Fire Projects | Make a Glowing Flower
It's commonly believed that taurine is an amino acid. There are a few reasons for the misconception. The chemical name for taurine is 2-aminoethanesulfonic acid, so it has an amino group and is an acid. Taurine has the "-ine" ending that is common with other amino acids, plus it is a nutritional supplement. However, the molecule does not have the amino acid structure. Taurine has a sulfonic acid group rather than the carboxyl group found in amino acids. Taurine is an important molecule in people and animals. It accounts for about 0.1% of total human body weight. It is a major component of bile and is used to moderate calcium signaling, osmoregulation, and proper muscle function. Human can synthesize taurine from the amino acid cysteine. However, cats and other carnivores cannot, so they have to obtain it from their diet. Taurine is important for development of other animals, too. Some birds seek out taurine-rich spiders to feed to their young.
Image: Chemistry Cat, like all other felines, needs taurine in his diet. Insufficient taurine leads to blindness, loss of fur, tooth decay, and eventually death.
If you're like me, you're lucky to pay attention to a recipe enough to notice whether you're supposed to be using baking powder or baking soda. Both ingredients cause baked goods to rise, but they are not interchangeable. Also, there is more than one type of baking powder. You can find single-acting baking powder and double-acting baking powder. You may be wondering how they are different or whether you should use half as much double-acting baking powder as single-acting baking powder. You use the exactly same amount of double-acting baking powder as you would single-acting baking powder. The difference between the two types of powder is their chemical composition and whether they produce the carbon dioxide gas bubbles that make your baked goods rise when the ingredients are mixed or when the product is heated in the oven. Both types of baking powder produce the same amount of gas, so they are equally effective as leavening agents.
Single-acting baking powder reacts with a water-based ingredient to form bubbles as soon as the ingredients are mixed. If you wait too long to bake your food or mix it too long these bubbles will escape and your food will fall flat.
Double-acting baking powder produces some bubbles when the ingredients are mixed, but most of the rising occurs once heat is applied. This product is more reliable for home baking because it is harder to overbeat the ingredients and the recipe is less susceptible to fail if you forgot to preheat your oven. Because it is practically failsafe, this is the type of baking powder most often found in stores. You'll encounter single-acting baking powder in commercial applications, plus this is the type of powder you would make if you prepare baking powder yourself.
Baking Powder Versus Baking Soda | Ingredient Substitutions
For the past few weeks, I've burned every 'wish dandelion' or dandelion seed head that I could find in South Carolina, Texas, and Nebraska. I've burned dandelions from ditches, dandelions from fields, dandelions treated with chemicals, and dandelions spritzed with flame colorants. A couple of my results are shown above. While you can get a dandelion to burn in multiple colors, the colors seem restricted to shades of orange, yellow and red. My next test is to burn a whole bouquet of dandelions, just in case I haven't been using a large enough sample size.
Have you burned dandelions trying to get the color effect? Have you seen anything unusual?
You can make nitrous oxide or laughing gas quite easily in the lab or at home. However, there are reasons why you might want to forego the preparation unless you have chem lab experience. Nitrous oxide (N2O) is also known as laughing gas. It is a colorless sweet-smelling and sweet-tasting gas that is used in dentistry and surgery because inhaling the gas produces analgesic and anesthetic effects. The gas is also used to produce the engine output of automotive vehicles and as an oxidizer in rocketry. Nitrous oxide gets the name "laughing gas" because inhaling it produces euphoria. Joseph Priestley first synthesized nitrous oxide in 1772 by collecting the gas produced from sprinkling nitric acid over iron filings, however, nitrous oxide usually is produced using Humphry Davy's method of gently heating ammonium nitrate to decompose it into nitrous oxide and water vapor: NH4NO3 (s) ? 2 H2O (g) + N2O (g)
The key here is gently heating the ammonium nitrate to between 170°C and 240°C, because higher temperatures may cause the ammonium nitrate to detonate. People have been doing this without incident for over 150 years, so they key is to be careful. Next, the hot gases are cooled to condense the water. The best way to do this is using a pneumatic trough, which involves a tube leading from the ammonium nitrate container that bubbles the gases up through water into a collection jar. This removes the water from the reaction as well as smoke from impurities in the ammonium nitrate. The gas in the collection jar is your nitrous oxide or laughing gas, plus lesser amounts of other nitrogen oxides, including nitric oxide or nitrogen monoxide. Nitric oxide is oxidized to nitrous oxide upon exposure to oxygen, although acid and base treatments are used to remove impurities for commercial-scale production of nitrous oxide. 
More Details on Nitrous Oxide Preparation
When I was trying to get dandelions to burn in colors I tried soaking the seed heads in a borax solution to get them to burn green. I left the flowers in the borax longer than I should have and ended up crystallizing the dandelions. Although the effect did not work for colored fire, it formed a stunning crystal flower. The only problem with the dandelion was that the stem shriveled and could not support the weight of the fragile crystal flower. I think twisting a pipecleaner or wire around the stem would have solved this problem, but I didn't have the materials on hand so I simply tried the project with a stronger flower. The subject shown in this photo is a musk thistle. As with dandelions, I'm reasonably sure no one in Nebraska objects to preventing one from going to seed (hah). Although you could add food coloring to the solution to tint the flower, what is neat about this project is the crystals take the color from the flowers. Dandelion crystal flowers are pale yellow. The thistle is lilac with a yellow center. You can use any flower for this project... Learn to make one yourself
A density column is a container of liquids that stack on top of each other because they have different densities. The heaviest liquid sinks to the bottom of the glass, while the lightest liquid floats at the top. A simple example of a density column is a mixture of oil and water. However, you can make density columns with more than two layers, plus you can color them. This pretty rainbow density column only requires sugar, water and food coloring! Rainbow in a Glass Video Tutorial | Step-By-Step Written Instructions
Chemical Fire #1
potassium permanganate glycerin waterAdd a few drops of glycerin to a few crystals of potassium permanganate. Accelerate the reaction by adding a couple of drops of water.
Chemical Fire #2 acetone sulfuric acid potassium permanganate
Soak a tissue with acetone to make it more flammable. Draw sulfuric acid into a glass pipette. Dip the pipette into potassium permanganate so that the tip of the pipette is coated with a few crystals. Dispense the sulfuric acid onto the tissue. The potassium permangante and sulfuric acid mix to produce manganese heptoxide and fire.
Chemical Fire #3 sodium chlorate sugar sulfuric acid
Mix a small amount of sodium chlorate and sugar. Initiate the reaction by adding a few drops of sulfuric acid.
Chemical Fire #4
ammonium nitrate powder finely ground zinc powder hydrochloric acidMix together a small amount of ammonium nitrate and zinc powder. Initiate the reaction by adding a few drops of hydrochloric acid.
Chemical Fire Safety
If you are performing a demonstration of chemical fire using any of these reactions, use very small amounts of the chemicals listed for each project. Wear proper safety gear and work on a fire-safe surface.
Here's an easy chemistry project you can do in which you take a clear liquid and instantaneously solidify it into hot 'ice'. It isn't water ice, however. This is how you make crystals of sodium acetate, which is used in hand warmers and chemical heating pads and hot packs.
