(Source: news.discovery.com)
20 Things You Didn’t Know About Fire
1 Fire is an event, not a thing. Heating wood or other fuel releases volatile vapors that can rapidly combust with oxygen in the air; the resulting incandescent bloom of gas further heats the fuel, releasing more vapors and perpetuating the cycle.
2 Most of the fuels we use derive their energy from trapped solar rays. In photosynthesis, sunlight and heat make chemical energy (in the form of wood or fossil fuel); fire uses chemical energy to produce light and heat.
3 So a bonfire is basically a tree running in reverse.
4 Assuming stable fuel, heat, and oxygen levels, a typical house fire will double in size every minute.
5 Earth is the only known planet where fire can burn. Everywhere else: Not enough oxygen.
6 Conversely, the more oxygen, the hotter the fire. Air is 21 percent oxygen; combine pure oxygen with acetylene, a chemical relative of methane, and you get an oxyacetylene welding torch that burns at over 5,500 degrees Fahrenheit—the hottest fire you are likely to encounter.
7 Oxygen supply influences the color of the flame. A low-oxygen fire contains lots of uncombusted fuel particles and will give off a yellow glow. A high-oxygen fire burns blue.
8 So candle flames are blue at the bottom because that’s where they take up fresh air, and yellow at the top because the rising fumes from below partly suffocate the upper part of the flame.
9 Fire makes water? It’s true. Place a cold spoon over a candle and you will observe the water vapor condense on the metal…
10 …because wax—like most organic materials, including wood and gasoline—contains hydrogen, which bonds with oxygen to make H2O when it burns. Water comes out your car’s tailpipe, too.
11 We’ve been at this a long time: Charred bones and wood ash indicate that early hominids were tending thefirst intentional fires more than 400,000 years ago.
12 Nature’s been at it awhile, too. A coal seam about 140 miles north of Sydney, Australia, has been burning by some estimates for 500,000 years.
13 The ancient Greeks started fire with concentrated sunlight. A parabolic mirror that focuses solar rays is still used to ignite the Olympic torch.
14 Every 52 years, when their calendar completed a cycle, the Aztecs would extinguish every flame in the empire. The high priest would start a new fire on the ripped-open chest of a sacrificial victim. Fires fed from this flame would be distributed throughout the land.
15 Good burn: The 1666 Great Fire of London destroyed 80 percent of the city but also ended an outbreak of bubonic plague that had killed more than 65,000 people the previous year. The fire fried the rats and fleas that carried Yersinia pestis, the plague-causing bacterium.
16 The Peshtigo Fire in Wisconsin was the second deadliest blaze in United States history, taking 1,200 lives—four times as many as the Great Chicago Fire. Both conflagrations broke out on the same day: October 8, 1871.
17 America’s deadliest fire took place April 27, 1865, aboard the steamship Sultana. Among other passengers were 1,500 recently released Union prisoners traveling home up the Mississippi when the boilers exploded. The ship was six times over capacity, which helps explain the death toll of 1,547.
18 The Black Dragon Fire of 1987, the largest wildfire in modern times, burned some 20 million acres across China and the Soviet Union, an area about the size of South Carolina.
19 Spontaneous combustion is real. Some fuel sources can generate their own heat—by rotting, for instance. Pistachios have so much natural oil and are so prone to heat-generating fat decomposition that the International Maritime Dangerous Goods Code regards them as dangerous.
20 Haystacks, compost heaps, and even piles of old newspapers and magazines can also burst into flame. A good reason to recycle DISCOVER when you are done.
20 Things You Didn’t Know About Time
1 “Time is an illusion. Lunchtime doubly so,” joked Douglas Adams in The Hitchhiker’s Guide to the Galaxy. Scientists aren’t laughing, though. Some speculative new physics theories suggest that time emerges from a more fundamental—and timeless—reality.
2 Try explaining that when you get to work late. The average U.S. city commuter loses 38 hours a year to traffic delays.
3 Wonder why you have to set your clock ahead in March? Daylight Saving Time began as a joke by Benjamin Franklin, who proposed waking people earlier on bright summer mornings so they might work more during the day and thus save candles. It was introduced in the U.K. in 1917 and then spread around the world.
4 Green days. The Department of Energy estimates that electricity demand drops by 0.5 percent during Daylight Saving Time, saving the equivalent of nearly 3 million barrels of oil.
5 By observing how quickly bank tellers made change, pedestrians walked, and postal clerks spoke, psychologists determined that the three fastest-paced U.S. cities are Boston, Buffalo, and New York.
6 The three slowest? Shreveport, Sacramento, and L.A.
7 One second used to be defined as 1/86,400 the length of a day. However, Earth’s rotation isn’t perfectly reliable. Tidal friction from the sun and moon slows our planet and increases the length of a day by 3 milliseconds per century.
8 This means that in the time of the dinosaurs, the day was just 23 hours long.
9 Weather also changes the day. During El Niño events, strong winds can slow Earth’s rotation by a fraction of a millisecond every 24 hours.
10 Modern technology can do better. In 1972 a network of atomic clocks in more than 50 countries was made the final authority on time, so accurate that it takes 31.7 million years to lose about one second.
11 To keep this time in sync with Earth’s slowing rotation, a “leap second” must be added every few years, most recently this past New Year’s Eve.
12 The world’s most accurate clock, at the National Institute of Standards and Technology in Colorado, measures vibrations of a single atom of mercury. In a billion years it will not lose one second.
13 Until the 1800s, every village lived in its own little time zone, with clocks synchronized to the local solar noon.
14 This caused havoc with the advent of trains and timetables. For a while watches were made that could tell both local time and “railway time.”
15 On November 18, 1883, American railway companies forced the national adoption of standardized time zones.
16 Thinking about how railway time required clocks in different places to be synchronized may have inspiredEinstein to develop his theory of relativity, which unifies space and time.
17 Einstein showed that gravity makes time run more slowly. Thus airplane passengers, flying where Earth’s pull is weaker, age a few extra nanoseconds each flight.
