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				A Ticklish Question Alan learns we don't need people in order to be tormented by tickling.
		Select text to jump ahead in the clip: ALDA: Why do trees die? That's a really good question. ALDA: I'm visiting a nursery school... Olivia, what's your question? ALDA: to find out what's puzzling the preschool generation. What's your button question? Why are buttons round and not square? Why are buttons round and not square? That's a great question. Kids ask the greatest questions. Why don't all the seas run down to the bottom of the world? Why doesn't my dog talk? What's that little dangly thing at the back of my throat? How can Barney be on two TVs at once? As we get older, we either figure out the answers or, more often, simply stop asking the questions-- that is, unless you're a scientist and then a lot of those puzzling little questions we ask when we are young keep nagging away at your mind. In this show, we meet some of those scientists who go on worrying at life's little questions often coming up with some surprising answers. We're starting here on the campus of the University of California at San Diego with just the sort of question kids love to ask. How come you can't tickle yourself? Excuse me. I can tickle myself. ALDA: You can tickle yourself? Let's see. I tickle myself. ( everyone laughing ) Can you do it? And if you'll go ahead and have a seat right here in this screen... ALDA: Despite her being a grown up Christine Harris still wonders why we can't tickle ourselves. And she has devised, I'm told an ingenious experiment to help find the answer. If you agree to participate, you'll be tickled twice-- once by me and once by my machine. Oh, oh, look. Both times you'll be tickled on the bottom of your foot. I'll ask you to wear a blindfold and earplugs while we do this so you can attend to the sensation of tickle without distraction. So I'm just going to strap your foot in so it keeps it roughly in the vicinity of the machine. ALDA: Now, I had my suspicions that all is not quite as it seems here. But before I get a chance to check out the tickling machine any further... Does that feel snug, like it's not going to fall off? It could be a little snugger. Okay, how's that? Okay, so the first time I'm going to have my machine tickle you. So I'll press the button. It takes a few seconds for it to initiate and then it will turn itself off. ( button clicks ) ( machine whirring ) ( laughing ) That... ( laughing ) That was a machine? That was the machine. How much does that cost? Um, we'll tell you later. Okay, on a scale of zero to seven how ticklish would you rate that with zero not at all ticklish? Well, it must be seven. Okay, extremely ticklish. Now, this time, I'm going to tickle you and again, I'll ask you to rate it afterwards. Okay, how ticklish would you rate that? Um, ah, only around 5. 5 to six. I'm sorry to say. I mean, you know, you're a nice person, but... Okay, I'm just going to go ahead and take off your blindfold now. And you can take out your earplugs. So did you notice any difference between the sensation when I was tickling versus when my machine was tickling? Yeah, yeah, I noticed a big difference. Okay, in what way? The machine was more aggressive and relentless, presuming it was the machine. I was blindfolded, I couldn't tell. It was as if it was reaching inside my foot and wouldn't quit. And the second one was more courteous. Okay, okay, would you like to see the machine work now? Okay. Okay. So, and we can just leave you here. So basically I hit that, it takes a couple of seconds. ( Alda laughing ) You know, that alone is worth the price of admission just to see that. Hello, how are you? Nice to meet you. ALDA: Well now, tell me about this machine. It's a complete fraud, right? Yeah, we call it a mock tickle machine. "Mock" sounds better than "fraud. " And it just is a bunch of lights and "hold time," "sensitivity"-- things that we thought might look like a real tickle machine. Does anybody ever say, "That's a tickle machine? " Only one person figured out that it was not a real tickle machine. And what happened is the research assistant was under the table and she had her hair up in a pin and it got caught in the top of the table so there was actually this noise as she tried to free herself from under the table. What did you find out from this test? Well, basically, what we were looking at is nobody really knows why you can't tickle yourself, right? But one hypothesis is that it requires the belief that it's somebody else doing the tickling. And if that's the case then if you put someone in here with a machine and you tickle them with a machine they shouldn't laugh and smile. That's what we're interested in. Well, it sounds like I completely reversed what you expected. No, well actually I think you fit what I would expect. That's one hypothesis, and what I think is people who believe that tickling is something akin to a reflex or a fixed action pattern they would suggest that it shouldn't matter if it's a machine or a human-- that you should laugh and smile regardless of your beliefs. And so I think this does support that kind of thought. ALDA: The idea that a machine can tickle as well as a person certainly goes against most people's expectations. But in fact most of the subjects actually experiencing Christine's mock tickle machine were as tickled as I was if perhaps not quite as astonished. Still, the experiment has what seems to me an obvious problem. You haven't really tested for a machine tickling a person. You've tested only for whether the person believes a machine is tickling them. Mm-hmm. Have you ever had something like a machine to tickle them with? No, we haven't, because for us we wanted to test this assumption that there's something about these beliefs and for us, this was the right experiment. Because if you had the tickling machine-- a true tickling machine-- and you had it tickling the person and then you had a human tickling the person and you got a difference-- maybe the machine didn't cause laughter and smiling as much-- you would never know if it was because the tactile stimulation was different or if it was because the belief of the machine. So for us it was the right experiment. But we haven't actually built a real machine... Actually, it would probably be extremely difficult to build a tickling machine. ALDA: Difficult, but not, it turns out, impossible. In London, psychologist Sarah Blakemore recently built a robot that would tickle people's palms. It didn't look as much fun as Christine's mock machine but like hers, it did succeed in being tickly. So could you tell me how that stimulus felt on a scale from zero, meaning not at all to ten, meaning extremely tickly? About six. ALDA: What was clever about this experiment was that subjects could also control the robot themselves. And when they did, it stopped feeling tickly unless the robot had a built-in delay when the tickling sensation returned. So you can tickle yourself, but only indirectly. So you can feel the tactile stimulus on your hand now... ALDA: Sarah Blakemore then put volunteers into a scanning machine to see if there was any difference in how the brain responds to self-tickling as compared to machine tickling. I'll put you into the scanner. ALDA: The experiment suggests that the brain has a self-censor-- a damping signal sent from the region monitoring movement to the region reacting to touch... a useful survival mechanism making sure we don't jump in surprise every time we touch our own bodies. So that's why we can't tickle ourselves. Our brains won't let us. But there's another little question about tickling. How come it makes us laugh? Is it because we find it funny-- funny in the same sense we find humor funny? No less an authority than Charles Darwin suggested a link between ticklish laughter and humorous laughter so Christine Harris set up another experiment. TV announcer: We will work with the customer to give that customer the change that he or she needs. ALDA: Her idea was to exploit what comics call "the warm-up effect. " It takes a joke or two to get the audience in the right mood. If you come to us with a hundred-dollar bill we're not going to give you 2,000 nickels unless that meets your particular change needs. ALDA: If ticklish laughter and humorous laughter are the same then warming someone up with a funny video should also make them more ticklish. We will give you the change equal to the amount of money that you want change for. So at what point do you tickle her? So after she's watched the video and laughed and smiled at the video then we do the tickling and so Noriko... We're going to tickle you anywhere from the underarms to the waist so if you'll just kind of loosen your arms... Should I sit up? You can lean back but just let your arms fall kind of loose. Yeah, okay. ALDA: Margaret certainly didn't seem very amused. HARRIS: Okay. I'd say that was about a two, maybe. First of all, do you find that people are warmed up by watching the video? No, actually we didn't find an effect of warm-up. So if you've just watched a nature film or you've just watched a comedy it doesn't affect how much you laugh and smile in response to tickling. And vice versa, if you are tickled and then watch a funny film it doesn't increase the amount of laughter. Did it seem similar to you, to the laughter you had when you were laughing at the tape? MARGARET: Not at all. No, it didn't seem humorous to me. I mean, the squirmy feeling is the reaction but it wasn't the same sensation evoked by the video. ALDA: Which brings us to the biggest little tickle question of all: Just why are we ticklish? Christine Harris thinks it might help develop combat skills... I got you, I got you. Adam, I got you. ALDA: The laughter keeps the tickler tickling even while the tickled is trying to escape. HARRIS: It looks like you're having the time of your life. You look like you're loving it-- laughing, smiling-- but a lot of people don't actually like to be tickled. Do you? No, I don't. I don't, no. ( laughing ) You don't seem to like to talk about it. Okay, we've got another experiment for you.