Hot Ice Materials
sodium acetate water saucepan glass or panMaking Your Own Sodium Acetate Monohydrate
If you don't have any sodium acetate monohydrate you can make your own. Add baking soda (sodium bicarbonate) to vinegar (weak acetic acid) until the mixture stops fizzing. This will give you an aqueous solution of sodium acetate. If you boil off the water, you'll be left with the sodium acetate. Expect to use a lot of baking soda and vinegar if you go this route.
Make the Hot Ice
What you are going to do is make a supersaturated sodium acetate solution. The solution will remain a supercooled liquid until a little solid sodium acetate is introduced. This will cause rapid crystallization that will resemble a block of ice, except it will be hot to the touch and not edible.
Dump some sodium acetate monohydrate into a saucepan. Add just enough water to dissolve the sodium acetate. Heat the solution to just below its boiling point. Stir in more sodium acetate. Keep stirring and adding sodium acetate until you start to see solid material accumulating at the bottom of the pan. Pour the hot solution into a glass or other container. Do not allow any of the undissolved solid to enter the container. Cool the solution in the refrigerator 30 minutes to an hour. Remove the solution from the refrigerator. As long as you didn't leave any solid sodium acetate in the solution, it should still be liquid. When you are ready to make 'ice' introduce a little of the solid sodium acetate. You could dip a toothpick or the edge of a spoon in sodium acetate powder. The crystallization will evolve heat (exothermic reaction), making the solid feel hot to the touch (~130° F).Hot Ice Trick
You don't have to solidify the sodium acetate in a dish. You can crystallize it as the solution is being poured to make fantastic shapes.
Glitter usually gets its sparkle from polymer coatings over plastic or even from metals! Yet, it's easy to make non-toxic glitter or even edible glitter. This is perfect for young investigators and also for adults who want safe sparkle... Try itif(zs>0){if(zSbL250)gEI("spacer").style.height=Math.floor(e[0].height/12)+17.5+'em';else{var zIClns=[];function walkup(e){if(e.className!='entry'){if(e.nodeName=='A'||e.style.styleFloat=='right'||e.style.cssFloat=='right'||e.align=='right'||e.align=='left'||e.className=='alignright'||e.className=='alignleft')zIClns.push(e);walkup(e.parentNode)}}walkup(e[0]);if(zIClns.length){node=zIClns[zIClns.length-1];var clone=node.cloneNode(true);node.parentNode.removeChild(node);getElementsByClassName("entry",gEI("articlebody"))[0].insertBefore(clone,gEI("spacer"))}}}};zSB(2);zSbL=0When I was trying to get dandelions to burn in colors I tried soaking the seed heads in a borax solution to get them to burn green. I left the flowers in the borax longer than I should have and ended up crystallizing the dandelions. Although the effect did not work for colored fire, it formed a stunning crystal flower. The only problem with the dandelion was that the stem shriveled and could not support the weight of the fragile crystal flower. I think twisting a pipecleaner or wire around the stem would have solved this problem, but I didn't have the materials on hand so I simply tried the project with a stronger flower. The subject shown in this photo is a musk thistle. As with dandelions, I'm reasonably sure no one in Nebraska objects to preventing one from going to seed (hah). Although you could add food coloring to the solution to tint the flower, what is neat about this project is the crystals take the color from the flowers. Dandelion crystal flowers are pale yellow. The thistle is lilac with a yellow center. You can use any flower for this project... Learn to make one yourself
This theory explained many unknown chemical phenomenon of the time and was quickly adopted by chemists. Today, we see flaws with the overall theory. Dalton had no idea of the existence of parts of atoms and the existence of isotopes. He also didn't know that atoms could be created or destroyed through nuclear processes. In spite of this, his basic theory lives on in modern chemistry.
Find out what else occurred on this day in science history.
Follow About.com Chemistry on Facebook or Twitter.
Masers operate using a different method now, but the principle is the same. They are used to amplify microwaves, radar, and even in radio astronomy to detect very weak signals over a great distance. Find out what else occurred on this day in science history.
Follow About.com Chemistry on Facebook or Twitter.
NASA launched their first satellite in January 1958. In the next twenty years, they put men in space, landed men on the Moon, sent robotic probes to other planets and out of our solar system, created networks of satellites, built the Skylab space station and created a fleet of reusable Space Shuttles.
Find out what else occurred on this day in science history.
Former President Bill Clinton hugs House Minority Leader Nancy Pelosi of California as another Democrat, Sen. Barbara Boxer of California, looks on at Wednesday's ceremony naming the Environmental Protection Agency headquarters for him.
Pablo Martinez Monsivais/APThe environment may not come to mind when most people think about former President Bill Clinton, but on Wednesday he defended his legacy as the Environmental Protection Agency's headquarters in Washington, D.C., was renamed in his honor.
At a ceremony in the EPA complex, Clinton mentioned reading an article that questioned whether his was the right name to put on the building.
"I think it more than sort of fits — not for me, but for what we did. For what our administration did," Clinton said in remarks greeted by applause from a small crowd that included senators, a congressman and former members of his administration.
EPA/YouTubeA short clip from the comments former President Bill Clinton made on Wednesday at the renaming of the Environmental Protection Agency's headquarters in his honor.
Clinton cited actions his administration took that protected wild lands, coral reefs and old growth trees. He stressed that his EPA put in place rules to clean up exhaust from factories and vehicles and set the first air quality standards for soot.
"When I left office, there were 43 million more Americans breathing air that met federal standards, which means less asthma among young people and fewer senior citizens dying because of air pollution," Clinton said.
The former president credited the environmentalists on his team, including his Interior Secretary Bruce Babbitt, his EPA chief Carol Browner and his vice president, Al Gore (who was not among those at Wednesday's ceremony).
Judith Layzer, associate professor of environmental policy at the Massachusetts Institute of Technology, says that unlike Gore, President Clinton wasn't an environmentalist. But she says he stood up for the EPA in 1994. Congressional Republicans, led by Newt Gingrich, wanted to eliminate regulations. Some wanted to do away with the agency.
"Instead of backing down — the way liberals often do and the way environmentalists sometimes do and the way Clinton sometimes did — he really reared up and said, you know, we are going to protect environmental laws we are not going to let Congress gut them," says Layzer.
But Clinton's record didn't please all those who consider themselves to be environmentalists. He supported trade deals, such as the North American Free Trade Agreement that were criticized for hurting the environment. Environmentalists feared factories would move to countries without pollution laws, and polluting industries would set up just across the border with Mexico.
And although Clinton signed the international climate change treaty called the Kyoto Protocol, he failed to send it to Congress to be ratified.
In his speech Wednesday, Clinton mentioned that the Senate had made its opposition to the treaty clear to him. "It is the only bill I ever lost in Congress before I sent it to them, and an astonishing example of bipartisan cooperation in the Senate, which voted against it 98 to nothing," Clinton said.
The building that's been renamed after President Clinton is one of a string of imposing structures with limestone facades near the National Mall. It sits next to the Ronald Reagan Building and International Trade Center.
Clinton accepted his new honor in an ornate hall — with elaborately carved wooden ceiling and walls and crystal chandelier.
The former president also looked ahead during his remarks, saying that as he travels the world as an elder statesman, it is clear to him that these days leaders no longer have the option of ignoring climate change if they want to build jobs and strong economies.
"That is what the whole 21st century world is going to be about," he said.