18 According to quantum theory, the shortest moment of time that can exist is known as Planck time, or 0.0000000000000000000000000000000000000000001 second.
19 Time has not been around forever. Most scientists believe it was created along with the rest of the universe in the Big Bang, 13.7 billion years ago.
20 There may be an end of time. Three Spanish scientists posit that the observed acceleration of the expanding cosmos is an illusion caused by the slowing of time. According to their math, time may eventually stop, at which point everything will come to a standstill.
20 Things You Didn’t Know About Water
1 Water is everywhere—there are 332,500,000 cubic miles of it on the earth’s surface. But less than 1 percent of it is fresh and accessible, even when you include bottled water.
2 And “fresh” can be a relative term. Before 2009, federal regulators did not require water bottlers to remove E. coli.
3 Actually, E. coli doesn’t sound so bad. In 1999 the Natural Resources Defense Council found that one brand of spring water came from a well in an industrial parking lot near a hazardous waste dump.
4 Cheers! The new Water Recovery System on the International Space Station recycles 93 percent of astronauts’ perspiration and urine, turning it back into drinking water.
5 Kurdish villages in northern Iraq are using a portable version of the NASA system to purify water from streams and rivers, courtesy of the relief group Concern for Kids.
6 Ice is a lattice of tetrahedrally bonded molecules that contain a lot of empty space. That’s why it floats.
7 Even after ice melts, some of those tetrahedrons almost always remain, like tiny ice cubes 100 molecules wide. So every glass of water, no matter what its temperature, comes on the rocks.
8 You can make your own water by mixing hydrogen and oxygen in a container and adding a spark. Unfortunately, that is the formula that helped destroy the Hindenburg.
9 Scientists have a less explosive recipe for extracting energy from hydrogen and oxygen. Strip away electrons from some hydrogen molecules, add oxygen molecules with too many electrons, and bingo! You get an electric current. That’s what happens in a fuel cell.
10 Good gardeners know not to water plants during the day. Droplets clinging to the leaves can act as little magnifying glasses, focusing sunlight and causing the plants to burn.
11 Hair on your skin can hold water droplets too. A hairy leg may get sunburned more quickly than a shaved one.
12 Vicious cycle: Water in the stratosphere contributes to the current warming of the earth’s atmosphere. That in turn may increase the severity of tropical cyclones, which throw more water into the stratosphere. That’s the theory, anyway.
13 The slower rate of warming in the past decade might be due to a 10 percent drop in stratospheric water. Cause: unknown.
14 Although many doctors tell patients to drink eight glasses of water a day, there is no scientific evidence to support this advice.
15 The misinformation might have come from a 1945 report recommending that Americans consume about “1 milliliter of water for each calorie of food,” which amounts to 8 or 10 cups a day. But the report added that much of that water comes from food—a nuance many people apparently missed.
16 Call waterholics anonymous: Drinking significantly more water than is needed can cause “water intoxication” and lead to fatal cerebral and pulmonary edema. Amateur marathon runners have died this way.
17 Scientists at Oregon State University have identified vast reservoirs of water beneath the ocean floor. In fact, there may be more water under the oceans than in them.
18 Without water, ocean crust would not sink back into the earth’s mantle. There would be no plate tectonics, and our planet would probably be a lot like Venus: hellish and inert.
19 At the other end of the wetness scale, planet GJ 1214b, which orbits a red dwarf star, may be almost entirely water.
20 Recent evidence suggests that when the solar system formed 4.5 billion years ago, comets had liquid cores. If so, life may have started in a comet.
14 Fun Facts About Jellyfish
1) A group of fish is called a school. A gathering of dolphins is a pod. Several otters makes up a romp. And an assemblage of jellies is a swarm or, better yet, a smack.
2) “Swarm” and “bloom” should not be used interchangeably when talking about jellies. A swarm refers to jellies that collect in one area as a result of strong winds or currents, whereas a bloom is a dense cloud of jellies caused by an actual spike in reproduction.
3) Jellies are 95 percent water.
4) Musician Frank Zappa is the namesake of one species of jelly,Phialella zappai. (For an explanation, see Smithsonianwriter Abigail Tucker’s story, “Extreme Jellyfish.”)
5) Though jellies are soft-bodied and lack a skeleton, making fossils rare, there is evidence that jellyfish predate dinosaurs by some 400 million years.
6) A historic moment for jellyfish came in May 1991, when 2,478 moon jelly polyps and babies were launched into space aboard the shuttle Columbia. Biologist Dorothy Spangenberg of the Eastern Virginia Medical School wanted to learn about how weightlessness affected the development of juvenile jellies. She monitored calcium loss in the jellies, which by extension could further scientists’ understanding of humans’ calcium loss in space.
7) Some jellyfish, such as blubber jellies, a delicacy in parts of Asia, are edible. A former colleaguewrote about her culinary adventure tasting jellyfish in Washington D.C.’s Chinatown.
8) Most jellyfish live anywhere from a few hours to a few months. But a species of jelly calledTurritopsis nutricula may be immortal. The jelly reportedly can play its lifecycle in reverse, transforming from an adult medusa back to an immature polyp.
9) Jellies have been known to eat other jellies.
10) The creatures lack not only bones, but heads, hearts and brains.
11) Researchers from the Monterey Bay Aquarium Research Institute surmise that cross jellies (Mitrocoma cellularia), common to Monterey Bay in the spring and summer, can “smell” prey through chemicals in the water.
12) A recent study found that four of the box jellyfish Tripedalia cystophora‘s 24 eyes always point up. The jellyfish looks through the water surface for tree branches. This way, it can swim towards mangrove swamps where it feeds.
13) GFP, a green fluorescent protein found in crystal jellies, has important medical applications. Mayo Clinic scientists recently inserted a version of GFP and a gene from a rhesus macaque known to block a virus that causes feline AIDS into a cat’s unfertilized eggs. When the kittens were born, they glowed green in ultraviolet light, indicating that the gene was successfully transferred. Biologist Osamu Shimomura won a Nobel Prize in Chemistry in 2008 for discovering GFP.
