http://indianapublicmedia.org/amomentofscience You have questions and A Moment of Science has answers. Short science videos and audio science podcasts provide the scientific story behind some of life\'s most perplexing mysteries. There\'s no need to be blinded by science. Explore it, have fun with it, but most of all learn from it. A Moment of Science is a production of WFIU Public Media from Indiana University in Bloomington, Indiana. Fri, 19 Mar 2010 13:00:33 +0000 http://wordpress.org/?v=2.9.1 en hourly 1 1998-2009 aschweig@indiana.edu (A Moment of Science (amomentofscience.org)) aschweig@indiana.edu (A Moment of Science (amomentofscience.org)) Science and Technology 1440 science, technology, chemistry, biology, physics, health, podcast, wfiu A Moment of Science is a production of WFIU Public Media from Indiana University. You have questions and A Moment of Science has answers. These two-minute audio podcasts provide the scientific story behind some of life\'s most perplexing mysteries. There\'s no need to be blinded by science. Explore it, have fun with it, but most of all learn from it. A Moment of Science is a production of WFIU Public Media from Indiana University in Bloomington, Indiana. A Moment of Science (amomentofscience.org) A Moment of Science (amomentofscience.org) aschweig@indiana.edu No no http://wfiu.org/images/podcast_logos/amos_podcast.jpg http://indianapublicmedia.org/amomentofscience 144 144 http://indianapublicmedia.org/amomentofscience/centripetal-force-and-merry-go-rounds/ http://indianapublicmedia.org/amomentofscience/centripetal-force-and-merry-go-rounds/#comments Fri, 19 Mar 2010 13:00:33 +0000 A Moment of Science http://indianapublicmedia.org/amomentofscience/?p=14699 http://indianapublicmedia.org/amomentofscience/centripetal-force-and-merry-go-rounds/feed/ 0 2:02 The next time you're at a park, watch children playing on a merry-go-round and you'll notice that kids sitting in the center of the merry-go-round ... The next time you're at a park, watch children playing on a merry-go-round and you'll notice that kids sitting in the center of the merry-go-round don't get as dizzy as those hanging on the edge. That's because the inner ear helps you keep your balance, and when your inner ear is disturbed by a force such as spinning, you feel dizzy. Kids on the edge of the merry-go-round are experiencing greater force, and therefore are getting dizzier, than those at the center. Here's why. Dizzy, Dizzy, Dizzy Physics tells us that objects at rest want to stay at rest, and those in motion want to stay in motion, and when these objects are in motion, they naturally move in a straight line. To get an object to move in anything other than a straight line, you have to exert force on it. A force is required for an object to move in a circle, as is the case with a merry-go-round. This force is called a centripetal force. Centripetal Force Generally speaking, the larger the circle you move in, the greater the centripetal force you experience. So, the farther you move away from the center of the merry-go-round, the more force the merry-go-round must exert on you to keep you moving in that circle. All this extra force on your inner ear can make you lose your balance and feel quite dizzy. Try An Experiment Another way to see centripetal force in action is with an old-fashioned record player. Place a penny near the center of a spinning record, and it will stay in place as it turns. Put the penny on the edge, however, and it will fly off the record, giving visible proof that the force at the edge of a spinning object is greater than at the center. Content,Type,,Podcasts,,shows A Moment of Science (amomentofscience.org) no No http://indianapublicmedia.org/amomentofscience/vaccines-keep-people-healthy-and-safe/ http://indianapublicmedia.org/amomentofscience/vaccines-keep-people-healthy-and-safe/#comments Thu, 18 Mar 2010 13:00:02 +0000 A Moment of Science http://indianapublicmedia.org/amomentofscience/?p=14694 http://indianapublicmedia.org/amomentofscience/vaccines-keep-people-healthy-and-safe/feed/ 0 2:03 When a virus enters your body, your body has to recognize it, then produce a protein called an antibody. These antibodies attach to the ... When a virus enters your body, your body has to recognize it, then produce a protein called an antibody. These antibodies attach to the virus and neutralize it; however, in the time it takes your body to produce enough antibodies, the virus may have already multiplied enough to make you sick. How Do Vaccines Work? Here's the good news once your body has learned to make the right antibodies, it can make them much faster, neutralizing the virus before you get sick. Vaccines teach your body to recognize and react to a virus quickly. Inactive Vaccines There are two types of vaccines you can get to teach your body to recognize a virus. Inactivated vaccines contain a dead virus, which cannot infect your cells, but your body recognizes it as a virus and produces antibodies to neutralize it. The vaccines for polio and the seasonal flu use dead viruses. Attenuated Virus The second type of vaccine contains an attenuated virus. This virus is alive, but has been grown in the lab for several generations, so it isn't able to multiply very well in humans. With the attenuated virus multiplying very slowly, your body is able to produce the correct antibodies before you get sick. Measles and mumps vaccines are both made with attenuated viruses. So, How Does All This