Professor Chris Lowry needed to collect information on stream levels in Western New York but didn't have enough funding for the traditional methods, so he turned to a more creative option: crowdsourcing. Guest host Linda Wertheimer speaks with him about his research and the future of crowdsourcing in scientific inquiries.
Copyright © 2013 NPR. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.LINDA WERTHEIMER, HOST:
Scientific research can be expensive but a lack of funds did not stop one scientist in Buffalo from moving forward with his project. State University of New York professor Chris Lawry came up with a creative and cheap way to get measurements on stream levels across the state by crowdsourcing his research.
Chris Lawry joins us from member station WBFO in Buffalo, New York. Professor Lawry, thank you very much for coming in.
CHRIS LAWRY: Oh, thanks for having me.
WERTHEIMER: Tell us what you did. I mean, as I understand it, you basically just stuck a big ruler in the streams whose flow you were trying to measure and attached a sign with a phone number and asked passersby to send you a text message and tell you what the water level looked like.
LAWRY: That's exactly what we did do, and we realized that text messaging was ubiquitous and so as a result we thought maybe we can engage citizens and see if they can start to help us make these measurements. And so we literally stuck a sign in the stream and that sign said please text us the water level and it was right on top of basically just a giant ruler.
WERTHEIMER: Ha. You know, I still, I haven't asked you yet what exactly it is that you are doing with this information. Why do you want it?
LAWRY: My specific research is looking at ground water and surface water interactions. I literally set up these gauges so that I could know what was going on in terms of streams so I could better understand what's going on in the subsurface.
WERTHEIMER: If you're having passersby do your research, what do your colleagues think about that? I mean, do they think that that might just be a tiny bit too random?
LAWRY: You know, I think the jury's kind of out. What we've been able to show is we've been able to show that these data that come in are actually very accurate. It's just a matter of kind of convincing people that this is a new way of doing things. This is leveraging a new technology.
WERTHEIMER: Well, what about if you got some person coming by who was hostile to the idea or thought it would be a great idea laugh to send you some completely bogus results?
LAWRY: So that is possible, right? But because you're crowdsourcing, what we're doing is we're getting multiple measurements, so you may see that the water level is 3.5 feet and then it might go to 6.5 feet and then back to 3.5 feet. That 6.5 feet is an outlier and we can easily identify that and say you know what? That was a bad measurement. And I don't think that people are being hostile. I think people are inherently good, right? I think it's more of people with fat thumbs texting, right?
(LAUGHTER)
WERTHEIMER: I hope you're right.
LAWRY: I mean, I have fat thumbs. Like, I have a hard time texting. I'm not - I didn't grow up texting.
WERTHEIMER: Do you think you've actually saved money by doing it this way?
LAWRY: Oh, yeah. We saved a ton of money doing it this way, and it's also engaging people that aren't engaged in hydrologic sciences. This is a really cool, not only scientific endeavor, but it's also a really cool engagement endeavor.
WERTHEIMER: Professor Chris Lawry joined us from member station WBFO in Buffalo, New York. Thank you very much for being with us.
LAWRY: Thanks for having me.
WERTHEIMER: This is NPR News.
(SOUNDBITE OF MUSIC)
Copyright © 2013 NPR. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to NPR. This transcript is provided for personal, noncommercial use only, pursuant to our Terms of Use. Any other use requires NPR's prior permission. Visit our permissions page for further information.NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.Two recent eruptions on the sun sent solar tsunamis sweeping across its surface. Physicist David Long reported on the tsunamis in the journal Solar Physics, and he says the waves allowed him to calculate the magnetic field of a "quiet" area on the solar surface, which is 10 times weaker than a fridge magnet.
Copyright © 2013 NPR. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.IRA FLATOW, HOST:
Welcome back. I'm Ira Flatow. Look at the temperature map of the United States right now and the whole country is red. It's so hot that my E-ZPass fell of my windshield. It just melted right off there. But that's another story because there's weather in space also and my next guest says we might be able to fine tune our space weather forecasts by tracking an unusual phenomena - solar tsunamis.
That's right. Tsunamis not just here on Earth but on the sun. And it can ripple through the plasma of the sun at around a million miles per hour. And they're set off by enormous eruptions on the sun's surface. David Long is a solar physicist at the Mullard Space Science Laboratory, University College of London in Surrey in the U.K. He joins us by phone. Welcome to SCIENCE FRIDAY.
DAVID LONG: Hi. How are you? Thank you for having me.
FLATOW: You're welcome. What is a tsunami on the sun like?
LONG: Well, so what happens is you get these huge solar eruptions occurring in active regions. And sometimes we see these great waves of plasma, these bright fronts, moving away from the source of the eruption across the sun at really incredible speeds. So you said at a million miles an hour. And we see these as these are these solar tsunamis.
And what's really interesting to us is that how these tsunamis propagate across the sun can tell us an awful lot about the sun, about the sun's atmosphere, about the magnetic fields in the sun's atmosphere, how dense and magnetic the sun's atmosphere is.
FLATOW: Mm-hmm. How - you know, we talk about tsunamis here on Earth. How tall can a tsunami wave be on the sun?
LONG: Well, so the tsunamis that we're looking at are generally about 90 million meters above the photosphere, which is the visible surface of the sun. So they're quite high up in our terms but on the sun they're actually quite low down. This is the low atmosphere that we're talking about here.
FLATOW: Ninety million meters.
LONG: Yes.
FLATOW: You're not surfing that wave.
LONG: No.
(LAUGHTER)
FLATOW: And so what can you learn about the weather, the space weather? You were saying that you can learn things about the sun from it. What can you learn?
LONG: Well, so when we see these tsunamis, it generally means that there's - a blob of plasma has been fired out into space. And these blobs of plasma we call coronal mass ejections, or CMEs. Now, generally if we see one of these tsunamis it means that the blob of plasma is coming at the telescope. Which means that it's very difficult to measure how fast it's going, which is quite important when we want to predict when it might arrive at Earth, for example.
FLATOW: Right.
LONG: So we're hoping that by studying these tsunamis we might learn a little bit more about these CMEs. We might be able to work out how fast they are moving out into space.
FLATOW: Mm-hmm. Is this - are these recent discoveries, these tsunamis?
LONG: Well, actually, they were first observed in 1997 using a spacecraft called Soho. Now, the problem with Soho was that the cadence of the instruments - so it took one picture every 20 minutes, which means that it was quite difficult to see these tsunamis and we were quite lucky to see them in the first place. More recently we have an instrument, a spacecraft, called the Solar Dynamics Observatory, or SDO. And this was launched by NASA.
It takes an image every 12 seconds. So that really allows us to see these tsunamis. So we're starting to see them more and more, but that's probably a result of the fact that we have better instruments now. We have better telescopes for observing these phenomena.
FLATOW: Mm-hmm. So it might help you be able to predict a solar storm heading toward the planet, our planet.
LONG: Yes. Yes. That's the idea.
FLATOW: Yeah. And do you need any more special instruments for this? Or what you got, it's pretty good?
LONG: Well...
FLATOW: I should never ask that of a scientist.
(LAUGHTER)
LONG: So the instrument, the SDO spacecraft is really good. And it allows us to see the whole sun in one go. What was really unique about this work was we had a spectroscope. So we had an instrument called the Extreme Ultraviolet Imaging Spectrometer on a Japanese spacecraft called Hinode.