14) Jellyfish can sting even when they are dead. In 2010, about 150 swimmers at Wallis Sands State Park in New Hampshire were stung by the floating, 40-pound carcass of a lion’s mane jellyfish.
1. Petrichor: That clean, greenish smell of rain. (Actually, it’s the smell of rain on dry earth produced by the chemical compound geosmin.)
2. Zarf: A metal chalice used to keep the heat from your coffee from burning your fingers, which has morphed into the modern-day cardboard sleeve that comes wrapped around your hot coffee.
3. Chanking: Chewed-up food that’s been spit out.
4. Scroop: The rustling, swooshy sound ballgowns make. More specifically, it’s the sound produced by the movement of silk.
5. Armsayes: Armholes of a T-shirt.
6. Glabella: The space between the eyebrows.
7. Nef: An extravagant table-ornament in the shape of a ship.
8. Feat: Aside from being an act requiring great strength, it describes a dangling curl of hair.
9. Badinage: Playful, joking banter.
10. Roorback: A damaging lie made publicly known for political effect.
Bonus: Grawlix: Typographical symbols standing for profanities, which appear in dialogue balloons in the place of actual dialogue. (What the f@$&!) ;)
Anvil Cloud, Western Africa
Under specific conditions, the towering, fluffy white clouds known as cumulonimbus can become flattened into the shape of an anvil. The anvil in the image above was captured by astronauts aboard the International Space Station as it crossed over western Africa in February 2008.
Cumulonimbus clouds form when air warmed by sun-heated ground rises. If the warm air contains water vapor and it encounters cooler air, the moisture condenses into water droplets. The air continues to rise, expand and cool as atmospheric pressure and temperature decrease. At the same time, heat released from the phase transition between water vapor and liquid water warms the air. The cooler air wants to fall, while the warmed air wants to rise, which sets up convection cells that feed the tall cloud towers and often result in thunderstorms.
In the tropics, these towers can grow to be 12 miles tall. At this point, they hit the tropopause, which is the boundary between the troposphere and stratosphere layers of the atmosphere. Beyond the tropopause, air no longer cools as it rises, which stops the cloud top, which may then spread and flatten along the boundary.
(Source: Wired)
10 Science and Technology Breakthroughs That Caused Widespread Panic
New ideas can be scary — and that includes new scientific and technological discoveries. When inventors create a brand new device, the futureshock can drive people insane with fear. Over the years, people have been sure that everything from Halley’s Comet to cellphones would bring the world to an end.
Take a look at the top 10 scares that science has caused.
10. Cars and Trains
“Rail travel at high speed is not possible because passengers, unable to breathe, would die of asphyxia.” This is the kind of thing that doctors, like Dr Dionysys Larder at University College London, believed in the early 1800s. There were all kinds of objections to rail travel, including those of Martin Van Buren. He believed that ‘the Almighty certainly never intended that people should travel at such breakneck speed,’ referring to the current limit of fifteen miles per hour. As time went on, people continued to believe that travel at upwards of fifteen miles, thirty-five miles, and fifty miles would snatch the breath out of passenger’s lungs and peel off their faces.
9. Electricity
It’s alive! It’s alive! This wasn’t so much a big scare as a slow burn. As soon as it was shown that a little electricity could make a frog’s leg jump, people began talking about its miraculous re-animating properties, and that myth has never entirely gone away. We no longer think you can shock a corpse made of many component parts sewn together to life, but we still think, assisted ably by television, that a stopped heart can be shocked back to life with a defibrillator even though it won’t do one bit of good. Electricity’s capacity for dealing out death was also of concern to people. President Benjamin Harrison had staff members turn lights on and off, because he was frightened of doing it himself. And the general public resisted electric doorbells for years because of the same fears.
8. Clones
Oh, Dolly. What brief havok you unleashed. The cloned sheep was hailed as the beginning of a new era in the world, in a version of a person could live forever, cloned from its host. Armies of clones could be raised. People could clone themselves and then edit their genes, giving rise to armies of subservients and supermen. Except Dolly herself didn’t turn out as that great a sheep. Although she bred and gave birth to several lambs, she lived about half as long as other sheep, and had severe arthritis and lung infections. An extinct Ibex, brought back from a tissue sample as a clone, lived only seven minutes, and was also stricken with lung problems. The fact is, whatever scientists want, be it a human or a sheep, can be made most easily by getting two existing animals together. And the kinks in the cloning technique haven’t been worked out enough to warrant bringing back other animals.
7. Halley’s Comet
No, no one thought Halley’s Comet would actually hit the Earth and kill everyone. (Or actually, some people probably thought that, but that wasn’t the main story.) Instead of buying telescopes to observe the comet streak across the sky, in 1910, people bought gas masks. They were sure that the comet would start a chemical shift in the atmosphere and turn the whole atmosphere on Earth to nitrous oxide. Yes, laughing gas. They were sure that the entire world would die laughing. Other people just thought the ‘cometary gases’ would mix with the atmosphere and poison everyone. The fact that it had come around regularly didn’t stop them from talking, proving that at least some people will freak out over anything.
6. Radioactive Elements
Radioactivity caused both a panic and a gold rush. Scientists worried early on about radioactivity, and of course movies came out which indicated that the radioactivity would turn animals giant or tiny or super smart. During World War II, after bombing raids, scientists would discreetly go out and check for radioactive elements in the area, seeing if the other side was using ‘dirty bombs.’ Meanwhile, the public was fascinated with the strange ‘energy’ that came out of these exotic elements. Surely energy would be good for anyone, and so it was put in cocktails, toothpaste, face cream, bread, and anything else they could think of. Towards the end of World War II, as the Allies were rolling into Germany, they sent people out to ascertain the progress of the German nuclear program. They were alarmed when they learned that a German company had made moves to acquire large amounts of various radioactive materials … until they learned that the company was trying to build up a supply to sell as tonics after the war. Radioactivity was both a terror and a panacea.