				Laughing Matters Think you only laugh when something’s funny? Think again.
		Select text to jump ahead in the clip: This has to do with the little boxes on your desk. Ready? Okay, push the button. ( boxes laughing ) ALDA: All that tickling got us thinking about laughing. So we dropped in on Bob Provine's class at the University of Maryland with another of our deceptively simple little questions. Just what is laughter? Okay, well, I think it's undeniable that laughter is a really powerful sound. You know, it makes you... you didn't decide to laugh you just laughed when you heard the laughter. There's something special about that sound. ( laughing hysterically ) ALDA: Laughing just happens to be one of my favorite activities so I'm more than happy to provide a laugh for Bob's computer. Okay, notice how much more regular that was than with speech. So as I speak into the computer here we see this is a very irregular pattern as opposed to those regular hills and valleys that were separated by regular intervals when we laughed. For example... ( laughing ) ALDA: Bob Provine, as you've probably guessed by now is a laughter expert. Have you seen anybody about that? Uh... I'm... There's no known treatment for it. ( Provine laughing ) ALDA: He's listened to laughter from cultures around the world and always finds this characteristic pattern of regular peaks and valleys. ( Provine continues laughing ) PROVINE: And in fact, it's very difficult to laugh in other than that way. For example, could you try to laugh really fast? Laugh really fast. High-speed laugh. ( cackling ) Okay, we still have the peaks and valleys. But that's not that much faster than what we were doing-- try to laugh faster. Uh... ( forcing faster laugh ) That's a little sinister there. Try it once more. ( Alda cackling ) I'm not too proud to do this, so you don't be. ALDA: Provine argues that not only is human laughter highly stereotyped-- it also sets us apart from all other animals. The chimpanzee laughter is like this: ( imitating panting laughter ) ( students laughing ) PROVINE: And in fact, if you were tickling a chimpanzee and rolling around in a little rough-and-tumble play which, in fact, we've done as part of our research... ( chimpanzee panting ) that chimpanzee will perform what's called a play face and make that sound. And you would be absolutely convinced that that is laughter even though the sound's a bit different. But the sound is not just different; it's a difference in a way that makes a huge difference. It's a difference that reveals to us why we can talk and why chimpanzees can't. You know, when I laugh, I'm going ha, ha, ha, ha. I'm chopping an outward breath. ALDA: Right. Well, chimpanzees don't do that and can't do that. And why? Chimpanzees laugh by going: ( imitating panting chimpanzee ) Their laughter is locked in to their cycle of breathing. So it's both in and out. Yeah, it's in and out. And they can't chop off an expulsion of air they can't take an exhalation and chop it into discrete bits. Yeah, that's exactly... The way we can. What is there about us that enables us to do that? Well, I was puzzling about this for a long time. And our most recent work has indicated that it's being able to stand upright and walk on two legs. ALDA: When a four-legged animal walks or runs its breathing is literally locked in step with its stride. Only humans, Provine argues whose forelimbs no longer support weight can breathe freely. So the ability to stand up-- however that derived-- also conferred on us the freedom for our lungs to now be directed... used in other ways. I mean, was that automatic? Did you... do you suppose people automatically started laughing? "Ho-ho, look at this, ho-ho! " I mean, how did you get from being able to stand up, do you suppose to actually producing these staccato sounds? Being able to walk upright on two legs is the necessary event but not sufficient. So when you walk upright on two legs this means that there can be selection for the fancy sound-making we call speech. ( recording of Alda laughing ) ALDA: So according to Provine, the regular sounds of laughter allowed our ancestors gradually to evolve the irregular patterns of speech. ( laughing continues ) A nice idea. But what's laughter for today? Laughter is really not about jokes it's not really about comedy... Now you tell me. ( laughing ) It's about the relationships between people. ALDA: Laughter, he argues, is a sort of social lubricant occurring 30 times more often when people are in groups than when they're alone... We always laugh together. ALDA: and often for no obvious reason. Laughter is an unconscious response and we don't have conscious control of it. You know, good actors can simulate a laugh. But like you can't cry on command most people can't laugh on command and it's very apparent when they do so. Laugh? ( weak laughter ) Oh my God, that was funny. ( forced laughter ) There we go-- thank you. In fact, if you ask a person to laugh the first response will be, "Well, I can't laugh on command" or "I can't laugh just because you ask me to. " Just make yourself laugh, huh? INTERVIEWER: Yeah. I guess I can't do it. Laugh? INTERVIEWER: Just laugh. Just for any reason. All right, um... I've got to think of something funny now. Well, you see, we're Canadian. Yeah, we're Canadian, we're not able to spontaneously laugh like that. That's right, you know, quiet, reserved. And of course, after that they may laugh... ( abrupt forced laughter ) They're laughing then not because you asked them to. They're laughing because of some social glue they're hoping to exude. Someone make a joke or something. ALDA: And then there's another kind of laughter-- the nervous giggle that can inflate to the verge of hysteria. I can't laugh very well. I saw somebody laughing for half an hour because we were right next to the cliff. And it was just... ( imitating hysterical laughter ) "What's the matter? " ( hysterically ): "Nothing, I'm fine. " Or seeing a snake, you know? ( hysterically ): "It's a snake-- there's a snake. " "Are you okay? " "No, I'm fine, it's just a snake, I'm okay," you know? Now, that sounds like it's taking us back a good 200,000 years or a million years to somebody who's upright and scared. I think that we overestimate how rational, how reasonable we are. And in laughter we're penetrating beneath that veneer of civility and language and rationality into something that's very primitive, very deep and we share with all other animals. So just as we go to the zoo and hear other animals make various calls and cries when we examine our own laughter it's exactly those kinds of sounds. ( chimpanzee laughing ) ( laughing maniacally ) The questions pop into our heads every time it happens. Along with that unexpected sneeze

				Cold Comfort Some cold remedies may be all in your head.
