the photons had communicated, they must have done so at least 100,000 times faster than the speed of light — something nearly all physicists thought would be impossible. In other words, these photons cannot know about each other through any sort of normal exchange of information.
Update: Hrm, the link above scampered behind Nature’s paywall. Here’s a post on the Scientific American blog instead.
Flat-earthers are people who believe, here in the 21st century, that the Earth is flat. (Believers in a round earth are called globularists.)
And what about the fact that no one has ever fallen off the edge of our supposedly disc-shaped world? Mr McIntyre laughs. “This is perhaps one of the most commonly asked questions,” he says. “A cursory examination of a flat earth map fairly well explains the reason — the North Pole is central, and Antarctica comprises the entire circumference of the Earth. Circumnavigation is a case of travelling in a very broad circle across the surface of the Earth.”
If, like me, you have questions about how the Earth could possibly be flat, some of them are answered in the Flat Earth FAQ.
Q: “What about the stars, sun and moon and other planets? Are they flat too? What are they made of?”
A: The sun and moon, each 32 miles in diameter, circle Earth at a height of 3000 miles at its equator, located midway between the North Pole and the ice wall. Each functions similar to a “spotlight,” with the sun radiating “hot light,” the moon “cold light.” As they are spotlights, they only give light out over a certain are which explains why some parts of the Earth are dark when others are light. Their apparent rising and setting are caused by optical illusions. In the “accelerating upwards” model, the stars, sun and moon are also accelerating upwards. The stars are about as far as San Francisco is from Boston. (3100 miles)
BTW, the “ice wall” is what separates the edge of the earth’s disc with outer space or whatever ether or monsters are beyond the earth. We know the wall as Antarctica. I call shenanigans on all this…it’s gotta be a hoax. Nobody’s this ignorant, right? Please?
I’ve been waiting patiently for this one. Big Picture has 27 photos of the Large Hadron Collider and they’re stunning. The scale of this thing, it’s overwhelming.
Human activities can trigger natural disasters such as earthquakes and flooding.
“Dams are the most dangerous man-made structure likely to cause quake,” says David Booth of the British Geological Survey. By artificially holding a large volume of water in one place, dams increase pressure on fractures beneath the surface of the earth. What’s more, water has a lubricating effect, making it easier for the fractures — or faults — to slip.
Jonah Lerher, author of Proust Was a Neuroscientist, has a piece in the New Yorker this week (not online1) about how the process of insight works in the brain. The main takeaway is that insight comes easiest when our brains are relaxed and not focused on too much detail so that it is able to look for more general associations between seemingly disparate ideas.
Kounios tells a story about an expert Zen meditator who took part in one of the C.R.A. insight experiments. At first, the meditator couldn’t solve any of the insight problems. “This Zen guy went through thirty or so of the verbal puzzles and just drew a blank,” Kounios said. “He was used to being very focussed, but you can’t solve these problems if you’re too focussed.” Then, just as he was about to give up, he started solving one puzzle after another, until, by the end of the experiment, he was getting them all right. It was an unprecedented streak. “Normally, people don’t get better as the task goes along,” Kounios said. “If anything, they get a little bored.” Kounios believes that the dramatic improvement of the Zen meditator came from his paradoxical ability to focus on not being focussed, so that he could pay attention to those remote associations in the right hemisphere. “He had the cognitive control to let go,” Kounios said. “He became an insight machine.”
[1] There’s a samizdat PDF of the article here. ↩
If physical theories were women.
Quantum mechanics is the girl you meet at the poetry reading. Everyone thinks she’s really interesting and people you don’t know are obsessed about her. You go out. It turns out that she’s pretty complicated and has some issues. Later, after you’ve broken up, you wonder if her aura of mystery is actually just confusion.
Would like to see the list for men as well. (via snarkmarket)
Seed Magazine has posted Noah Kalina’s photos of science labs at night. The Salk Institute is represented of course.
The Periodic Table of Videos is a collection of videos about all the elements. All your favorites are there…Neon, Rubidium, Lead, Plutonium.
Physicists of the 20th Century on Banknotes (5 MB PDF), including Marie & Pierre Curie on a short-lived 500 franc note, Niels Bohr on a Danish 500 kroner note, and Nikola Tesla on several notes from Yugoslavia and Serbia. The author of the article is Steve Feller, physics professor at Coe College and my college advisor. Feller has a keen interest in numismatics and recently published a book about the money used in WWII camps.
Humans are consuming natural resources so quickly that we’re running out of elements.
The element gallium is in very short supply and the world may well run out of it in just a few years. Indium is threatened too, says Armin Reller, a materials chemist at Germany’s University of Augsburg. He estimates that our planet’s stock of indium will last no more than another decade. All the hafnium will be gone by 2017 also, and another twenty years will see the extinction of zinc. Even copper is an endangered item, since worldwide demand for it is likely to exceed available supplies by the end of the present century.
Many of the elements listed above are used in the construction of computer equipment and flat-panel TVs.
Scientists were recently “astonished” to find water in Mercury’s atmosphere. Plus, the particles in the atmosphere were blasted off the surface by the solar wind so the atmospheric water could indicate that it can be found on the surface as well. First Mars and now this. Has The Onion done a “Scientists find evidence of water on Earth” story yet?