5. The First Nuclear Bomb
This was a small scare, but an intense one, as it caused one Manhattan Project scientist, Arthur Compton, to write, “Better to accept the slavery of the Nazis than run a chance of drawing the final curtain on mankind!” What kicked it off? Another Manhattan scientist, Edward Teller did a quick calculation which indicated that nuclear fission, on the scale of a fission bomb, could ignite the hydrogen in Earth’s atmosphere and make the world into a fireball. This caused some concern, to the tune of every scientist available being pulled from their work and ordered to work out whether the bomb would work as predicted or whether the President would have just enough time to say ‘oops,’ as the advancing wall of flame hit Washington DC. Unanimously, the scientists came back with figures which indicated that the world was not going to end with one nuclear bomb. Which is, of course, why it was necessary to come up with enough nuclear bombs to cause the end of the world.
4. The Large Hadron Collider
This science scare proves that it’s not that we don’t learn, it’s just that sometimes we know it’s more fun to choose not to. People speculated about everything from the LHC creating a giant black hole that would suck everything around it in to a ‘runaway fusion reaction’ in nitrogen tanks that the LHC didn’t actually have. And it was fun. Some scares are like seasoning. They add some bite to science. Although the LHC did put up an entire page allaying public concern, but they didn’t really.
3. Cell Culture
The ability to keep cells alive in lab dishes was tirelessly sought after in the early part of the twentieth century, but when it looked like it was possible, many people were worried about the consequences. The whole scare started when a scientist (probably falsely) claimed that he was keeping chicken heart cells alive in a lab. People wrote stories about the cells staying alive and multiplying like the blob or cells infecting everyone and getting into everything. But when the fearmongers really started stretching their legs, things got impressive. Living cells could be made into anything, they said, spouting futures in which the world was full of two-headed toads (no sure why that’s threatening to anyone except the toads) or animals with human minds. One expert wrote a book about how cell cultures would cause the world to be populated with ‘giant negroes.’ I say if time travel is ever invented, we need to find that author, and a volunteer group of professional basketball players needs to go back in time and scare the hell out of him.
2. Extinction
This is a good one to fear, I think. And it was one that no one feared for centuries. Although many collectors unearthed strange, huge fossils from animals that weren’t seen in the area any more, it was assumed they were somewhere else. After all, the massive tusked animals whose skulls had been excavated all over the world had contemporaries in Africa and India. Whatever else was dug up out of the ground had to be lurking somewhere. Some thought that God would not let his creations go extinct. Others thought that animals didn’t die out, they simply changed. George Cuvier, a gifted paleontologist who his contemporaries said ‘could reconstruct a skeleton from a single bone,’ gathered evidence, both biological and geographic, that some species didn’t blend with others or shrink down or get bigger. They were killed. He proved, to almost anyone who would look, that extinction was real, and that it often had to do with massive geological or environmental events. He steered the scientific community towards both extinction and catastrophism, and so is partially responsible for every item on this list.
1. Writing
No less a source than Socrates was worried about this new-fangled thing called writing that he’d heard about. He warned people that, “create forgetfulness in the learners’ souls, because they will not use their memories.” It was isolating as well. More importantly, he worried about all those children learning to read whatever writing they got their hands on. If they did, they could independently read horrible, immoral, or overly-fanciful tales that would warp their minds. If this is sounding awfully familiar to you, it’s because it sounds familiar to everyone. The same was said about the printing press, the radio, the television, and the movies. Of course it’s also been said about the internet. A recent study that warned that the internet, easy access to all kinds of written material, will take out our memory. This historical scare can give consolation to both sides. Those who feel it’s overblown can point out that the more things change the more they stay the same. Those who want us to heed the warning can mention that they are on the side of Socrates.
Top Ten Myths About the Brain
When it comes to this complex, mysterious, fascinating organ, what do—and don’t—we know?
By Laura Helmuth
1. We use only 10 percent of our brains.
This one sounds so compelling—a precise number, repeated in pop culture for a century, implying that we have huge reserves of untapped mental powers. But the supposedly unused 90 percent of the brain is not some vestigial appendix. Brains are expensive—it takes a lot of energy to build brains during fetal and childhood development and maintain them in adults. Evolutionarily, it would make no sense to carry around surplus brain tissue. Experiments using PET or fMRI scans show that much of the brain is engaged even during simple tasks, and injury to even a small bit of brain can have profound consequences for language, sensory perception, movement or emotion.
2. “Flashbulb memories” are precise, detailed and persistent.
We all have memories that feel as vivid and accurate as a snapshot, usually of some shocking, dramatic event—the assassination of President Kennedy, the explosion of the space shuttle Challenger, the attacks of September 11, 2001. People remember exactly where they were, what they were doing, who they were with, what they saw or heard. But several clever experiments have tested people’s memory immediately after a tragedy and again several months or years later.
3. It’s all downhill after 40 (or 50 or 60 or 70).
It’s true, some cognitive skills do decline as you get older. Children are better at learning new languages than adults—and never play a game of concentration against a 10-year-old unless you’re prepared to be humiliated. Young adults are faster than older adults to judge whether two objects are the same or different; they can more easily memorize a list of random words, and they are faster to count backward by sevens.
But plenty of mental skills improve with age. Vocabulary, for instance—older people know more words and understand subtle linguistic distinctions. Given a biographical sketch of a stranger, they’re better judges of character. They score higher on tests of social wisdom, such as how to settle a conflict. And people get better and better over time at regulating their own emotions and finding meaning in their lives.
4. We have five senses.
Sure, sight, smell, hearing, taste and touch are the big ones. But we have many other ways of sensing the world and our place in it. Proprioception is a sense of how our bodies are positioned. Nociception is a sense of pain. We also have a sense of balance—the inner ear is to this sense as the eye is to vision—as well as a sense of body temperature, acceleration and the passage of time.