		Select text to jump ahead in the clip: or the suddenly scratchy throat we wonder, "How did I catch it this time? "How bad is it going to be? "Should I take some vitamin C, suck a lozenge drink some herbal tea? " And then there's the big one. If scientists can send a man to the moon or invent the Internet or peer at distant galaxies, why can't they cure the common cold? Well, I've come here to Charleston, South Carolina, to find out. Because Charleston is about to experience a sudden mini-epidemic, an outbreak of runny noses and stuffy heads that could take us one step closer to an answer. What's unusual about this outbreak of colds is that it didn't just happen. WOMAN: Okay, put it in the cup. ALDA: These volunteers, whose noses are being rinsed out with a saline solution are being paid to catch a cold. If you wash his nostrils out he'll have a better chance of catching cold? Mm-hmm, because the nose will be nice and clean. This is a horrible thing to learn first thing in the morning. Okay, go ahead. ( chuckling ) I mean, I would have thought that getting your nose clean-- you know, like they say "Keep your nose clean"-- I would think that would help. ALDA: The man dispensing the colds is Ronald Turner an old hand at conducting studies on candidates for cures. What he's carefully placing up the nostrils of his volunteer subjects is a strain of rhinovirus one of the commonest causes of the common cold. Now you already had one of these? WOMAN: I had one-- I had one already. So how many do you give? Two-- we just go around twice. You really want to make sure you make these poor people sick. All right, this is the same as before, okay? ALDA: Actually, Ron Turner is hoping some of his volunteers won't get sick. Because for the last two weeks some of them have been taking twice-daily doses of one of those herbal extracts that a lot of us believe helps fend off or shorten a cold. Some of them are getting active medication some are getting placebo, but everybody gets the virus. Do you know, are you aware of who's getting the placebo and who's getting the medication? No, no, we're all blinded. You don't have any idea? Uh-uh. MAN: This is what they look like. ALDA: The famous Jujube medication. MAN ( laughing ): Yeah. So what do you think is in there? I'm really not sure. Hopefully some medication that will take care of me. But... for all I know it could just be sugar pills. ALDA: This need to ensure that no one knows who's getting what is absolutely critical in a trial like this. These are your pills for the next five days. ALDA: It's especially important that the volunteers aren't picking up any clues from how the pills taste or make them feel. Do you think you were getting the active medication or the inactive medication? I think I was getting the inactive. I have no idea, I really don't. No, I had no side effects no symptoms of any kind either way, so... WOMAN: Okay, if you had to give me a guess? Active. Inactive. I think I was getting inactive. Active. WOMAN: And why? I don't know-- It was just that whenever I took it I felt, like, fuller. I'll have to say the active medication. WOMAN: Why would you say that? It'd kind of depress me if I was having the other medication. I would say the inactive. WOMAN: Why would you say that? Just because I didn't feel any difference. Do you think it matters whether or not you believe you're taking the active ingredient? Yes. I think if I thought I was on it I would definitely experience a placebo effect and feel better than maybe I should. And thinking that I'm not on the medication I might be more inclined to feel the symptoms more severely. ALDA: Lindsey's right. If people are able to figure out what they're getting then it could dramatically influence the results of the trial. I'll go with active. WOMAN: Why do you say that? I'm hopeful. ALDA: In fact, in Ron Turner's opinion many of the clinical trials of popular cold remedies are fatally flawed by this very problem. His list includes even that old stand-by, vitamin C +and, distressingly, two of my personal favorites-- zinc lozenges and Echinacea. He's tested both in carefully controlled trials like his current one and found they don't work. All right, I've got one left. ( both laughing ) If you kill this, I'm never going to be able to fight off a cold again. Vitamin E. Well, vitamin E is interesting and we actually have looked at vitamin E as well. There's some biologic rationale for vitamin E and for vitamin C, for that matter in the sense that they are both antioxidants, and we do think that oxidative stress in the cell has something to do with production of the symptoms of the cold. And so we did a study of vitamin E where we gave vitamin E supplements for a couple of weeks to a group of volunteers. We drew blood from them. We showed that the vitamin E levels in their blood were substantially higher than in the placebo group and then we challenged them in our model with our virus and had absolutely no effect. So it... it was no good as a prophylactic, but... Or as a treatment. Or as a treatment either? Right. I'm dead. ( Turner laughs ) That's it, I've got nothing left. Well, the good news is that you'll get over your cold anyway. Definitely have the cold... I have it. I don't feel ill at all. If I'm supposed to be ill, I'm not. I have the cold. ALDA: Three days have passed since our volunteers were infected with the cold virus. They've been reporting in every morning since. WOMAN: It's been about 72 hours since the inoculation. Do you think you received a cold? Yeah, I do-- I definitely had it yesterday. Okay, I want you to rate your symptoms this morning based on the severity since your last visit. Any symptoms of sneezing? I'd say about a two. Okay, runny nose? One. Nasal stuffiness or obstruction? Ah, two. Cough? One. ALDA: There are a dozen symptoms on the list-- enough to get a pretty objective measure of the severity of the cold. Definitely getting a little worse, huh? Yes. You can go back and get your nasal wash. ALDA: The nasal wash will reveal how strongly the virus took hold. WOMAN: Good morning. Good morning. ALDA: Meanwhile, we wondered how our volunteers feel now about whether they are on the test medication or the placebo. YOUNG WOMAN: I think I'm receiving just a placebo. I think it kind of got better because I was taking... I'm not sure whether I was taking that medication or not but I think I did. I believe I had the inactive medicine. Because otherwise I think I probably wouldn't have gotten the cold or it wouldn't have been as severe. Based on how mild my symptoms are I think maybe I did get the active. Oh, yeah, I'm really glad I got it. Because I'd be walking around with tissues hanging out of every pocket and just not a pretty sight. I think I got the inactive medicine because I've been getting worse as the days go on. I guess I got the active medication because all I've had is a runny nose and that's it. ALDA: Perhaps not surprisingly most of those with the worst colds thought they were on the placebo while most subjects with mild colds guessed they had the medication. But in fact, it was all in their heads. Later, when who got what was matched up with the severity of their infections there was no difference between those who got the test substance and those who didn't. That's right. The mystery herbal ingredient in those big brown pills did nothing in Ron Turner's study-- joining on his hit list Echinacea, zinc lozenges and vitamin E. You know what's funny about this? And this is just... totally personal. I'm going to keep taking this stuff because I haven't got any other... any other feeling of control over the cold. And for me, getting a cold-- because I have to use my voice in my work-- it's something that I'll... I'll clutch at straws over. How does that strike you as a scientist? Well, I guess I don't have any problem with that. As I said, my job here is to try to figure out whether there is a biologic effect. Whether people choose to use that information or whether they get some benefit-- whether it's psychological or mental-- that's fine. You know, the saying is, of course that if you take this medicine you'll get over your cold in seven days and if you don't it will take a week. ( chuckles ): So... That's the best you can come up with after all these years? Well, I think we're doing better than that. I've heard that joke. I think we're doing better than that. ALDA: One way in which science may at last be doing better is in attacking cold viruses themselves. A big reason the common cold hasn't been cured in the past is that so many different viruses can cause it. And for many, many years people thought that that was going to make it impossible to develop therapy for the common cold. ALDA: Yeah, that's what I've read, constantly is that there are too many colds to be able, too many viruses to be able to find something common in all of them. Right, and I remember when I first started on this project somebody who I, that I was good friends with in college who... we diverged slightly-- he went into medicine and I went into basic biochemistry-- I told him I was working on this and he laughed his head off at me and he said, there are over a hundred serotypes. No one will ever do that. Now your friend is giving out antihistamines and you're solving the common cold. Probably, yeah. ALDA: Steve Worland's company, Agouron is trying to attack the commonest group of cold viruses the rhinoviruses. Their target is actually a protein called protease that all rhinoviruses use to make copies of themselves. The company started by making tiny crystals of this crucial protease then used an X-ray crystallography machine to get a precise three- dimensional picture of it. MAN: ... you can actually look down and you can see the tip of the loop. The crystal is very small only a couple of tenths of a millimeter. What we're seeing here is an electronic image of the, uh... ALDA: Now, there are moments when we're making Frontiers when we get just a little out of our depth. ALDA: What do you do, roughly to get a three-dimensional picture from those dots? Well, basically what we do is we use computers to carry out a three-dimensional Fourier summation uh... and the individual coefficients in that Fourier series are related to the intensities that we're measuring here. And that's the rough version. ALDA: Okay, well, once they did that, this was the result: a 3-D image of the protease the virus needs in order to replicate itself in our nose cells. WORLAND: That was enough to say that there are regions where the protein goes in rather than comes out where we could then plug in, if you will, our drug molecule. Now, the reason you want to plug your drug molecule in is if you don't do that this is going to be a place where the protease is going to hook up with what it needs to hook up with to do its work and help the virus replicate. That's precisely right. ALDA: The drug molecule Agouron designed which nestles neatly into the critical protein successfully stops the virus from replicating in a test tube. The next step was to try it in noses. Good morning, everybody. ALDA: In a clinical trial very similar to the one Ron Turner ran the antiviral drug was tested on college students at the University of Virginia-- except that here, the subjects got to stay in a hotel. 24 hours after getting infected they received several daily doses of the experimental drug in a nasal spray. Here, too, some of the subjects got a placebo spray instead of the real thing. Do you feel generally bad? I feel like I got a cold. Okay, that's what I need to know. ALDA: The severity of their colds was judged by questionnaire by measuring the virus directly and by weighing the tissues they used. And the results were promising-- a significant reduction in cold symptoms among those on the drug. How you feeling this morning? I'm feeling fine. No cough, no sore throat, no nothing? Nothing. All right, that sounds good. ALDA: Even though the drug seems to work getting it to market will be far from easy. It will have to be cheap, it will have to work fast and, as Steve Worland knows only too well it will have to be completely safe. It's a real drag to have a cold, but it's not life-threatening. In that case, we're even more concerned about a safety burden because we're not treating something like cancer or HIV where a certain degree of side effects traded for saving somebody's life that person would almost always say, "I'll take it. " It's not worth trading a serious side effect to get rid of a cold. So this really has to be a compound that has virtually no side effects or people are just going to elect not to choose it. If you tell people, "Well, you know you're going to feel numbness in your hands" for, just as a hypothetical example "but your cold will go away" most people will say, "I'll take the cold.