I try not to miss any of Atul Gawande’s New Yorker articles, but his piece on itching from this week’s issue is possibly the most interesting thing I’ve read in the magazine in a long time. He begins by focusing on a specific patient for whom compulsive itching has become a very serious problem. (Warning, this quote is pretty disturbing…but don’t let it deter you from reading the article.)
…the itching was so torturous, and the area so numb, that her scratching began to go through the skin. At a later office visit, her doctor found a silver-dollar-size patch of scalp where skin had been replaced by scab. M. tried bandaging her head, wearing caps to bed. But her fingernails would always find a way to her flesh, especially while she slept.
One morning, after she was awakened by her bedside alarm, she sat up and, she recalled, “this fluid came down my face, this greenish liquid.” She pressed a square of gauze to her head and went to see her doctor again. M. showed the doctor the fluid on the dressing. The doctor looked closely at the wound. She shined a light on it and in M.’s eyes. Then she walked out of the room and called an ambulance. Only in the Emergency Department at Massachusetts General Hospital, after the doctors started swarming, and one told her she needed surgery now, did M. learn what had happened. She had scratched through her skull during the night — and all the way into her brain.
From there, Gawande pulls out to tell us about itching/scratching (the two are inseparable), then about a recent theory of how our brains perceive the world (“visual perception is more than ninety per cent memory and less than ten per cent sensory nerve signals”), and finally about a fascinating therapy initially developed for those who experience phantom limb pain called mirror treatment.
Among them is an experiment that Ramachandran performed with volunteers who had phantom pain in an amputated arm. They put their surviving arm through a hole in the side of a box with a mirror inside, so that, peering through the open top, they would see their arm and its mirror image, as if they had two arms. Ramachandran then asked them to move both their intact arm and, in their mind, their phantom arm-to pretend that they were conducting an orchestra, say. The patients had the sense that they had two arms again. Even though they knew it was an illusion, it provided immediate relief. People who for years had been unable to unclench their phantom fist suddenly felt their hand open; phantom arms in painfully contorted positions could relax. With daily use of the mirror box over weeks, patients sensed their phantom limbs actually shrink into their stumps and, in several instances, completely vanish. Researchers at Walter Reed Army Medical Center recently published the results of a randomized trial of mirror therapy for soldiers with phantom-limb pain, showing dramatic success.
Crazy! Gawande documents and speculates about other applications of this treatment, including using virtual reality representations instead of mirrors and utilizing multiple mirrors for treatment of M.’s itchy scalp. Anyway, read the whole thing…highly recommended.
About 2 hours ago, the Mars Phoenix rover twittered that it had found evidence of ice on Mars.
Are you ready to celebrate? Well, get ready: We have ICE!!!!! Yes, ICE, *WATER ICE* on Mars! w00t!!! Best day ever!!
The Mars rover said “w00t”. Here’s the w00t-less press release and the associated images that show the ice sublimating from the surface over the last four days.
When two plastics (polymers TTF and TCNQ) are placed atop one another, a thin strip forms that conducts electricity “as well as a metal”.
The TTF-TCNQ interface conducts electricity much better than standard semiconductors. “The electron concentration there is an order of magnitude higher,” Mannhart says. “That has the power to create new effects, from magnetism to superconductivity.”
All blacks are not created equal…a team at Rensselaer and Rice University have created the world’s darkest material. Plain old black paint reflects between 5 and 10 percent of incident light; the new material reflects only 0.045%. (via animamundi)
The idea of evolution did not begin with Darwin…he just (just!) explained how it happened and backed it up with evidence.
“The only novelty in my work is the attempt to explain how species become modified,” Darwin later wrote. He did not mean to belittle his achievement. The how, backed up by an abundance of evidence, was crucial: nature throws up endless biological variations, and they either flourish or fade away in the face of disease, hunger, predation and other factors. Darwin’s term for it was “natural selection”; Wallace called it the “struggle for existence.” But we often act today as if Darwin invented the idea of evolution itself, including the theory that human beings developed from an ape ancestor. And Wallace we forget altogether.
In fact, scientists had been talking about our primate origins at least since 1699, after the London physician Edward Tyson dissected a chimpanzee and documented a disturbing likeness to human anatomy. And the idea of evolution had been around for generations.
Rampant speculation from Jonah Lehrer on why people care so much when they watch overpaid athletes play sports. It is, perhaps, all about mirror neurons:
“The main functional characteristic of mirror neurons is that they become active both when the monkey makes a particular action (for example, when grasping an object or holding it) and when it observes another individual making a similar action.” In other words, these peculiar cells mirror, on our inside, the outside world; they enable us to internalize the actions of another. They collapse the distinction between seeing and doing.
This suggests that when I watch Kobe glide to the basket for a dunk, a few deluded cells in my premotor cortex are convinced that I, myself, am touching the rim. And when he hits a three pointer, my mirror neurons light up as I’ve just made the crucial shot. They are what bind me to the game, breaking down that 4th wall separating fan from player. I’m not upset because my team lost: I’m upset because it literally feels like I lost, as if I had been on the court.
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