5. Brains are like computers.
We speak of the brain’s processing speed, its storage capacity, its parallel circuits, inputs and outputs. The metaphor fails at pretty much every level: the brain doesn’t have a set memory capacity that is waiting to be filled up; it doesn’t perform computations in the way a computer does; and even basic visual perception isn’t a passive receiving of inputs because we actively interpret, anticipate and pay attention to different elements of the visual world.
6. The brain is hard-wired.
This is one of the most enduring legacies of the old “brains are electrical circuits” metaphor.
But one of the biggest discoveries in neuroscience in the past few decades is that the brain is remarkably plastic. In blind people, parts of the brain that normally process sight are instead devoted to hearing. Someone practicing a new skill, like learning to play the violin, “rewires” parts of the brain that are responsible for fine motor control. People with brain injuries can recruit other parts of the brain to compensate for the lost tissue.
7. A conk on the head can cause amnesia.
Next to babies switched at birth, this is a favorite trope of soap operas: Someone is in a tragic accident and wakes up in the hospital unable to recognize loved ones or remember his or her own name or history. (The only cure for this form of amnesia, of course, is another conk on the head.)
8. We know what will make us happy.
In some cases we haven’t a clue. We routinely overestimate how happy something will make us, whether it’s a birthday, free pizza, a new car, a victory for our favorite sports team or political candidate, winning the lottery or raising children. Money does make people happier, but only to a point—poor people are less happy than the middle class, but the middle class are just as happy as the rich. We overestimate the pleasures of solitude and leisure and underestimate how much happiness we get from social relationships.
9. We see the world as it is.
We are not passive recipients of external information that enters our brain through our sensory organs. Instead, we actively search for patterns (like a Dalmatian dog that suddenly appears in a field of black and white dots), turn ambiguous scenes into ones that fit our expectations (it’s a vase; it’s a face) and completely miss details we aren’t expecting. In one famous psychology experiment, about half of all viewers told to count the number of times a group of people pass a basketball do not notice that a guy in a gorilla suit is hulking around among the ball-throwers.
10. Men are from Mars, women are from Venus.
Some of the sloppiest, shoddiest, most biased, least reproducible, worst designed and most overinterpreted research in the history of science purports to provide biological explanations for differences between men and women. Eminent neuroscientists once claimed that head size, spinal ganglia or brain stem structures were responsible for women’s inability to think creatively, vote logically or practice medicine. Today the theories are a bit more sophisticated: men supposedly have more specialized brain hemispheres, women more elaborate emotion circuits. Though there are some differences (minor and uncorrelated with any particular ability) between male and female brains, the main problem with looking for correlations with behavior is that sex differences in cognition are massively exaggerated.
20 Things You Didn’t Know About Eclipses
In the image: Totality during the 1999 solar eclipse. Solar prominences can be seen along the limb (in red) as well as extensive coronal filaments.
1 The longest total solar eclipse of the century occurred on July 22 over India, Nepal, Bhutan, and China. It peaked over the Pacific Ocean, but even there the darkness lasted a mere 6 minutes and 29 seconds.
2 Fast and furious: The moon’s shadow zooms across Earth’s surface at up to 5,000 miles per hour.
3 Canadian astronomer and renowned eclipse chaser J. W. Campbell traveled the world for 50 years trying to see 12 different eclipses. He ran into overcast skies every time.
4 Don’t repeat J. W.’s mistakes: Monsoon season throughout south Asia means that there is a good chance the eclipse this July will be clouded out too.
5 Just before full eclipse, dazzling “Baily’s beads” appear where sunlight shines through valleys on the moon. The last bead creates the impression of a diamond ring in the sky.
6 On eclipse-viewing expeditions, this phenomenon is frequently accompanied by a marriage proposal.
7 The beautiful symmetry of a total solar eclipse happens because—by pure chance—the sun is 400 times larger than the moon but is also 400 times farther from Earth, making the two bodies appear the exact same size in the sky.
8 In case you were thinking about relocating: Earth is the only place in the solar system where that happens.
9 Other planets get other kinds of fun, though. Jupiter can have a triple eclipse, in which three moons cast shadows on the planet simultaneously. The event is easily visible through a backyard telescope.
10 The Chinese word for solar eclipse is shih, meaning “to eat.” In ancient China people traditionally beat drums and banged on pots to scare off the “heavenly dog” believed to be devouring the sun.
11 Then again, China also produced the first known astronomical recordings of solar eclipses, inscribed in pieces of bone and shell called “oracle bones,” from around 1050 B.C. or earlier.
12 By comparing those ancient records with modern calculations of eclipse patterns, scientists have determined that the day is 0.047 second longer today than it was back then.
13 Tidal friction, which causes that lengthening of the day, is also making the moon drift away. In about 600 million years it will appear too small to cover the sun, and there will be no more total solar eclipses.
14 In any given location, a total solar eclipse happens just once every 360 years on average.
15 Luckiest place on Earth Carbondale, Illinois, will beat the odds: Folks there will see an eclipse on August 21, 2017, and again on April 8, 2024.
16 In contrast, everyone on the night side of the world can see a lunar eclipse, where the moon slips into Earth’s shadow.
17 During a total lunar eclipse, the moon takes on a deep reddish hue due to the sunlight filtering through our atmosphere—the cumulative glow of all the world’s sunsets.
18 While stranded in Jamaica, Christopher Columbus was famously saved by the lunar eclipse of February 29, 1504, which he had read about in his almanac. After a fracas with the locals, Columbus warned that the moon would disappear if they did not start supplying his men with food.
19 When the moon vanished, the locals promptly complied, and Columbus breathed a huge sigh of relief: His almanac was calibrated for Germany, and he was not sure that he had adjusted correctly for local time.
20 Who knows—it might be useful to you, too. The next lunar eclipse visible from the United States will take place on December 21, 2010.