				Why Are Peppers Hot? A chemical called capsaicin makes chili peppers burn our mouth. But scientists discover it can also help ease pain by dulling nerve endings.
		Select text to jump ahead in the clip: IT'S GOOD TO KNOW SCIENTISTS ARE TRYING TO SOLVE THE REALLY BIG MYSTERIES OF LIFE: HOW DID LIFE BEGIN? WHEN WILL THE UNIVERSE END? WILL WE EVER MAKE A ROBOT THAT'S SMARTER THAN WE ARE? NOW, WE LIKE BIG QUESTIONS AS MUCH AS THE NEXT SCIENCE SHOW BUT THIS TIME, WE'VE SET OUR SIGHTS FIRMLY ON THE TRIVIAL-- ON THE FASCINATING LITTLE QUESTIONS THAT CROP UP IN EVERYDAY LIFE. EXCEPT WE GOT A SURPRISE-- WHICH MAKES US WONDER IF THERE ARE ANY TRULY TRIVIAL QUESTIONS IN SCIENCE BECAUSE, AS WE QUICKLY DISCOVERED ONE THING JUST KEEPS LEADING TO ANOTHER. TAKE THE FIRST QUESTION WE ASKED. IT'S WHY WE'RE HERE IN SANTA FE, NEW MEXICO AT A FOOD FESTIVAL THAT CELEBRATES WHAT'S PRACTICALLY THE STATE FOOD-- THE CHILI PEPPER. THE QUESTION IS OF GREAT PERSONAL INTEREST TO ME BUT IT ISN'T ONE YOU'D IMAGINE LEADING TO A MEDICAL BREAKTHROUGH. SO, HERE'S THE QUESTION: WHY ARE PEPPERS HOT? WELL, WHY ARE THEY HOT? CHILIS ARE HOT BECAUSE THEY HAVE A COMPOUND OR A SET OF COMPOUNDS, CALLED CAPSAICINOIDS THAT'S FOUND INSIDE THE FRUITS ALONG THE PLACENTA. AND CONTRARY TO A LOT OF BELIEFS THE WALLS HAVE NO HEAT, THE SEEDS DON'T HAVE ANY HEAT. THEY'RE ONLY IN THIS ONE LITTLE AREA HERE JUST WHERE THIS ORANGE COLORING IS. THAT IS THE CAPSAICINOIDS. SO THE MORE ORANGE, THE HOTTER THE CHILI. WE THINK IN NATURE, THE PLANT EVOLVED THIS TO KEEP MAMMALS FROM EATING THE FRUITS BECAUSE WHEN THE SEED PASSES THROUGH A MAMMAL'S DIGESTIVE TRACT, THEY'RE DESTROYED. AND SO... BUT BIRDS CAN COME ALONG PICK THE FRUIT OFF, EAT IT AND THEN SPREAD THE SEEDS AND PUT LIKE A FERTILIZER PELLET WITH IT. SO THE... THE CAPSAICIN IN PEPPER WHICH TASTES SO HOT TO US AND TASTES SO GOOD TO ME IS REALLY TO KEEP ME FROM EATING IT, HUH? EXACTLY. IT'S TO KEEP MAMMALS AWAY AND GET BIRDS TO CONCENTRATE ON THEM BECAUSE THAT'S HOW THE SEED SPREADS? EXACTLY-- THE BIRDS DON'T TASTE CAPSAICINOIDS; THEY DON'T SENSE THE HEAT. WHAT THEY'RE DOING IS GETTING A VERY GOOD SOURCE OF VITAMIN A. Man: THE FLAVORS AND THE AROMAS ARE WHY THE WORLD'S CUISINES HAVE GONE TO CHILI PEPPERS. IN OTHER WORDS WITHIN A HUNDRED YEARS AFTER COLUMBUS BROUGHT BACK THE FIRST CHILI PEPPER SEEDS FROM THE NEW WORLD THEY SPREAD TO THE OLD WORLD AND COMPLETELY WENT AROUND THE WORLD IN LESS THAN A HUNDRED YEARS. AND WHAT WOULD CURRIES BE LIKE WITHOUT CHILI PEPPERS? WHAT WOULD THAI FOOD BE LIKE WITHOUT CHILI PEPPERS? I KNOW, I THINK OF SZECHUAN FOOD ONE OF MY FAVORITE FOODS-- I CAN'T IMAGINE IT WITHOUT CHILI PEPPERS BUT THEY ATE THERE WITHOUT CHILI PEPPERS FOR THOUSANDS OF YEARS, I GUESS. DeWitt: THOUSANDS OF YEARS. Alda: MY HOSTS' PLAN IS FOR ME TO SAMPLE SOME OF THE DIFFERENT PEPPERS HERE SO THAT I CAN APPRECIATE THEIR SUBTLETIES. BUT FOR ME, SUBTLETY AND PEPPERS DON'T MIX SO OFFERED A CHOICE OF MILD, MEDIUM OR HOT... Alda: LET'S GET HOT RIGHT AWAY. OKAY, THIS IS THE CAPSICUM PICATUM. I'LL LET YOU TRY THIS. ALSO KNOW AS AJI IN SOUTH AMERICA. IT'S GOOD. NOW, YOU SAID YOU LIKED HOT PEPPERS. YES, I DO. AH! Alda: I'M NOT THE ONLY ONE HERE PLAYING WITH FIRE. Alda: WHEN SOMEBODY EATS A PEPPER THAT'S TOO HOT FOR THEM WHAT DO YOU RECOMMEND TO CALM DOWN THEIR MOUTH? WELL, THERE'S A LOT OF FOLK REMEDIES. PEOPLE SAY THAT IF YOU EAT SUGAR OR IF YOU DRINK A LOT OF BEER, YOU WON'T CARE HOW HOT IT IS. BUT MOSTLY IT'S DAIRY PRODUCTS THAT HELP YOU AND THE THICKER, THE HEAVIER THE DAIRY PRODUCTS, THE BETTER-- LIKE YOGURT, FOR EXAMPLE, IS GOOD. SOUR CREAM IS VERY, VERY GOOD AND THAT'S ONE OF THE REASONS SOUR CREAM IS SERVED WITH ENCHILADAS OUT HERE IN NEW MEXICO. WE'RE GOING TO MAKE YOU INTO A CONNOISSEUR AFTER THIS... Alda: PAUL AND DAVE ARE STILL DETERMINED TO TEACH ME THE FINE ART OF PEPPER TASTING. BUT I GET THE HORRIBLE FEELING IT'S ALREADY TOO LATE. THE THREE AREAS TO LOOK FOR IS THE FRONT OF YOUR MOUTH, MID-MOUTH OR BACK OF THE THROAT, THAT THROAT AREA. TASTES LIKE OATMEAL-- I DON'T TASTE ANYTHING. OH, WELL, WE BURNED YOUR TASTE BUDS ON THOSE HOT ONES, SO... WELL, LET'S TRY THIS ONE. LET'S SEE WHAT HAPPENS HERE. IT'S A LITTLE HOTTER, NOW. OKAY. TOMATO SAUCE. OH! WE BURNED YOU OUT, AND IT MIGHT BE SEVERAL HOURS BEFORE YOUR PALATE GETS BACK TO NORMAL. WHY ARE WE IN THIS RED LIGHT LIKE THIS? Alda: BURNED OUT MY PALATE? THIS SOUNDS SERIOUS, WHICH IS WHY I FIND MYSELF SITTING IN A VERY STRANGE ROOM IN BALTIMORE. THIS IS VERY FUTURISTIC. YES, IT IS. OH, LOOK, THERE ARE LITTLE SCREENS DOWN THERE. Alda: I'VE COME HERE TO CHECK MY HEAT-SENSING ABILITIES AGAINST SOME OF THE BEST-TRAINED TONGUES IN THE