Work? When most people in a community have become resistant to the virus, either through a vaccination or by having the virus and recovering, the community develops what is called "herd immunity". The nice thing about herd immunity is that it becomes statistically less likely for the germ to find a person without immunity. This protects members of the community who haven't been vaccinated, or had the disease, by reducing their chances of encountering an infected person. Content,Type,,Podcasts,,shows A Moment of Science (amomentofscience.org) no No http://indianapublicmedia.org/amomentofscience/grass-into-ethnaol-fuel/ http://indianapublicmedia.org/amomentofscience/grass-into-ethnaol-fuel/#comments Wed, 17 Mar 2010 13:00:05 +0000 A Moment of Science http://indianapublicmedia.org/amomentofscience/?p=14690 http://indianapublicmedia.org/amomentofscience/grass-into-ethnaol-fuel/feed/ 0 2:03 You may have heard about the potential for turning grasses into ethanol fuel. Is this happening? So first, it's true that there's a lot of interest ... You may have heard about the potential for turning grasses into ethanol fuel. Is this happening? So first, it's true that there's a lot of interest in cellulosic ethanol--that is, fuel made from plants not used for food. And it's also true that scientists have been experimenting with different grasses as potential fuel crops. Miscanthus But we're not talking about the kind of grass in your average lawn. Scientists are mainly interested in tall grasses that grow quickly--like Miscanthus gianteus. It's a large perennial grass native to Japan that grows to about thirteen feet. Why not corn? What's interesting about Miscanthus is that you can grow a lot of it on a relatively small parcel of land. For example, a typical acre of corn produces around 750 gallons of ethanol. But an acre of Miscanthus produces more than 3200 gallons. So why aren't we using Miscanthus to make biofuel right now? Scientists still don't know enough about the best way to grow and harvest Miscanthus, or the most efficient way to process it into biofuel. Some European countries burn Miscanthus alongside coal in power plants. But the bigger goal is to use Miscanthus to make liquid fuel. Right now, though, the process is too expensive. The future But one day, Miscanthus could be an important energy crop.nbsp; Given all the scientific attention being paid to Miscanthus, it may not be long before we're filling our tanks with gas made from grass. Read More: Miscanthus (bioenergy) Content,Type,,Podcasts,,shows A Moment of Science (amomentofscience.org) no No http://indianapublicmedia.org/amomentofscience/earthquake-ultrasounds-how-scientists-are-measuring-seismic-waves/ http://indianapublicmedia.org/amomentofscience/earthquake-ultrasounds-how-scientists-are-measuring-seismic-waves/#comments Tue, 16 Mar 2010 13:00:43 +0000 A Moment of Science http://indianapublicmedia.org/amomentofscience/?p=14626 http://indianapublicmedia.org/amomentofscience/earthquake-ultrasounds-how-scientists-are-measuring-seismic-waves/feed/ 0 2:03 Did you know geologists can look at rocks deep beneath the surface using sound, just like a doctor uses an ultrasound machine to see a ... Did you know geologists can look at rocks deep beneath the surface using sound, just like a doctor uses an ultrasound machine to see a developing baby? Ultrasounds Ultrasounds and seismic waves are both types of sound waves, and they need a medium like air, liquid or rock to travel through. Because of that, when they come to a boundary between two substances, some of the sound gets reflected. Two Types Of Seismic Waves With medical ultrasound, the waves reflect off the surface of the baby's body. There are two types of seismic waves. P-waves travel through liquids and solids, and S-waves only travel through solids. When they hit boundaries between different substances they change directions, showing the earth's structure. The earth is its own ultrasound machine. All scientists have to do is record when and where the waves occur. New Discoveries Scientists measuring layers of rock in an area of the Pacific floor called the Nankai Trough discovered why earthquakes trigger tsunamis from that area. A major fault runs from six miles deep right up to the sea floor. When an earthquake happens there, the fault lets the sea floor move up and down, creating large waves. Other scientists in the San Francisco Bay area have mapped the area to determine where faults are located and where earthquakes will occur. Content,Type,,Podcasts,,shows A Moment of Science (amomentofscience.org) no No http://indianapublicmedia.org/amomentofscience/saccade/ http://indianapublicmedia.org/amomentofscience/saccade/#comments Mon, 15 Mar 2010 13:00:12 +0000 A Moment of Science http://indianapublicmedia.org/amomentofscience/?p=14622 http://indianapublicmedia.org/amomentofscience/saccade/feed/ 0 2:03 Have you ever noticed that you can't see your eyes move when you look in a mirror? Put your face close to the bathroom mirror and ... Have you ever noticed that you can't see your eyes move when you look in a mirror? Put your face close to the bathroom mirror and look yourself in the eye. Notice the appearance of your eyes. Now, without blinking, look down at your nose, but continue to notice your eyes. Your eyes look different. They've moved, but the movement itself was invisible to you. An Interesting Movement If you have someone else do the same thing while you watch, you'll easily see