20 Things You Didn’t Know About Sugar
We eat it, we love it, and it may have been a chemical precursor to life on Earth.
Magnification of grains of refined sucrose, the most common free sugar.
1 The average American eats 61 pounds of refined sugar each year, including 25 pounds of candy. Halloween accounts for at least two pounds of that.
2 Trick: Sugar may give you wrinkles via a process called glycation, in which excess blood sugar binds to collagen in the skin, making it less elastic.
3 Or treat: Cutting back on sugar may help your skin retain its flexibility. So actually, no treats.
4 People in India have been crystallizing cane sugar for at least 2,000 years. When Alexander the Great’s companions arrived there, they marveled at the production of honey without bees.
5 In 1747 German chemist Andreas Marggraf discovered that the sugar in a sugar beet is identical to that in sugarcane. In 1802 the first beet-sugar refinery began operations, bringing cheap sweets to northern climes.
6 More than half the 8.4 million metric tons of sugar produced annually in the United States comes from beets.
7 Can you imagine eating 16 sugar cubes at one sitting? You probably have. That’s a little less than what is contained in a 20-ounce bottle of cola.
8 Soft drinks with artificial sweeteners may actually help make you fat. In a Purdue University study, rats drinking liquids with artificial sweeteners consumed more calories overall than rats whose drinks were sweetened with sugar.
9 The artificial sweeteners saccharin and aspartame were found accidentally when lab workers doing research that had nothing to do with sweetening put a bit of the test compounds in their mouths and liked what they tasted.
10 What kind of researcher sticks an experiment in his mouth?
11 At least he had an excuse. The scientists who discovered sucralose (now sold as Splenda) were originally trying to create an insecticide. An assistant thought he had been instructed to “taste” a compound he’d only been asked to “test.”
12 A compound called lugduname is the sweetest compound known—more than 200,000 times as sweet as table sugar.
13 Sugars are molecules of carbon, hydrogen, and oxygen. The simplest include glucose, fructose, and galactose. Table sugar is crystallized sucrose, a fusion of one fructose and one glucose molecule.
14 Can’t escape them: Sugars are the building blocks of carbohydrates, the most abundant type of organic molecules in living things.
15 Glycolaldehyde, an eight-atom sugar, has even been found in an interstellar gas cloud near the center of the Milky Way.
16 Glycolaldehyde can react with a three-carbon sugar to form ribose, the basis for both RNA and DNA, so the glycolaldehyde found in deep space may be a chemical precursor to life on Earth.
17 That cloud also contains ethylene glycol, a sweet relative of glycolaldehyde and the main ingredient in antifreeze. Either complex sugars can be synthesized between the stars or there is a truck stop at the end of the universe.
18 Sugar can help get you there to find out. Burn sucrose with a dose of corn syrup and saltpeter and you get “sugar propellant,” a popular amateur rocket fuel.
19 How do you spell relief? “Obecalp,” a sugar pill manufactured to FDA standards, is marketed as a treatment for children’s mild complaints. (Try reading the name backward.)
20 It’s not all mind games. The sugar glucosamine works as an immunosuppressant in mice, and xylitol (a sugar alcohol) can prevent ear infections in kids. Sweet!
![20 Things You Didn’t Know About Magnetism
The mystery of how to describe it, the mystery of where spin comes from, and the mystery of whether lightning makes rocks magnetic.
by Rebecca Coffey; illustration by
Jonathon Rosen
1 Magnetism is familiar to every fifth grader, but describing it can confound even the most brilliant physicist.
2 Take the case of Richard Feynman. When asked to explain magnetism, he urged his BBC interviewer to take it on faith (video). After seven minutes of stonewalling, he finally said, “I really can’t do a good job, any job, of explaining magnetic force in terms of something else that you’re more familiar with because I don’t understand it in terms of anything else that you’re more familiar with.”
3 He did break down and try for a few seconds before abandoning the attempt. Those seconds were packed with oversimplifications: “All the electrons [in a magnet] are spinning in the same direction.”
4 But who better than Feynman would have known that not all electrons spin in the same direction?
5 And they don’t actually spin. “Spin” is just a physicist’s term for the little magnetic north and south poles baked into every electron. The orientation of those poles defines the direction of the electron’s (somewhat imaginary) rotation.
6 Why does every electron have those poles? As soon as someone finds out, we’ll get back to you.
7 Here is what we do know. Within an atom, each electron is usually paired with an opposite-
oriented electron so that their magnetic pulls cancel each other out.
8 But if some of the electrons are unpaired, they can be induced to move around so that their poles line up, creating a net magnetic field. The arrangement of the electrons in metals makes them particularly open to magnetic peer pressure.
9 DIY refrigerator magnet: Apply an external magnetic field to some hot metal. Cool it so the aligned electrons get frozen in place. Slap on your local plumber’s business card, and—voilà!
10 Yin Seeks Yang for Magnetic Relationship. All magnets have north and south poles, and opposite poles attract: North poles seek south poles seek north poles seek south poles seek . . .
11 You are standing on a magnet right now. The earth’s magnetic field is created by electric currents in an ocean of molten iron at its core. That’s why the north pole of a compass needle points . . . er . . . why north? Since north poles are attracted to south poles, the “north” arrow on your compass actually points toward the earth’s south magnetic pole, which is the one up north. Got it?
12 And the earth’s magnetic south (aka “north”) pole isn’t even precisely at the geographic north pole. Right now it is in the Arctic Ocean, near northern Canada.
13 Worse still, it is constantly drifting in response to currents in the earth’s core. It is moving toward Siberia at a rate of up to 35 miles per year, according to the U.S. Geological Survey. Hey, shift happens.
14 Ancient mariners navigated by lodestone, naturally occurring magnetic rocks.
15 Where lodestones come from is another mystery of magnetism. Some geologists think they are created when lighting strikes iron-rich rocks.
16 Microbes, birds, and some other animals have magnetic crystals inside their bodies that allow them to orient themselves.