WORLD BELONGING TO THE MEMBERS OF THE PEPPER-TASTING PANEL AT ONE OF THE NATION'S LARGEST SPICE COMPANIES, McCORMICK'S. SYLVIA KING IS IN CHARGE. EVERYBODY GET SET, AND GO. Alda: WE START WITH WHAT'S RECKONED TO BE A MILD SOLUTION OF THE HOT-PEPPER CHEMICAL CAPSAICIN. SWALLOW. Alda: WE'RE INSTRUCTED TO ASSIGN IT A FIVE ON A HEAT SCALE OF ZERO TO 15. SO IS EVERYBODY READY? GO AHEAD AND RINSE WITH WATER AND RINSE WITH A CRACKER. Alda: A CRACKER, HMM. WHAT HAPPENED TO THE SOUR CREAM? SO DOES THE CRACKER REALLY CLEAR OUT THE SENSATION OF, UM... IT WILL HELP. OF HEAT? King: GET READY FOR YOUR STRONG REFERENCE. Alda: THE IDEA HERE IS TO TUNE OUR TONGUES TO A STANDARD SET OF HEATS CONCLUDING WITH A DOSE OF CAPSAICIN SCORING A RESPECTABLE 13 ON THE HEAT SCALE. SWALLOW. AH! ( coughs wheezily ) SMOOTH. Alda: OKAY, WITH OUR TONGUES NOW CALIBRATED IT'S TIME TO SEE HOW WE ALL RATE A SAMPLE FROM A REAL HOT PEPPER-- WHICH IS WHY, BY THE WAY, THE LIGHT'S RED: TO DISGUISE THE SAMPLE'S COLOR SO IT WON'T INFLUENCE OUR SCORE. GO. Alda: I'LL GIVE IT AN EIGHT. AND MY FELLOW TONGUES? I WOULD GIVE IT ABOUT A 7. 9. 7.5. ABOUT A SEVEN. 7. 2. ABOUT A 7. 6. Alda: WELL, THAT'S A RELIEF-- MY TONGUE SEEMS TO BE RIGHT IN LINE WITH THE EXPERTS'. 7. 8. SEVEN. ABOUT AN 8. 2. I'M SORT OF AMAZED THAT I EVEN COULD TASTE ANYTHING IN THE MILD ONE, YOU KNOW. I MEAN, I WAS REALLY AFRAID WHEN I CAME IN THAT YOU'D SAY, "THIS IS THE MILD ONE" AND I'D SAY, "NO, THAT'S THE WATER. " ( King laughs ) Alda: OF COURSE, THE SPICE COMPANY DIDN'T SET UP THE HEAT-SENSING PANEL JUST FOR MY PEACE OF MIND. IT'S ONE OF SEVERAL WAYS THEY CHECK THE HEAT OF ALL THE PEPPERS THEY BUY SO THAT THEIR CUSTOMERS DON'T GET A NASTY SURPRISE ONCE THE PEPPER IS GROUND INTO POWDER OR FLAKES. STILL, HEARTENED THAT MY TONGUE HAS SURVIVED YEARS OF HOT-PEPPER PUMMELING, I TOOK IT TO A SPECIALIST. SO IF I CAN TASTE THIS AS EXTREMELY BITTER, I'M A... A SUPERTASTER. I'M A SUPERTASTER, AND IF I CAN'T TASTE ANYTHING... IF IT TASTES LIKE PAPER TO YOU YOU'RE A NON-TASTER. AND IF IT'S SOMETHING IN THE MIDDLE YOU'RE A MEDIUM TASTER. BE SURE THE PAPER GETS REALLY MOISTENED WITH YOUR SALIVA AND MOVES ALL AROUND SO IT COVERS YOUR WHOLE TONGUE. ARE YOU TASTING ANYTHING? IT'S BITTER. AH, YES, YES. AUTHENTIC SUPERTASTER. IT'S REALLY BITTER... OH! UH-OH, ALL RIGHT. I THINK NOW'S THE TIME TO TAKE IT OUT. IF I'M NOT A SUPERTASTER, I DON'T WANT TO KNOW. THIS IS CLOSE ENOUGH. OKAY. Alda: ONLY ONE PERSON IN FOUR IS A SUPERTASTER. I CAN'T SHARE THAT EXPERIENCE WITH YOU BECAUSE I'M A NON-TASTER. Alda: WHILE ANOTHER ONE IN FOUR, LIKE LINDA DOESN'T TASTE THE PAPER AT ALL. THE PAPER WAS ONLY THE BEGINNING OF MY TONGUE CHECK-UP. NEXT CAME BLUE FOOD COLORING. OKAY, SWALLOW. MOVE YOUR TONGUE IN YOUR MOUTH A COUPLE TIMES AND SWALLOW A COUPLE TIMES AND THAT WILL DISTRIBUTE THE DYE. AND THEN WE WILL HAVE A LOOK. STICK YOUR TONGUE OUT. OH, MAGNIFICENT-- THE STAINING IS ABSOLUTELY PERFECT. I CAN SEE THE PINK FUNGIFORM PAPILLAE. YOUR TONGUE LOOKS LIKE IT'S TILED IN FUNGIFORM PAPILLAE. YOU DEFINITELY LOOK LIKE A SUPERTASTER. ( lisping ): I'M A SUPERTASTER. ( Bartoshuk chuckles ) Alda: THE FUNGIFORM PAPILLAE ARE LITTLE SPROUTS ON MY TONGUE. EACH ONE HARBORS A HALF DOZEN OR SO TASTE BUDS WITH NERVE FIBERS CONNECTING THEM TO MY BRAIN. WHILE SOME OF THESE FIBERS CONVEY THE SENSE OF TASTE MOST OF THEM DON'T SENSE TASTE AT ALL, BUT PAIN-- WHICH BRINGS US BACK TO HOT PEPPERS. YOU ARE FEELING WAY MORE PAIN FROM EATING A RED PEPPER THAN I WOULD, FOR EXAMPLE. BECAUSE I HAVE MORE OF THESE STRUCTURES. THAT'S RIGHT, YOU HAVE WAY MORE PAIN FIBERS SO YOU PERCEIVE WAY MORE PAIN. THIS IS REALLY WEIRD BECAUSE I EAT FAR MORE RED PEPPER ON MY FOOD THAN ANYBODY I KNOW. Alda: NOW, OF COURSE IT MAY BE THAT I JUST LIKE PAIN MORE THAN MOST PEOPLE BUT THERE'S ANOTHER EXPLANATION WHICH GOES BACK TO THAT HOT PEPPER I ATE IN SANTA FE BECAUSE IT NOT ONLY KNOCKED OUT MY SENSE OF TASTE; AFTER THE INITIAL BURN, IT ACTUALLY NUMBED THE PAIN FIBERS THAT NESTLE AROUND MY TASTE BUDS. NOW THAT THIS HAS COOLED A LITTLE, I PUT THE PEPPER IN? Alda: WHICH IS WHY I'M HELPING MAKE HOT-PEPPER CANDY. A DASH OF CAYENNE PEPPER BEFORE THE TRADITIONAL TAFFY PULL... MY THUMB JUST STUCK TO THIS... AH, THERE WE GO. BOTH THUMBS, I HAVE BOTH THUMBS IN THE TAFFY. Bartoshuk: HERE'S SOME. Alda: AND THE RESULT IS A CANDY THAT LINDA BARTOSHUK USES TO TREAT PATIENTS WITH PAINFUL MOUTH SORES. THE CANDY WAS THE IDEA OF A STUDENT OF HERS BUT OTHERS HAD THOUGHT OF IT BEFORE. IF YOU GO BACK AND READ ACCOUNTS OF AZTEC MEDICINE YOU'LL FIND OUT THAT THE AZTECS WERE USING CHILI PEPPERS MIXED WITH HONEY TO TREAT SORES IN THE MOUTH. MY GUESS IS THAT EVERY