And this allowed us to measure the density of the sun's atmosphere. Now, the ice uses a very thin slit to measure density, which means that you have to be in the right place at the right time, and in this case we were. So we were able to get density measurements of the atmosphere. And then as the tsunami passed across the slate, we were able to use the measurements of how fast it was going and the density measurements to then estimate the magnetic field strength...
FLATOW: Right.
LONG: ...in the sun's atmosphere.
FLATOW: And so it's the magnetic field that's important here too.
LONG: Yes. So it's really difficult to measure the magnetic field...
FLATOW: Yeah.
LONG: ...in the sun's atmosphere. It's quite easy to do in active regions where this magnetic field is very concentrated. It's very strong and it's quite easy - it's relatively easy to measure there. What we were looking at was the quiet sun where everything is quite small. There's a lot of things going on but it's all very small scale and it's very difficult to see. And the magnetic field is very, very small.
FLATOW: Yeah. Yeah.
LONG: So it's very difficult to measure.
FLATOW: Well, before you go I have one question I have to ask because we've heard about this. That we're not seeing as much solar activity as we would expect about this time. What's going on there?
LONG: Well, so the sun has an 11 year cycle of activity. It's come out of a very long minimum and it's approaching or has reached maximum, which is quite small at the moment. And, I mean, that's really interesting. We are trying to understand why that is, why is this maximum so small. And why was the last minimum so long? And that's really a field of active research at the moment.
FLATOW: All right. We'll see what happens, if you can figure that out. Thank you. Thank you for taking time to be with us today.
LONG: No problem. Any time.
FLATOW: David Long, solar physicist at the Mullard Space Science Laboratory. That's at the University College London in Surrey, U.K.
Copyright © 2013 NPR. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to NPR. This transcript is provided for personal, noncommercial use only, pursuant to our Terms of Use. Any other use requires NPR's prior permission. Visit our permissions page for further information.NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.
This composite panorama image shows a proposed controlled-burn site in the Centennial Valley of southwestern Montana.
John W. Poole/NPRWildfires were once essential to the American West. Prairies and forests burned regularly, and those fires not only determined the mix of flora and fauna that made up the ecosystem, but they regenerated the land.
When people replaced wilderness with homes and ranches, they aggressively eliminated fire. But now, scientists are trying to bring fire back to the wilderness, to recreate what nature once did on its own.
One place they're doing this is Centennial Valley, in southwestern Montana.
Rimmed by snow-capped mountains, Centennial Valley is about as wild as it gets in the lower 48. In part, that's because the U.S. Fish and Wildlife Service, and now The Nature Conservancy, own big patches of it and keep it wild. But what's been missing there is fire.
Astronaut Luca Parmitano's helmet malfunctioned during Tuesday's space walk outside the International Space Station. Water built up inside, causing the excursion to be abandoned. Audie Cornish talks with NPR's Geoff Brumfiel about what happened yesterday, how serious it was, and what NASA believes could be the cause of the leak.
Copyright © 2013 NPR. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.AUDIE CORNISH, HOST:
We want to warn claustrophobics about our next story and alert aspiring screenwriters because in space, no one expects to drown. Yesterday, more than 200 miles above earth at the International Space Station, Luca Parmitano was about 90 minutes into a spacewalk when he noticed that his head was wet and getting wetter. Water then got into the Italian astronaut's eyes.
His spacewalking buddy, Chris Cassidy, took a quick look and saw nearly a pint of water floating around in Parmitano's helmet. The pair returned to the space station and removed his helmet as quickly as possible. Parmitano is fine. Joining me now is NPR's Geoff Brumfiel. He's been following the story. And Geoff, to start, what is NASA saying happened here, about the possible cause of this water leak?
GEOFF BRUMFIEL, BYLINE: Well, not very much. They had a press conference yesterday and talked about possible sources, but believe it or not, there are actually multiple sources of water in a space suit, so they're not sure where it came from.
CORNISH: I don't understand this. Why would there be water in a space suit in the first place?
BRUMFIEL: Well, the first reason is for the astronauts themselves. Spacewalking is kind of hard work. You're out there for several hours. You're doing physical labor, so they actually have drink bags inside the suits. The other reason is that even though you might think space is really cold, and it is, there's a need to regulate the temperature because you basically have no way to radiate your heat so they actually have these built in radiators that circulate water through the suit that help keep the astronauts cool.
CORNISH: So we're joking around here, but how serious was this yesterday for Parmitano?
BRUMFIEL: It was pretty serious. You know, they stayed calm, as everyone at NASA always does, but they did get him into the airlock quickly. Not as quickly as they would have done in a full-blown emergency, but they got the helmet off right away. They got the gloves off and they had to get him clear. I mean, the problem here is that water in space does not behave like water on earth.
Surface tension causes it to sort of glom together like mercury does, you know. Little beads of mercury will tend to clump up. And so what potentially could have happened is he would have this big floating blob of water in his helmet that he couldn't clear away 'cause it's in his helmet and he could've inhaled it. He could've choked or drowned. So it was potentially, actually, a pretty dangerous situation.
CORNISH: So what happens now? Will Parmitano get a chance to get out of there, to at least get a different suit?
BRUMFIEL: Well, the situation at the moment is that they have to figure out where this water actually came from. The leading candidate at the press conference yesterday was the cooling system, but they really don't know. And they also don't know whether it was an isolated incident or whether it's a problem with all of the space suits.
So in order to get the astronauts back out there, they're going to have to troubleshoot this and they spent all day doing that, the astronauts and mission control. They do have a backup space suit, so if it turns out to be a problem with this one spacesuit, they will probably go back out there at some stage.
And Parmitano's up there till November, so he may have a shot at it.
CORNISH: That's NPR's Geoff Brumfiel. Geoff, thank you so much.
BRUMFIEL: Thank you.
Copyright © 2013 NPR. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to NPR. This transcript is provided for personal, noncommercial use only, pursuant to our Terms of Use. Any other use requires NPR's prior permission. Visit our permissions page for further information.NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio. This composite panorama image shows a proposed controlled-burn site in the Centennial Valley of southwestern Montana.
John W. Poole/NPRWildfires were once essential to the American West. Prairies and forests burned regularly, and those fires not only determined the mix of flora and fauna that made up the ecosystem, but they regenerated the land.
When people replaced wilderness with homes and ranches, they aggressively eliminated fire. But now, scientists are trying to bring fire back to the wilderness, to recreate what nature once did on its own.
One place they're doing this is Centennial Valley, in southwestern Montana.
Rimmed by snow-capped mountains, Centennial Valley is about as wild as it gets in the lower 48. In part, that's because the U.S. Fish and Wildlife Service, and now The Nature Conservancy, own big patches of it and keep it wild. But what's been missing there is fire.
Fish oil may have some benefit for the heart. But a study in the Journal of the National Cancer Institute links higher blood levels of the omega-3 fatty acids in fish oil to a higher risk of prostate cancer. Study author Alan Kristal says the potential mechanism is unclear, but he warns that supplements can sometimes increase the risk of the very diseases they're meant to prevent.
Copyright © 2013 NPR. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.IRA FLATOW, HOST:
Welcome back. I'm Ira Flatow and our next story is destined to confuse you. It's one of those stories about nutrition, an update where new research seems to contradict old ideas, so let me just get right into it. We've all heard a lot of good news about fish oil and Omega-3 fatty acids.