17 That is probably why loggerhead turtles can migrate 8,000 miles in unfamiliar waters while humans can get lost looking for the restroom at Olive Garden.
18 Magnetic Resonance Imaging (MRI) machines generate a field 60,000 times as intense as the earth’s to vibrate the hydrogen atoms in your body; in response, the atoms emit radio waves that are analyzed to produce a map of your insides.
19 Using a sensor the size of a sugar cube, researchers from the National Institute of Standards and Technology can track the magnetic pattern of a human heart.
20 The signal is faint, but the good news is that science has proved attraction is quantifiable. Word up, Hallmark.](http://24.media.tumblr.com/tumblr_lzkchl2iTU1qbkzabo1_400.jpg)
20 Things You Didn’t Know About Magnetism
The mystery of how to describe it, the mystery of where spin comes from, and the mystery of whether lightning makes rocks magnetic.
1 Magnetism is familiar to every fifth grader, but describing it can confound even the most brilliant physicist.
2 Take the case of Richard Feynman. When asked to explain magnetism, he urged his BBC interviewer to take it on faith (video). After seven minutes of stonewalling, he finally said, “I really can’t do a good job, any job, of explaining magnetic force in terms of something else that you’re more familiar with because I don’t understand it in terms of anything else that you’re more familiar with.”
3 He did break down and try for a few seconds before abandoning the attempt. Those seconds were packed with oversimplifications: “All the electrons [in a magnet] are spinning in the same direction.”
4 But who better than Feynman would have known that not all electrons spin in the same direction?
5 And they don’t actually spin. “Spin” is just a physicist’s term for the little magnetic north and south poles baked into every electron. The orientation of those poles defines the direction of the electron’s (somewhat imaginary) rotation.
6 Why does every electron have those poles? As soon as someone finds out, we’ll get back to you.
7 Here is what we do know. Within an atom, each electron is usually paired with an opposite- oriented electron so that their magnetic pulls cancel each other out.
8 But if some of the electrons are unpaired, they can be induced to move around so that their poles line up, creating a net magnetic field. The arrangement of the electrons in metals makes them particularly open to magnetic peer pressure.
9 DIY refrigerator magnet: Apply an external magnetic field to some hot metal. Cool it so the aligned electrons get frozen in place. Slap on your local plumber’s business card, and—voilà!
10 Yin Seeks Yang for Magnetic Relationship. All magnets have north and south poles, and opposite poles attract: North poles seek south poles seek north poles seek south poles seek . . .
11 You are standing on a magnet right now. The earth’s magnetic field is created by electric currents in an ocean of molten iron at its core. That’s why the north pole of a compass needle points . . . er . . . why north? Since north poles are attracted to south poles, the “north” arrow on your compass actually points toward the earth’s south magnetic pole, which is the one up north. Got it?
12 And the earth’s magnetic south (aka “north”) pole isn’t even precisely at the geographic north pole. Right now it is in the Arctic Ocean, near northern Canada.
13 Worse still, it is constantly drifting in response to currents in the earth’s core. It is moving toward Siberia at a rate of up to 35 miles per year, according to the U.S. Geological Survey. Hey, shift happens.
14 Ancient mariners navigated by lodestone, naturally occurring magnetic rocks.
15 Where lodestones come from is another mystery of magnetism. Some geologists think they are created when lighting strikes iron-rich rocks.
16 Microbes, birds, and some other animals have magnetic crystals inside their bodies that allow them to orient themselves.
17 That is probably why loggerhead turtles can migrate 8,000 miles in unfamiliar waters while humans can get lost looking for the restroom at Olive Garden.
18 Magnetic Resonance Imaging (MRI) machines generate a field 60,000 times as intense as the earth’s to vibrate the hydrogen atoms in your body; in response, the atoms emit radio waves that are analyzed to produce a map of your insides.
19 Using a sensor the size of a sugar cube, researchers from the National Institute of Standards and Technology can track the magnetic pattern of a human heart.
20 The signal is faint, but the good news is that science has proved attraction is quantifiable. Word up, Hallmark.
20 Things You Didn’t Know About Clouds
In the image: A lenticular cloud over the Tararua Mountains in the North Island of New Zealand
Courtesy: NASA
1 When moist, warm air rises to a cooler elevation, water condenses onto microscopic “seeds” like dust, ash, or bacteria. Water + seeds + updraft = clouds.
2 If there’s more water vapor than places for it to condense, already-formed ice crystals can also serve as seeds. As the crystals take on moisture, they may become too heavy for updrafts to support. Time for the umbrella.
3 It makes sense, then, that adding seeds to thin clouds should make them rain out. Believing the theory, 37,000 Chinese peasants shot rockets filled with silver iodide (a widely used seeding agent) into clouds.
4 So much for People Power. After reviewing 40 years of cloud-seeding efforts in an area north of Israel, researchers at Tel Aviv University have concluded that seeding doesn’t actually produce additional precipitation (pdf).
5 Super-seeding: A team led by Stephen Salter of the University of Edinburgh has proposed using 1,500 oceangoing ships to spray saltwater into stratocumulus clouds in order to increase our planet’s cloud cover.
6 They want to accomplish goals set out in 1990 by John Latham of the National Center for Atmospheric Research. He suggested that saturating the air with salt crystal seeds would create a haze of water droplets so small that they would never rain out. The intended result: A permanent, low-hanging cloud cover that would deflect sunlight and, in theory, reverse global warming.
7 But excess cloud cover might actually warm the planet by trapping heat.
8 In fact, a 2009 Stanford University study claims that clouds created by aircraft emissions triggered an overall rise in surface temperatures of 0.03 to 0.06 degree Celsius worldwide. That would account for 4 to 8 percent of the warming that has occurred since record keeping began in 1850.
9 Nacreous clouds, or “mother of pearl” clouds, appear iridescent because of their ultrafine ice crystals, which form 10 to 15 miles up in the stratosphere.