CULTURE THAT'S EVER CONSUMED THESE CHILI PEPPERS HAS FIGURED OUT THAT THEY'RE REALLY GOOD ANALGESICS. WE'RE JUST THE LAST IN A LONG LINE OF PEOPLE WHO HAVE LOOKED AT THAT. Alda: ONE MAN WHO'S HAPPY THAT RESEARCHERS ARE AGAIN EXPLORING THE PAIN-KILLING PROPERTIES OF PEPPERS IS A LONG-TERM SURVIVOR OF AIDS, LIVING IN SAN FRANCISCO. A FEW YEARS AGO, HE BEGAN SUFFERING AGONIZING PAIN IN HIS FEET DUE TO A CONDITION KNOWN AS NEUROPATHY. Man: THE PAIN WAS VERY, VERY DEEP INSIDE MY FOOT JUST UNDERNEATH THE TOES. THE BEST WAY I CAN DESCRIBE IT AS IF THERE WAS BROKEN GLASS IN THERE, ON THE NERVES TO THE POINT THAT MY LIFE WAS JUST BECOMING VERY SEDENTARY. Alda: AN ACTIVE RUNNER AND VOLUNTEER WITH THE AIDS QUILT PROJECT GEPPETTO APODACA BECAME HOUSEBOUND HIS PAIN CONTROLLABLE ONLY WITH POWERFUL DRUGS. I THOUGHT, IF THIS PAIN CONTINUES AND AS ALL THEY CAN DO FOR ME ARE TRANQUILIZERS THEN I JUST DIDN'T WANT TO GO ON ANY FURTHER. AND THAT'S PRETTY MUCH WHERE I WAS UNTIL I MET THE PAIN-MANAGEMENT CREW AND WENDYE ROBBINS. INTERESTING DAY TO BE DOING THIS FROM A SYMBOLIC PERSPECTIVE. THIS IS THE START OF THE JEWISH CALENDAR. Alda: WENDYE ROBBINS, AN ANESTHESIOLOGIST FIGURED IF HOT PEPPERS NUMB PAIN IN THE MOUTH, WHY NOT ELSEWHERE? Robbins: THAT WAS PART OF THE ORIGINALITY OF THE INVENTION WAS REALIZING THAT THE SAME NERVE FIBERS THAT ARE PRESENT IN THE MOUTH AND SIGNAL HOT OR SPICE WHEN WE EAT THEM ARE ALSO PRESENT ON THE FOOT AND THEREFORE CAN PROBABLY BE INTERACTED WITH IN THE SAME WAY. Alda: GEPPETTO'S TREATMENT BEGINS WITH A POWERFUL LOCAL ANESTHETIC SMEARED ON HIS FEET. Robbins: BEFORE WE PUT CAPSAICIN ON HIM WE HAVE TO MAKE SURE HE'S PRETTY NUMB. OTHERWISE THE CAPSAICIN ITSELF WOULD BE EXQUISITELY PAINFUL. Alda: THE MASK PROTECTS AGAINST THE FUMES FROM THE CAPSAICIN CREAM. Robbins: THIS IS A HUNDREDFOLD MORE POTENT THAN THE STUFF THAT'S AVAILABLE COMMERCIALLY. THIS IS 7½% BY WEIGHT. IF I TOUCHED THIS TO YOUR FOOT OR ANYBODY ELSE'S FOOT THAT WASN'T ANESTHETIZED IT WOULD BE EXCRUCIATINGLY PAINFUL. Alda: WHILE WE WAIT FOR GEPPETTO'S FEET TO BAKE WE HAVE TIME FOR A QUICK VISIT WITH ANOTHER TEAM OF SAN FRANCISCO SCIENTISTS. WITH RESEARCH MATERIALS BOUGHT FROM LOCAL SUPERMARKETS THEIR GOAL WAS TO FIND THE MOLECULE IN OUR BODIES THAT RESPONDS TO PEPPERS' HEAT. AMONG THE PEPPERS DAVID JULIUS AND MICHAEL CATERINA TESTED WAS THE HABANERO, THE HOTTEST OF ALL. IT'S TEARING MY EYES AND MAKING IT A LITTLE HARD TO BREATHE. ALL FOR SCIENCE, YOU KNOW. Alda: WHAT THE RESEARCHERS HAVE FOUND IS THE MOLECULE IN OUR NERVES THAT HOT PEPPERS ACTIVATE WHEN THEY CAUSE THEIR PAINFUL BURN. THE MOLECULE SITS LIKE A TRAPDOOR ON THE SURFACE OF THE PAIN FIBER. CAPSAICIN UNLATCHES THE DOOR, ALLOWING CALCIUM IONS TO RUSH IN AND SO FIRING OFF THE PAIN MESSAGE TO THE BRAIN. HERE'S WHAT HAPPENS WHEN CAPSAICIN IS ADDED TO LIVING CELLS THAT ARE CUED TO LIGHT UP WHEN THE TRAPDOOR OPENS. Man: IF YOU WERE TO TAKE THE NEURONS THAT NORMALLY RESPOND TO PAIN IN OUR BODIES AND SUBJECT THEM TO THIS SAME SORT OF ASSAY THIS IS EXACTLY WHAT THEY WOULD LOOK LIKE. THEY WOULD START OFF PURPLE AND THEN WHEN YOU ADD CAPSAICIN, THEY WOULD ALL LIGHT UP. A SILENT SCREAM. Alda: THE RESEARCHERS DISCOVERED THAT VERY HOT WATER ALSO MAKES CELLS GIVE THIS SAME RESPONSE. IN FACT, THE ORIGINAL JOB OF THE TRAPDOOR MOLECULE IN OUR BODIES MAY HAVE BEEN TO DETECT AND WARN OF DANGEROUS HEAT. SO HERE'S THE ULTIMATE REASON PEPPERS ARE HOT-- CAPSAICIN FOOLS OUR CELLS INTO THINKING THEY'RE ON FIRE. RIGHT NOW GEPPETTO'S FEET KNOW THE FEELING ONLY TOO WELL. I'M BEGINNING TO FEEL A VERY, VERY, VERY HOT SENSATION ON MY FEET RIGHT NOW. Alda: BUT JUST AS THE HOT-PEPPER CANDY RELIEVES MOUTH SORES SO GEPPETTO'S MUCH MORE DRAMATIC TREATMENT SHOULD RELIEVE HIS MUCH MORE DEVASTATING PAIN, ONCE THE BURN WEARS OFF. THE FIRST TIME WE DID IT MY INITIAL FEELING, WHEN I GOT HOME WAS THE PAIN WAS SO BAD FROM THE CAPSAICIN I COULDN'T REALIZE THAT IT WAS GOING TO GET ANY BETTER. AND AS THE THIRD DAY CAME AROUND AND I WAS ABLE TO PUT ON SHOES COMFORTABLY FOR THE FIRST TIME IT WAS LIKE BEING BORN AGAIN. Alda: THIS TIME GEPPETTO WAS RUNNING AGAIN WITHIN THE WEEK AND IF HIS PREVIOUS TREATMENTS ARE A GUIDE HE'LL REMAIN VIRTUALLY PAIN-FREE FOR MONTHS. MEANWHILE, WENDYE ROBBINS HOPES THAT MANY OTHER PATIENTS WITH DEBILITATING PAIN CAN ALSO BE TREATED WITH PEPPERS' CHEMICAL HEAT. YOU SEE WHAT I MEAN? ONE THING IN SCIENCE JUST SEEMS TO KEEP LEADING TO ANOTHER. ONE THING WE DO A LOT ON THIS SHOW IS FLY ACROSS TIME ZONES.

				Sand to Nuts Why do coffee spills form rings? Why do brazil nuts always rise to the top of a can of mixed nuts? Physicists find big answers to these little questions.