(SOUNDBITE OF NEWSCASTS)
UNIDENTIFIED WOMAN #1: Omega-3 fatty acids may help reduce the risk of breast cancer.
UNIDENTIFIED WOMAN #2: The fish oil you need is Omega-3 fatty acids.
UNIDENTIFIED MAN #1: Omega-3 is protective in heart...
UNIDENTIFIED MAN #2: Fish oil may even slow the aging process...
UNIDENTIFIED WOMAN #3: It also helps people with diabetes, asthma, rheumatoid arthritis, osteoporosis, post-partum depression, and cancer.
FLATOW: And the list goes on. But last year a major study in the Journal of the American Medical Association said, hey, you know what? Omega-3 supplements don't really protect you against death from heart disease. And now a new study by my next guest adds to the bad news. It says men who had a higher level of Omega-3 fatty acids in their blood also had a higher risk of prostate cancer.
No cause and effect here, just a correlation. But it does make you wonder whether all these supplements and vitamins we take might be doing more harm than good. Alan Kristal is the author of the study in the journal of the National Cancer Institute. He's associate head of the cancer prevention program at the Fred Hutchinson Cancer Research Center in Seattle, professor of epidemiology at the University of Washington.
Welcome to the program, Dr. Kristal.
DOCTOR ALAN KRISTAL: Thanks very much.
FLATOW: Tell us exactly what you found.
KRISTAL: So the - this is based on a study of 35,000 men where we did a randomized trial looking at whether selenium or Vitamin E supplements would prevent prostate cancer. And one thing we did was we measured the levels of Omega-3 fatty acids in the blood of men as they entered the study and looked at how that related to prostate cancer risk.
And we found that high levels increased the risk of high-grade prostate cancer, which is the serious disease that actually kills you by over 70 percent. And it increased your risk of low-grade cancer by about 40 percent. And I should just add that we published a similar finding from a different study two years ago and we didn't really believe it, but we thought it was important to get it into the literature.
And now that we replicate it, it has some more immediacy. We begin to believe the association is true.
FLATOW: Does it matter where the Omega-3s come from, whether it's a supplement or, you know, you're just having some salmon?
KRISTAL: Yeah, I wish I could answer that very clearly, but I can say that most of the men in our study were not taking dietary supplements of Omega-3 fatty acids, so the high levels were coming from food.
FLATOW: Are you then recommending people don't eat fish, salmon and things like that?
KRISTAL: You know, that's the most complicated question you could ask me and I'd say this: Although the data on dietary supplements really doesn't support the use of Omega-3 fatty acids for anything and I want to emphasize that. There's no good data.
FLATOW: For anything? I just went through this long list, a little clip there, of everything that it was supposedly good for.
KRISTAL: It's, oh yes, things people want to believe about nutrition versus what scientists can tell you we know. It's an interesting list. But the point would be that there probably are benefits to fish consumption. The evidence points to Omega-3 fatty acids consumed as part of foods and that would be as part of fish reducing the risk of cardiovascular disease.
But it definitely shows, I think, that taking supplements has no impact. So there are some benefits, obviously, to eating salmon and other fatty fishes and, you know, it's a balance. There's a benefit for cardiovascular disease and I think there's clearly an increased risk for prostate cancer and, as I often say, none of us get out of this alive, so it's a balance.
FLATOW: Yeah. You know, first we hear it was Vitamin E was good; then it wasn't good. And then we hear Vitamin D - are we going to hear that something about Vitamin D now also?
KRISTAL: I'm pretty sure you will. I mean, if I look back on my career, which I've been doing this work for about 25 years now, we naively thought a long time ago that high doses of micronutrients would reduce risk of cardiovascular disease or various cancers. And as we test them rigorously, what we find it has no impact at all. Or worse we find that it increases the risk of the diseases we're very trying to prevent.
And it also increases the risk of other diseases we never thought it would affect.
FLATOW: Well, then how did we get the idea in the first place that these things were helpful?
KRISTAL: You know, that's a long story, but part of it has to do with the way we do nutrition research and the difficulty in measuring what people eat. So there are certain types of study designs that have inherent balances and the way that we measure food consumption when we have very large studies is actually very poor.
And so as we - so one thing we've done is we've moved to using biomarkers of dietary intake, so we can - I don't have to ask people how much Omega-3 fatty acids they eat; I can measure it in their bloods. And as you start doing the designs more rigorously, as you start measuring food intake more carefully, then, you know, you start narrowing down on the truth.
FLATOW: Yeah. So you've ruled out that it could be contaminants in some of the supplements?
KRISTAL: No, we can't rule out contaminants, and to be honest with you, we can't rule out the problem that plagues all this sort of research and that's that there may be something that characterizes men who eat fish that also increases their risk of prostate cancer and the association that we see isn't true, it isn't causal.
But on the other side, if you look at the number of studies, and there have been quite a few that have looked at Omega-3 fatty acids and prostate cancers, they all point to an increased risk except for one. So these have been done all over the world, these have been various kinds, different kinds of people, different sources of Omega-3 fatty acids, and they all point in the same direction.
FLATOW: To me what is most fearful about your results is that it increased the risk of the worst kind of cancer, that very fast-moving cancer.
KRISTAL: It does, but you have to remember that it's actually a rare disease. High-grade prostate cancer is very rarely diagnosed. It's no more than 18 percent or so of all prostate cancers detected.
FLATOW: But even then, the other prostate cancer, that's still up 40 percent.
KRISTAL: Right. You know, definitely a cause for concern and...
FLATOW: You must be getting pushback, a lot of pushback.
KRISTAL: Goodness yes. I have received the most vituperous(ph) email I've ever received in my career on this one. You know, people like to believe that the supplements they take improve their health and they're barraged by advertisements on this. And it's all, frankly, it's just not true.
FLATOW: But you're going up against people who will say there's all this other research that X, Y, Z contradicts what you're saying. Yeah?
KRISTAL: Not really. Not really. Now, what people say and the quality of the research it's based on is something that really requires a lot of critical scrutiny. There's a lot published on nutrition and disease and a lot of it, frankly, is not high quality work.
FLATOW: Is there any kind of supplement that you've looked at that you would suggest people take?
KRISTAL: Well, you know, you can look at, for example, folate supplementation of women of childbearing age. That has had a profound impact on neural tube defects, so that's really a success story that's translated into fortification of the food supply. I honestly can't say any condition where I think taking supplements really makes any sense.
FLATOW: But you're even saying here that it's not just the supplements. It could just be eating fish that are high in Omega-3s.
KRISTAL: Right. So in this case, yes. So here we have the issues that - I'll explain it this way. So we know Omega-3 fatty acids have a long range of biological effects. Some of them we understand quite well. And the issues is some of these effects would prevent some diseases while at the same time increasing the risk of other diseases.
You know, overall there's a balance and I will say that there's a very large trial ongoing right now looking at Vitamin D supplements and Omega-3 fatty acid supplements, both on men and women. I don't expect it to publish for another five years at least, but that's a trial that will really be informative on, you know, the balance.
It will increase the risk of some things, increase some risk of the others, and the question is what's the overall impact on quality of life and survival.