10 Unfortunately, nacreous clouds also support chemical reactions that convert benign chlorine-containing molecules into a form that destroys Earth’s ozone layer.
11 Roll clouds form when updrafts and downdrafts churn clouds into a long, spinning cylinder. They look spectacular, but they often herald an approaching storm front.
12 Highest of them all: 50 miles up, noctilucent, or “night shining,” clouds glow an eerie bluish white. They are invisible by day, but after sunset they catch solar rays shining from far below the horizon.
13 Noctilucent clouds seemed to first appear after the 1883 eruption of Krakatoa and are now a common sight.
14 A June 2010 hailstorm in South Dakota dropped the largest hailstone in U.S. history. It was nearly as large as a soccer ball and weighed two pounds.
15 Bad weather likes workdays. An Israeli-American team correlated 15 years of pollution records with the National Weather Service Storm Prediction Center’s records on storms. They found that hailstorms over the eastern United States peak in the middle of the week, when summertime air pollution is at its worst.
16 Cumulonimbus clouds are the ones that make your flight late. Their winds are so intense and unpredictable that pilots never go through them.
17 Not “through” but sometimes over.
18 In 1959 Lt. Col. William Rankin was flying his F-8 fighter jet over a cumulonimbus when the engine failed. He parachuted out and spent the next 30 minutes bounced around inside the storm. Amazingly, he survived.
19 In 2007 German paragliding champion Ewa Wisnierska experienced “cloud suck.” While gliding under a cumulonimbus, she was pulled upward to 32,000 feet. She blacked out due to lack of oxygen but regained consciousness at roughly 23,000 feet.
20 Referring to the dark clouds on the horizon, Wisnierska said, “Usually there is no problem.”
Rebecca Coffey’s blog, The Excuses I’m Going With, is at rebeccacoffey.blogspot.com
Hurricanes
Engines of Destruction
Hurricanes are giant, spiraling tropical storms that can pack wind speeds of over 160 miles (257 kilometers) an hour and unleash more than 2.4 trillion gallons (9 trillion liters) of rain a day. These same tropical storms are known as cyclones in the northern Indian Ocean and Bay of Bengal, and as typhoons in the western Pacific Ocean.
The Atlantic Ocean’s hurricane season peaks from mid-August to late October and averages five to six hurricanes per year.
Hurricanes begin as tropical disturbances in warm ocean waters with surface temperatures of at least 80 degrees Fahrenheit (26.5 degrees Celsius). These low pressure systems are fed by energy from the warm seas. If a storm achieves wind speeds of 38 miles (61 kilometers) an hour, it becomes known as a tropical depression. A tropical depression becomes a tropical storm, and is given a name, when its sustained wind speeds top 39 miles (63 kilometers) an hour. When a storm’s sustained wind speeds reach 74 miles (119 kilometers) an hour it becomes a hurricane and earns a category rating of 1 to 5 on the Saffir-Simpson scale.
Hurricanes are enormous heat engines that generate energy on a staggering scale. They draw heat from warm, moist ocean air and release it through condensation of water vapor in thunderstorms.
Hurricanes spin around a low-pressure center known as the “eye.” Sinking air makes this 20- to 30-mile-wide (32- to 48-kilometer-wide) area notoriously calm. But the eye is surrounded by a circular “eye wall” that hosts the storm’s strongest winds and rain.
These storms bring destruction ashore in many different ways. When a hurricane makes landfall it often produces a devastating storm surge that can reach 20 feet (6 meters) high and extend nearly 100 miles (161 kilometers). Ninety percent of all hurricane deaths result from storm surges.
A hurricane’s high winds are also destructive and may spawn tornadoes. Torrential rains cause further damage by spawning floods and landslides, which may occur many miles inland.
The best defense against a hurricane is an accurate forecast that gives people time to get out of its way. The National Hurricane Center issues hurricane watches for storms that may endanger communities, and hurricane warnings for storms that will make landfall within 24 hours.
Why Do We Yawn? It May Keep Us From Getting Hot-Headed
Yawning may activate a sinus “pump” that ventilates our brains.
In the Image: Chinese paramilitary police officers in Beijing.
Yawning may help you keep a cool head—literally, a new study suggests. The findings might hold some hope for sufferers of insomnia, migraines, and even epilepsy.
Though scientists have put forth various theories for yawning—from fatigue to lack of oxygen—none have held up to scrutiny.
“We can put a man on the moon, but we do not understand what the function of yawning is,” said study co-author Gary Hack, of the University of Maryland School of Dentistry in Baltimore.
Now, Hack and co-author Andrew Gallup, of Princeton University, propose that yawning causes the walls of the maxillary sinus to expand and contract like a bellows, pumping air onto the brain, which lowers its temperature. Located in our cheekbones, the maxillary are the largest of four pairs of sinus cavities in the human head.
Sinus Solution?
In addition to potentially solving the mystery of yawning, the study may also reveal why we have sinuses, whose existence has also stumped scientists.
It’s a “unified theory tying yawning, sinus ventilation, and brain cooling into a neat little package,” Hack said.
Ryan Soose—an ear, nose, and throat doctor as well as director of the University of Pittsburgh Medical Center’s Division of Sleep Surgery—added, “The hypothesis that these two relatively unknown things may be directly related, to me, is very intriguing.”
Cadaverous Clues
In 2002 study co-author Hack and his team were dissecting a cadaver when they discovered that the back wall of the maxillary sinus was much thinner—and therefore more flexible—than described in many medical textbooks.
“I’d always kept that in the back of my mind, because yawning was an exaggerated jaw movement that would have an impact on this previously undescribed pump in humans,” Hack said.
Later, he came across the postdoctoral research of Princeton’s Gallup, who in 2007 had become the first to suggest the brain-cooling theory for yawning.
Yawning Theory May Influence Medicine
Overall, understanding yawning could be a useful tool for diagnosing certain medical conditions, such as epilepsy and migraines, which are both preceded by excessive yawning, the scientists say.
Credits:
Published November 15, 2011