		Select text to jump ahead in the clip: THE BEACH IS A GREAT PLACE FOR THINKING UP TRIVIAL QUESTIONS. FOR INSTANCE, HAVE YOU EVER NOTICED THAT WHEN YOU WALK IN WET SAND THE COLOR OF THE SAND CHANGES IN A SORT OF HALO AROUND EACH FOOTSTEP? WHY IS THAT? IT'S NO COINCIDENCE THAT THIS PARTICULAR LITTLE QUESTION POPPED UP HERE ON THE SHORE OF LAKE MICHIGAN IN CHICAGO BECAUSE AT THE UNIVERSITY OF CHICAGO ARE A COUPLE OF SCIENTISTS WHO JUST LOVE ASKING TRIVIAL QUESTIONS ABOUT STUFF LIKE... WELL, LIKE SAND. YOU REALLY DO LOVE SAND, HUH? OF COURSE-- IT'S ONE OF THE BEST SUBSTANCES THERE IS. WHAT ABOUT MY QUESTION? WHY DO WE GET THIS SORT OF WHITE HALO AROUND OUR FOOTSTEPS WHEN WE WALK IN WET SAND? WHAT WE'VE GOT HERE IS SOME SAND IN THIS SQUEEZE BOTTLE. AND WE'VE FILLED IT WITH WATER TO A LITTLE BIT HIGHER THAN THE LEVEL OF SAND. AND SO, AS I SQUEEZE THIS, WHAT'S GOING TO HAPPEN? NORMALLY YOU WOULD THINK THAT EVERYTHING IS JUST GOING TO RISE. BUT AS YOU SAW WITH THE SAND NEAR THE LAKE YOU SQUEEZE IT AND THE WATER DROPS BELOW THE LEVEL OF THE SAND. ( laughing ): THAT'S GREAT. YOU LET GO OF IT AND THE SAND GOES DOWN AND YOU HAVE A LAYER OF WATER ON TOP. YOU SQUEEZE IT... LOOK AT ALL THAT WATER. IT SEEMS TO GO ALL THE WAY DOWN THERE AND THE SAND MOVES RIGHT UP. Alda: THE EXPLANATION'S ACTUALLY SIMPLE. SQUEEZING THE BOTTLE MAKES THE SAND GRAINS MOVE PAST EACH OTHER AND TO DO THAT, THEY MUST FIRST MOVE SLIGHTLY APART. THE WATER THEN RUNS DOWN INTO THE BIGGER SPACES BETWEEN THEM. ON THE BEACH, MY WEIGHT PUSHED THE SAND GRAINS APART AND THE WATER DRAINING AWAY CREATED THE HALOES. IN FACT, WHENEVER GRAINS MOVE THEY MUST FIRST MOVE AWAY FROM EACH OTHER. FOR INSTANCE, ONLY THE SEEDS ON THE SURFACE OF THIS AVALANCHE HAVE THE ROOM TO EXPAND, AND SO TO FLOW. AND IT'S WHEN SAND FLOWS THAT IT GETS REALLY INTERESTING. WHAT IS THIS ORANGE THING? OKAY, THIS IS A PUZZLE WHICH IS... IT'S GOT ORANGE SAND IN THIS PLASTIC TUBE AND IN THE MIDDLE OF THE SAND, WE HAVE THIS BIG STEEL BALL. AND THE QUESTION THAT I HAVE FOR YOU IS THE BALL IS AT ONE SIDE AND I WANT YOU TO GET THE BALL OVER TO THE OTHER SIDE OF THE CONTAINER. OKAY, SO THE BALL'S ON THIS SIDE. I HAVE TO GET THE BALL TO THIS SIDE OF THE SAND, HUH? THAT'S THE IDEA. OKAY, SO THE FIRST THING, OBVIOUSLY IS TO TRY TO SHAKE IT. Alda: WELL, MAYBE OBVIOUS BUT EQUALLY OBVIOUSLY NOT EFFECTIVE. STUBBORNLY, THE BALL REFUSES TO SINK. SUPPOSE YOU TURN IT UPSIDE DOWN? UH, SO... WOW, LOOK AT THAT! IT'S CLIMBING RIGHT UP! Man: THEN YOU EASE IT OFF. THERE IT IS, THERE IT IS. RIGHT AT THE TOP. OKAY, WHAT MAKES IT CLIMB UP THROUGH THE SAND LIKE THAT? GREAT QUESTION. AND TO ANSWER THAT, WE'RE GOING TO THE LAB. Alda: THE LAB WE'RE HEADING FOR IS THE UNIVERSITY OF CHICAGO'S MATERIALS CENTER. SO THIS IS THE TWO-DIMENSIONAL VERSION IN A REAL LABORATORY SITUATION OF WHAT YOU SAW HERE. Jaeger: LET'S JUST TURN THIS THING ON. ( machine humming ) Alda: LOOK AT THAT-- WOW! AND... OH, AND THERE IT GOES! DOWN THE SIDE. I WAS JUST GOING TO SAY THAT I CAN SEE POPPY SEEDS MOVING DOWN HERE. Nagel: BUT THAT BIG ONE CAN'T MAKE IT, CAN IT? Alda: NO. Alda: THE ONLY THING GOING ON HERE IS THAT THE CONTAINER IS BEING BRISKLY SHAKEN UP AND DOWN. IT'S A FANCY VERSION OF WHAT CAN SOMETIMES HAPPEN IF YOU SHAKE A CAN OF MIXED NUTS. THE SHAKING UNMIXES THEM CAUSING THE LARGE NUTS TO RISE TO THE TOP. REMARKABLY, THERE'S NEVER BEEN A GOOD EXPLANATION FOR THIS PHENOMENON. BUT A CLUE CAME FROM THAT THIN, DOWNWARD STREAM OF GRAINS I'D NOTICED ALONG THE WALL. HERE'S WHAT SID AND HEINRICH THINK IS HAPPENING. AS THE GRAINS ARE THROWN UPWARD THOSE NEAREST THE WALL ARE DRAGGED AGAINST IT SLOWING THEM DOWN. WHEN THE GRAINS FALL, THEY'RE LESS DENSELY PACKED SO THERE'S LESS DRAG AGAINST THE WALLS. THE RESULT: THE GRAINS NEXT TO THE WALL SLOWLY MOVE DOWNWARD SETTING UP A SORT OF CONVECTION CURRENT. THE CURRENT RISES IN THE CENTER, CARRYING EVERYTHING WITH IT. BUT AT THE WALLS, THE CURRENT IS TOO NARROW TO TAKE LARGE OBJECTS DOWN AGAIN SO THEY'RE LEFT STRANDED AT THE TOP. IN A SHAKEN CAN OF MIXED NUTS THE BRAZIL NUTS PRESENT THEMSELVES READY FOR EATING. ALL VERY INTERESTING, BUT... Alda: SUPPOSE MIXED NUTS IS NOT THE MOST IMPORTANT THING IN YOUR LIFE. WHAT ELSE DOES THIS APPLY TO-- ANYTHING? OR IS IT JUST GREAT THAT WE HAVE THIS UNDERSTANDING OF HOW PARTICLES MOVE? MIXING IS A TERRIBLY IMPORTANT THING, LET'S SAY IN THE PHARMACEUTICAL INDUSTRY. THAT IS, IF YOU ARE MAKING PILLS OUT OF VARIOUS POWDERS, YOU WANT TO MIX THEM. AND IF YOU DON'T MIX THEM PROPERLY THEN YOU'LL HAVE SOME PILLS THAT HAVE ALL THE BINDER AND OTHER PILLS THAT HAVE ALL THE GOOD STUFF BUT HAVING ALL THE GOOD STUFF IN ONE PILL IS VERY, VERY BAD. YOU COULD KILL SOMEBODY. YOU COULD KILL SOMEBODY WITH THAT. Alda: A GREAT EXAMPLE OF HOW AN APPARENTLY TRIVIAL QUESTION CAN LEAD TO A VERY NONTRIVIAL ANSWER. AND HOW ABOUT THIS ONE? WHY DOES AN HOURGLASS