FLATOW: Do you have any preliminary results from that study?
KRISTAL: Oh no, it's not my study and...
FLATOW: So how does it affect you personally? Do you now, when you sit down in a restaurant, say oh I'm not ordering this salmon?
KRISTAL: Well, you know, the strangest thing in the world is that the day this came out I went downstairs to my cafeteria at work and I had a piece of salmon, so I really believe in the balance issue. To me, if you had one or two servings of salmon or a similar kind of oily fish a week, that's fine. It's when you get to higher levels that the possibility of a risk really exists.
FLATOW: Because people are taking those fish oil tablets every single day, multiple times a day, sometimes.
KRISTAL: Multiple times a day, right. You know, just the best advice I can ever give people is just to stop taking supplements. The evidence that they're beneficial for anything is so slim and the more quality research we do, these randomized trials, we find it increases the risk of really serious kind of diseases.
FLATOW: Is there money to do randomized trials that we need to do, because supplements, they're not, you know, they're not Viagra.
KRISTAL: That's right. So that's a big policy question and I'll just say that there was a lot more money to do these trials ten years ago. The effect of the decreased federal funding for scientific research has been profound over the last couple of years and the possibility of getting a large clinical trial done to test - to examine either nutrition or test dietary supplements just doesn't exist.
They're very expensive to do. they're hundreds of millions of dollars to do and there's no excitement to do them.
FLATOW: Thanks for being the barer of good news today, Alan.
KRISTAL: My pleasure. Thank you very much.
FLATOW: You're welcome. Alan Kristal, associate head of the Cancer Prevention Program at the Fred Hutchinson Cancer Research Centre in Seattle. Also professor of epidemiology at the University of Washington talking about stuff that was published in a very tough journal, The Journal of the National Cancer Institute. They don't put stuff in there that they don't believe in, so if he's put it in there and they've accepted it, it's a very, very good study.
Thank you, Alan, for taking time to be with us today.
KRISTAL: My pleasure.
FLATOW: We're going to take a break and next up, get out your drills and saws. You might want to swing by your Radio Shack, your Home Depot, your Lowes, whatever, because it's time for our summer do-it-yourself segment. We've got projects you can so out by the pool. How about a beverage barn? Yeah, how about a water bottle rocket launcher? How about a cooler that you can turn into a heater?
All kinds of projects we've got for you. Stay with us, we'll be right back after that.
(SOUNDBITE OF MUSIC)
FLATOW: I'm Ira Flatow. This is SCIENCE FRIDAY from NPR.
(SOUNDBITE OF MUSIC)
Copyright © 2013 NPR. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to NPR. This transcript is provided for personal, noncommercial use only, pursuant to our Terms of Use. Any other use requires NPR's prior permission. Visit our permissions page for further information.NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.I've got a friend, Destin, who has a YouTube channel called Smarter Every Day, where he pokes around with his camera to get extremely intimate looks at small miracles in nature. In this one, about the secret life of baby butterflies, he learns that when it comes time for the caterpillar to turn itself into a butterfly, it doesn't spin a lot of silk and build itself a shelter (a pupa). I thought that what caterpillars do. But no ... take a look at what actually happens.
There's another mystery here that Destin has yet to ponder. (But he says he will. He's working on it for later this year.) We've read, and reported on this blog that when it's time for caterpillars to transform themselves, once they are safe inside the pupa, they melt. That's what some experts say: they dissolve into a cytoplasmic goo, and cells they used as wormy little babies break down, and inside the pupa, the caterpillar becomes a soup. Then, somehow, that ooze gets rebuilt into a very differently shaped, flying, gorgeously colored adult. Most babies, like ducks, ants, people, birds, keep their form and just grow. Not moths and butterflies. They do a total makeover. How does that work? What is directing the resurrection? I don't know what kind of camera Destin will need to peek into the innards of a tiny, hard insect hideaway, but knowing Destin, he'll figure out something.
For bakers, turning a donut into a donut hole is simple. For a mathematician, it's impossible.
Copyright © 2013 NPR. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.ROBERT SIEGEL, HOST:
From NPR News, this is ALL THINGS CONSIDERED. I'm Robert Siegel.
A program such as ours is timed to the exact second, and occasionally, there are small holes when our mix of news and features doesn't quite fill up our two-hour slot.
So NPR's Joe Palca offered to come to our rescue with some short math and sciencey hole-filling stories, stories about what else - holes.
JOE PALCA, BYLINE: Today, we're going to talk about doughnut holes, those round things you buy in a bakery. To a baker, it's not a troubling question to ask whether you can turn a doughnut into a doughnut hole. Simple. Instead of shaping the dough into a tube and dropping it in the deep fat fryer, you shape the dough into a sphere and drop it in the deep fat fryer.
For a mathematician, the question is more complex. In the mathematical world, a doughnut is referred to as a torus. And mathematicians who study the algebra of shapes have been arguing for more than a century whether there was any way you could bend or twist or compress a doughnut-shaped torus so it would turn into a sphere. In 1904, the French mathematician Henri Poincare said the answer was no, but he couldn't show why with mathematical reasoning, and neither could anyone else until finally 100 years later, the less famous Russian mathematician Grigori Perelman did find a way to prove you can't turn a torus into a doughnut hole.
The moral of the story is if you want a doughnut hole, don't ask a mathematician, ask a baker. But if you want to know about the shape of the universe, the mathematicians who worry about doughnut shapes can probably help with answers.
With the help of our mathematically trained intern Anna Haensch, I'm Joe Palca, NPR News.
Copyright © 2013 NPR. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to NPR. This transcript is provided for personal, noncommercial use only, pursuant to our Terms of Use. Any other use requires NPR's prior permission. Visit our permissions page for further information.NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.Farmworkers harvest and package cantaloupes near Firebaugh, Calif.
Gosia Wozniacka/APAdvocates for farmworkers, especially those who grow America's leafy greens and fresh vegetables, are pushing the government to do more to protect those workers from exposure to pesticides.
A 20-year-old regulation — the Worker Protection Standard — is supposed to prevent harmful pesticide exposures on the farm. But activist groups like Farmworker Justice say it falls short, and the Environmental Protection Agency is currently working on a new version.
A new report from Farmworker Justice points out that under the current rules, farmworkers don't get nearly as much information about hazardous chemicals they may encounter as, say, factory workers. (Industrial workers are covered by different regulations, issued by the Occupational Safety and Health Administration.)
And then there's the barrier of language. Pesticides carry warning labels that spell out health risks and how workers should protect themselves — but those labels are usually in English. More than 80 percent of the workers in the "salad bowls" of Salinas, Calif., or Yuma, Ariz., are Hispanic. Many have difficulty communicating in English.
Farmworkers "are frustrated about their lack of knowledge about these chemicals," says Virginia Ruiz, director of Occupational and Environmental Health at Farmworker Justice. Her group, along with many others, submitted formal comments to the EPA arguing that "without bilingual labeling, today's Spanish-speaking agricultural workforce is at great risk for pesticide exposure."
Pesticide companies appear to be split on the issue. One industry trade association, Responsible Industry for a Sound Environment, has opposed bilingual labels, arguing that Spanish translations were unnecessary and would make labels more cumbersome to design. The agricultural chemical company Syngenta, on the other hand, endorsed the idea.
The proposed regulations face a long road before they'd ever take effect. Once the EPA finishes its draft, the document has to go through a review by the White House before it is even released for public comment. It could be years before the regulations are final.
In the meantime, though, some activist groups (including Farmworker Justice and Oxfam America) have joined forces with food companies (Costco!) to attack the problem on their own, through a new Equitable Food Initiative. The initiative is based on the idea that giving farmworkers more power, responsibility and money will lead to better, higher-quality food production.
The initiative has drawn up standards that (among many other things) are supposed to reduce the use of pesticides and share information — in any language — about how to handle them safely. On each farm, a worker-manager team is responsible for meeting the standard.
"The whole point is to get the team on-site to own this obligation," says Peter O'Driscoll, the initiative's project manager, who works with Oxfam America.
Researchers say it may be possible to temporarily reduce racial biases.
Images.com/CorbisIn the popular imagination and in conventional discourse — especially in the context of highly charged news events such as the shooting of Trayvon Martin — prejudice is all about hatred and animosity.
Scientists agree there's little doubt that hate-filled racism is real, but a growing body of social science research suggests that racial disparities and other biased outcomes in the criminal justice system, in medicine and in professional settings can be explained by unconscious attitudes and stereotypes.
Subtle biases are linked to police cadets being more likely to shoot unarmed black men than they are unarmed white men. (Some academics have also linked the research into unconscious bias to the Trayvon Martin case.)
Calvin Lai and Brian Nosek at the University of Virginia recently challenged scientists to come up with ways to ameliorate such biases. The idea, said Harvard University psychologist Mahzarin Banaji, one of the researchers, was to evaluate whether there were rapid-fire ways to disable stereotypes. Groups of scientists "raced" one another to see if their favorite techniques worked. All the scientists focused on reducing unconscious racial bias against blacks.
"Within five minutes, you have to do something to somebody's mind so that at the end of those five minutes you will now show a lower association of black with bad. And so this was run really like a competition to see which ones of them might work to reduce race bias and which ones don't," Banaji said.
The results were as surprising for what they didn't find as for what they did. Teaching people about the injustice of discrimination or asking them to be empathetic toward others was ineffective. What worked, at least temporarily, Banaji said, was providing volunteers with "counterstereotypical" messages.
"People were shown images or words or phrases that in some way bucked the trend of what we end up seeing in our culture," she said. "So if black and bad have been repeatedly associated in our society, then in this intervention, the opposite association was made."
Banaji, who has been a pioneer in studying unconscious biases, said she has taken such results to heart and tried to find ways to expose herself to counterstereotypical messages, as a way to limit her own unconscious biases.
One image in particular, she said, has had an especially powerful effect: "My favorite example is a picture of a woman who is clearly a construction worker wearing a hard hat, but she is breast-feeding her baby at lunchtime, and that image pulls my expectations in so many different directions that it was my feeling that seeing something like that would also allow me in other contexts to perhaps have an open mind about new ideas that might come from people who are not traditionally the ones I hear from."
This is the story of two continents doing battle, North America versus South America. It is also a biological mystery.
Robert Krulwich/NPR For a very long time, North America and South America were separate land masses. The Pacific Ocean slipped between them, flowing into the Caribbean. The Isthmus of Panama was there, but it was underwater. The two continents didn't touch.
As a result animals on both continents, especially mammals, evolved independently. They didn't, couldn't, interbreed. And yet, both North and South America had mountains, plains, long lazy rivers, deltas and supported similar forms of mammalian life. In fact, when biologists look back at the fossils, they found almost mirror like populations.
North America had horses. They were a little thicker and hairier back then.
Alex Tirabasso/Courtesy of Canadian Museum of NatureSouth America had a parallel version called "litopterns" with dangly Snuffleupagus-like noses.
North America had elephants and rhinos (gone now, but they once were natives).
Charles Douglas/Courtesy of Canadian Museum of NatureSouth America had Astrapotheres and pyrotheres, who looked quite similar, being tusk-bearing, water-friendly mammals.
North America had a saber-toothed tiger.
So did South America.
Again, while they looked the same, on close inspection you'd find the northern one carried its fetuses in a uterus, while the southern tiger was marsupial; its fetuses grew in an outside pouch.
"This evolutionary convergence was the greatest on land that the world has ever seen," writes biologist E.O. Wilson. The two continents had their own versions of shrews, weasels, cats and dogs. And then 2.5 million years ago, the two continents attached.
And Then There Was One ...
Long, long before any humans prowled the hemisphere, the Isthmus of Panama emerged, and all of a sudden it was possible for mammals in the north to meet (and compete) with mammals from the south.
So, as Ed Wilson puts it: "What happens when two full blown, closely similar dynasties meet head on?"
Well, it had to get rough. There was no accommodating everybody. Some of these animals lived in the same kinds of places and ate the same kinds of foods as their new competitors. The land couldn't support both, unless each side somehow managed to avoid the other.
Yet neither side had any obvious natural advantage. They'd survived and struggled to dominate their respective continents. Any gambler would have said, "I'm figuring half the time the northern mammals will prevail, half the time the southerners."
Which is why what actually happened is such a mystery.
Robert Krulwich/NPR According to Ed Wilson, "In general, where close ecological equivalents met during the interchange, the North American elements prevailed." In group after group, the southerners succumbed. Big cats with pouches lost out to big cats with none. South American toxodonts fell away, to be replaced by northern style tapirs and deer.
It wasn't a total rout. South American anteaters persist, so do tree sloths, monkeys. Armadillos have moved deep into Texas.
But overall, the northern mammals were better at invading and adapting. At this point nearly half the mammals in South America (if you count large groups, families and genera) come from lineages that came down from North America over the last 2.5 million years. The losers suffered a losers fate: they disappeared.
But why? What did the northern mammals have that the southern ones didn't?
"No one knows for sure," says Wilson. This is one of those puzzles that biologists keep coming back to, he says.
But they have a notion. The northern continents, America, Europe and Asia have spent eons attaching and detaching. Russia with Alaska, Canada with Greenland, Greenland with its eastern neighbors, Europe with Africa. Northern lands, therefore have regularly exchanged animals, and those animals have had to diversify, compete, adapt. They've had to deal with fierce winters and ice.
Robert Krulwich/NPR South America, on the other hand, since edging off from Africa, spent a long time as an island continent, untouched by other lands. And like Australia, it has produced highly unusual creatures, like kinkajous, guinea pigs, piranhas, weird frogs, toads, turtles, boa constrictors and tall, running birds like rheas — who can thrive because there aren't regular invaders to cope with.
What the northerners have that southerners lack, perhaps, is a tougher life. Northern animals have competed against more, different animals, accommodated more parasites, tested their immune systems in more ways; they've learned to expand more quickly, producing more babies when they need to — and it's that Northern worldliness, say some biologists, that gave them an edge.
But this is only theory. It's only begun to be tested. Thinking about it, I realized there is one southern mammal, a plains creature that stepped out of the southern forests that's been monstrously successful, spilling its offspring everywhere, north, south, east, west, even up...to the moon. We are that creature.
And while we weren't involved in the north/south encounter in the Americas, (we arrived later), technically, we are of African, that is southern, origin, so ... before biologists get too giddy about successful northern mammals, they might remember where they came from.
Just saying.