INVARIABLY CONTAIN SAND? Alan: WOULD ANYTHING WORK IN AN HOURGLASS? COULD I PUT WATER IN AN HOURGLASS AND WOULD I GET THE SAME TIME-KEEPING ABILITY? Jaeger: YOU COULD PUT WATER IN AN HOURGLASS, OF COURSE. BUT IT WOULDN'T DO ME ANY GOOD. IT WOULDN'T DO YOU ANY GOOD. IT WOULD NOT DO THE FOLLOWING. IT WOULD NOT BE A LINEAR KEEPER OF TIME. IN OTHER WORDS, WHAT MAKES THE SAND HERE SO REMARKABLE IS THAT NO MATTER HOW HIGH THE FILLING HEIGHT IS HERE THE FLOW RATE AT THE ORIFICE IS ALWAYS THE SAME. SO IF YOU HAD MARKINGS THAT TELL YOU TIME-- ONE MINUTE, TWO MINUTES-- THEY ARE EQUALLY SPACED. IT HAS TO DO WITH THE FACT THAT... MOST OF THE WEIGHT UP HERE IS UNLOADED NOT STRAIGHT ONTO THE HOLE BUT IT IS GOING TOWARDS THE SIDE WALLS. Alda: THE WEIGHT GOES TO THE SIDES? HARD TO BELIEVE... UNTIL HEINRICH AND SID GOT MY COMPETITIVE JUICES FLOWING WITH A SIMPLE CHILDREN'S GAME. YOU REALLY GOT MY INTEREST NOW. Alda: THE CURVED BAR, WHICH IS LIKE GRAVITY PUSHES DOWN ON THE WOODEN DISCS, REPRESENTING GRAINS. I SEE A SPACE HERE. MM-HMM. Alda: THE TRICK IS TO REMOVE THE DISCS THAT AREN'T HOLDING UP THE BAR. THIS LOOKS LIKE IT'S FREE. YEAH, ALL RIGHT. WELL, I GOT A... IT'S A BIG ONE. YEAH, SO YOU'RE... THIS LOOKS LIKE IT'S VERY MUCH CONNECTED BUT THIS DOESN'T LOOK LIKE IT'S CONNECTED. THERE, I GOT ANOTHER ONE. BEAUTIFUL. I'M PRETTY GOOD. NOW, THIS ONE I GET FOR FREE. BUT IT COULD BE ALL THE WAY DOWN HERE. MM-HMM. MM-HMM. I'M GUESSING THIS DOESN'T CONNECT TO ANYTHING... YEAH. Jaeger: BEAUTIFUL. BUT THIS MUST. THAT'S RIGHT. NOW, THAT WAS REALLY A FORCE AGAINST THE SIDE, WASN'T IT? CORRECT. AND SO WE STARTED WITH A FORCE COMING DOWN THIS WAY BUT WE ENDED UP WITH A FORCE AGAINST THE WALLS. THE MATERIAL DIVERTED THE FORCE AGAINST THE WALL AND THAT IS WHY THE HOURGLASS HAS THIS CONSTANT FLOW RATE, BECAUSE MUCH OF THE FORCES FROM ALL THE MATERIAL ABOVE THE ORIFICE GETS DIVERTED AGAINST THE WALLS. SO MILD, YOU KNOW, SO... Alda: ONE OF SID NAGEL'S FAVORITE TRIVIAL QUESTIONS CONFRONTED HIM ONE DAY FROM HIS KITCHEN COUNTER. ARE THESE HISTORIC COFFEE STAINS HERE? ARE THESE THE ONES THAT GAVE YOU YOUR INSPIRATION? NO, THEY'RE A DAY OLD OR SO. BUT WHEN THEY'RE LOVELY AS THIS WOULDN'T YOU HAVE TROUBLE WIPING THEM UP? Alda: YES, IT'S TRUE-- SID REALLY DOES FIND COFFEE STAINS BEAUTIFUL BECAUSE THEY MADE HIM WONDER WHY, WHEN A COFFEE SPILL DRIES IT ALWAYS LEAVES A RING. Nagel: SO, THIS IS WHERE WE... Alda: ENOUGH OF SID'S COLLEAGUES TOOK THE QUESTION SERIOUSLY THAT EXPERIMENTS BEGAN TO WATCH WHAT HAPPENS AS A COFFEE SPILL DRIES. SO ROB HERE HAS BEEN... HI. NICE TO MEET YOU. LOOKING UNDER A MICROSCOPE AT SOME OF THE DROPS WHERE INSTEAD OF USING COFFEE WE'VE USED PARTICLES THAT YOU CAN ACTUALLY VISUALIZE UNDER MICROSCOPES. Alda: I'M SEEING A LOT OF PARTICLES MOVING FROM OVER HERE TO THE EDGE. Alda: THE QUESTION WAS, WHAT'S CAUSING THIS FLOW? THE ANSWER HINGED ON THE FACT THAT THE EDGE OF A SPILL BECOMES PINNED IN PLACE BY TINY ROUGH SPOTS ON THE SURFACE SO THE EDGE CAN'T PULL BACK AS THE LIQUID EVAPORATES. AS THE EDGE LOSES LIQUID TO THE AIR IT HAS TO BE REPLENISHED BY LIQUID FROM WITHIN THE DROP AND THE FLOW THAT RESULTS CARRIES WITH IT THE TINY SUSPENDED PARTICLES. IS THIS WHITE BAND... PARTICLES THAT HAVE BUILT UP ON THE EDGE ALREADY? Nagel: YES, THAT'S RIGHT. AND SO YOU SEE HOW SLOWLY AND CAREFULLY THEY COME IN THERE AND THEY PACK VERY NICELY INTO A VERY WELL PACKED, ALMOST CRYSTALLINE RING. Alda: THE CAREFUL PACKING MEANS THAT EVEN THIS HUMBLE DISCOVERY COULD HAVE UNEXPECTEDLY USEFUL CONSEQUENCES-- FOR INSTANCE, IN MANUFACTURING ULTRAFINE WIRES IN ELECTRONIC CIRCUITS. SO EVEN IN COFFEE STAINS, THERE CAN BE INSPIRATION. Alda: IT'S REALLY INTERESTING THAT THIS KIND OF A STAIN FROM A FEW DROPS OF COFFEE HAS PROBABLY SHOWN UP ON COUNTLESS MILLIONS, THOUSANDS OF MILLIONS, OF COUNTER TOPS... Nagel: ON MY COUNTER TOP ALONE IT'S SHOWN UP THAT MANY TIMES! ( laughing ) AND MANY OF THOSE COUNTER TOPS WERE THE COUNTER TOPS OF SERIOUS, CURIOUS SCIENTISTS. AND YET YOU AND THE PEOPLE YOU WORK WITH TOOK THESE STAINS SERIOUSLY AND YOU THOUGHT SOMETHING CAN BE LEARNED FROM THAT THAT WILL LEAD US TO A DEEPER UNDERSTANDING OF THINGS OTHER THAN COFFEE STAINS. I HAVE THIS KIND OF BROAD VIEW OF WHAT PHYSICS SHOULD BE. AND IT'S NOT JUST BUILDING THE GREAT, BIG, NEW SUPERCONDUCTING SUPERCOLLIDER OR A GREAT NEW "BIG BANG" THEORY OF THE UNIVERSE. BUT IT'S ALSO TRYING TO UNDERSTAND PHENOMENA SUCH AS THIS THAT REALLY GIVES US THE TEXTURE AND THE FEEL OF OUR DAILY LIVES AND IT'S JUST IMPORTANT TO UNDERSTAND. IT SEEMS POSSIBLE, THEN THAT BY STUDYING THINGS LIKE COFFEE STAINS ON THE COUNTER TOP AND SAND IN AN HOURGLASS OR NUTS IN A CONTAINER OF MIXED NUTS REALLY CAN GIVE YOU SOME INSIGHT INTO THE WAY THE WHOLE UNIVERSE IS FORMED. Alda: WHICH, IF YOU'LL RECALL, IS JUST WHERE WE CAME IN. 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