E.O. Wilson summarizes the North/South encounter in his book Letters to a Young Scientist. And special thanks to Carl Buell whose drawing of northern and southern big cats demonstrates, yet again, that he is king of paleo-illustration. I feel embarrassed to have my scribbles anywhere near his.
If you can't get to a beach this weekend, you can still see waves. Just look up.
Clouds, after all, are sculpted by waves of air. These clouds, in Birmingham, Ala., were formed when two layers of air — one fast, the other slow — collided at just the right speed to create rises and dips that caused the clouds to curl in on themselves and crash, just like waves on a beach.
They are called Kelvin-Helmholtz clouds. They don't last long, but they remind us that we live in a turbulent ocean of air. So too does this video, created by Simon Christen, who many mornings dragged his camera to a lookout high up in the Marin Headlands near San Francisco to watch a tide of Pacific fog come pouring in over the mountains, like a foamy, milky cascade. The air looks exactly like a wild sea.
But now comes an even more beautiful connection. Not only do clouds look like ocean waves, sometimes waves in the ocean help create clouds in the sky.
In his book, The Wave Watcher's Companion, Gavin Pretor-Pinney says that when waves come crashing down at a beach, creating that white, frothy foam, "the turbulence causes countless tiny air bubbles to form and burst, releasing a fine mist of water droplets into the air."
How Ocean Waves Build Clouds
When the water evaporates, what's left are microscopic bits of salt suspended in the air. (That's why the beach air tastes so salty.) As the air gets hotter, those bit of salt rise higher and become magnets for moisture.
Think of a little dot of salt moving up, up, up into the cooler wetter air. Bits of moisture cling to it as it rises, becoming droplets, the droplets begin to attach to each other, and before you know it, salt-seeded droplets are composing themselves into low-lying clouds.
The ocean, then, is seeding clouds in the sky!
(This doesn't mean you will see little clouds hanging above every wave-crashing beach. Nothing's that simple. What Pretor-Pinney is saying is that ocean waves produce some of the "condensation nuclei" that drift around the lower atmosphere, but the connection is real: Waves below can produce clouds above. That's why cloud spotters, though they may not realize it, are really wave watchers — tuning in late.
I like listening to "Stacey" and her friends as they shoot footage of the Kelvin-Helmholtz clouds in Alabama. They are amazed by what they see, ("They're going to think I'm crazy, because this looks like a wave!" "That's not why we think you're crazy, Stacey.") They want to call the local TV weatherman to figure out what's happening. They want to know what's going on.
This is the story of two continents doing battle, North America versus South America. It is also a biological mystery.
Robert Krulwich/NPR For a very long time, North America and South America were separate land masses. The Pacific Ocean slipped between them, flowing into the Caribbean. The Isthmus of Panama was there, but it was underwater. The two continents didn't touch.
As a result animals on both continents, especially mammals, evolved independently. They didn't, couldn't, interbreed. And yet, both North and South America had mountains, plains, long lazy rivers, deltas and supported similar forms of mammalian life. In fact, when biologists look back at the fossils, they found almost mirror like populations.
North America had horses. They were a little thicker and hairier back then.
Alex Tirabasso/Courtesy of Canadian Museum of NatureSouth America had a parallel version called "litopterns" with dangly Snuffleupagus-like noses.
North America had elephants and rhinos (gone now, but they once were natives).
Charles Douglas/Courtesy of Canadian Museum of NatureSouth America had Astrapotheres and pyrotheres, who looked quite similar, being tusk-bearing, water-friendly mammals.
North America had a saber-toothed tiger.
So did South America.
Again, while they looked the same, on close inspection you'd find the northern one carried its fetuses in a uterus, while the southern tiger was marsupial; its fetuses grew in an outside pouch.
"This evolutionary convergence was the greatest on land that the world has ever seen," writes biologist E.O. Wilson. The two continents had their own versions of shrews, weasels, cats and dogs. And then 2.5 million years ago, the two continents attached.
And Then There Was One ...
Long, long before any humans prowled the hemisphere, the Isthmus of Panama emerged, and all of a sudden it was possible for mammals in the north to meet (and compete) with mammals from the south.
So, as Ed Wilson puts it: "What happens when two full blown, closely similar dynasties meet head on?"
Well, it had to get rough. There was no accommodating everybody. Some of these animals lived in the same kinds of places and ate the same kinds of foods as their new competitors. The land couldn't support both, unless each side somehow managed to avoid the other.
Yet neither side had any obvious natural advantage. They'd survived and struggled to dominate their respective continents. Any gambler would have said, "I'm figuring half the time the northern mammals will prevail, half the time the southerners."
Which is why what actually happened is such a mystery.
Robert Krulwich/NPR According to Ed Wilson, "In general, where close ecological equivalents met during the interchange, the North American elements prevailed." In group after group, the southerners succumbed. Big cats with pouches lost out to big cats with none. South American toxodonts fell away, to be replaced by northern style tapirs and deer.
It wasn't a total rout. South American anteaters persist, so do tree sloths, monkeys. Armadillos have moved deep into Texas.
But overall, the northern mammals were better at invading and adapting. At this point nearly half the mammals in South America (if you count large groups, families and genera) come from lineages that came down from North America over the last 2.5 million years. The losers suffered a losers fate: they disappeared.
But why? What did the northern mammals have that the southern ones didn't?
"No one knows for sure," says Wilson. This is one of those puzzles that biologists keep coming back to, he says.
But they have a notion. The northern continents, America, Europe and Asia have spent eons attaching and detaching. Russia with Alaska, Canada with Greenland, Greenland with its eastern neighbors, Europe with Africa. Northern lands, therefore have regularly exchanged animals, and those animals have had to diversify, compete, adapt. They've had to deal with fierce winters and ice.
Robert Krulwich/NPR South America, on the other hand, since edging off from Africa, spent a long time as an island continent, untouched by other lands. And like Australia, it has produced highly unusual creatures, like kinkajous, guinea pigs, piranhas, weird frogs, toads, turtles, boa constrictors and tall, running birds like rheas — who can thrive because there aren't regular invaders to cope with.
What the northerners have that southerners lack, perhaps, is a tougher life. Northern animals have competed against more, different animals, accommodated more parasites, tested their immune systems in more ways; they've learned to expand more quickly, producing more babies when they need to — and it's that Northern worldliness, say some biologists, that gave them an edge.
But this is only theory. It's only begun to be tested. Thinking about it, I realized there is one southern mammal, a plains creature that stepped out of the southern forests that's been monstrously successful, spilling its offspring everywhere, north, south, east, west, even up...to the moon. We are that creature.
And while we weren't involved in the north/south encounter in the Americas, (we arrived later), technically, we are of African, that is southern, origin, so ... before biologists get too giddy about successful northern mammals, they might remember where they came from.
Just saying.
E.O. Wilson summarizes the North/South encounter in his book Letters to a Young Scientist. And special thanks to Carl Buell whose drawing of northern and southern big cats demonstrates, yet again, that he is king of paleo-illustration. I feel embarrassed to have my scribbles anywhere near his.
Farmworkers harvest and package cantaloupes near Firebaugh, Calif.Gosia Wozniacka/AP 
Researchers say it may be possible to temporarily reduce racial biases.Images.com/Corbis 
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Charles Douglas/Courtesy of Canadian Museum of Nature 
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