the other person's eyes move. To make the comparison as fair as possible, you should put your face right next to the other person's and look at the other person's nose in the mirror. You've just witnessed a mysterious process that shuts off our vision, at least partly, whenever our eyeballs move rapidly. Saccade The kind of quick eye motion we're talking about is called a saccade, from a French word meaning to twitch or jerk. During the fraction of a second that a saccade takes, images sweep over our retinas at high speed. Yet we don't get a feeling of motion, because our brain suppresses visual perception during saccades. Otherwise, the world might look to us like a bad home video where the photographer held the "record" button down while swinging the camera around the room. An odd thing about this suppression is that it's not complete. Get in the car and have someone drive you past a roadside fence. Without moving your head, glance quickly from front to back; you can make the fenceposts seem to freeze for an instant. Why, in this case, is vision not suppressed? A team of visual scientists published a study of this question in the journal Nature. They found that what gets suppressed during a saccade are large areas of light and dark. Those are the perceptions that seem to contribute the most to a sense of motion. Finer details, like fenceposts, are not suppressed, maybe because there's no need to suppress them rapid eye motions usually turn them into a blur anyway. Content,Type,,Podcasts,,shows A Moment of Science (amomentofscience.org) no No http://indianapublicmedia.org/amomentofscience/tinnitus-annoying-ringing-buzzing-ear/ http://indianapublicmedia.org/amomentofscience/tinnitus-annoying-ringing-buzzing-ear/#comments Fri, 12 Mar 2010 13:00:17 +0000 A Moment of Science http://indianapublicmedia.org/amomentofscience/?p=14613 http://indianapublicmedia.org/amomentofscience/tinnitus-annoying-ringing-buzzing-ear/feed/ 0 2:03 It's not uncommon, now and again, to hear a ringing or buzzing in the ear. The condition is called tinnitus, and it can be caused ... It's not uncommon, now and again, to hear a ringing or buzzing in the ear. The condition is called tinnitus, and it can be caused by a number of things such as ear infections, allergies and even as a medication side effect. Tinnitus For most people, tinnitus is temporary. But for some, it's a chronic, debilitating condition. Tinnitus caused by noise induced hearing loss is particularly difficult. When hearing is damaged, the brain sometimes compensates by creating its own noise, so to speak. But the problem is that the noise can take the form of a high decibel whistle, or static. A Health Concern? At its worst, chronic tinnitus can make relaxing and sleeping nearly impossible, which can lead to a range of stress related health problems. Now, there's no cure for tinnitus, but there are some good treatments. In fact, in recent years audiologists have come up with some ingenious therapies. One of these involves using music to trick the brain into muting or at least lowering the volume on tinnitus. Here's How It Works... Basically, the audiologist embeds musical tracks with a frequency specially designed to mask and cancel out the patient's tinnitus. The patient then listens to the music for a few hours every day. And over several months, the frequency in the music causes the brain's audio cells to rewire themselves in a way that makes the tinnitus less audible. So the ringing is technically still there, but over time it fades. Read More: Tinnitus (MedicineNet) Content,Type,,Podcasts,,shows A Moment of Science (amomentofscience.org) no No http://indianapublicmedia.org/amomentofscience/is-it-possible-to-be-too-clean/ http://indianapublicmedia.org/amomentofscience/is-it-possible-to-be-too-clean/#comments Thu, 11 Mar 2010 13:00:13 +0000 A Moment of Science http://indianapublicmedia.org/amomentofscience/?p=14021 http://indianapublicmedia.org/amomentofscience/is-it-possible-to-be-too-clean/feed/ 0 2:02 Being clean is a good thing. After all, simply washing your hands regularly can help ward off flu and other contagious diseases. Is It Possible To Be ... Being clean is a good thing. After all, simply washing your hands regularly can help ward off flu and other contagious diseases. Is It Possible To Be Too Clean? Maybe... For the past few decades scientists have been debating the so called "hygiene hypothesis"--the idea that being exposed to a wide range of microbes early on helps strengthen the immune system. According to the hypothesis, too much anti microbial cleanliness at a young age can throw the immune system out of whack, causing it to overreact later on. Good Bacteria Now, a study lends support to this idea. Scientists have found that bacteria living on our skin help prevent cuts from becoming inflamed when the immune system reacts to the wound. The immune system is only trying to help, of course. When we get cut a cut or wound, immune cells rush to the area to fend off foreign particles that might cause infection. And some inflammation is inevitable. But too much inflammation is bad--it can cause diseases like rheumatoid arthritis. Immune System And Hygiene Hypothesis So according to the study, skin bacteria dampen the immune cells' activity enough to prevent excessive inflammation without hampering the immune system's ability to fight infection. This doesn't prove the hygiene hypothesis, exactly. But it does show that bacteria on, and maybe in, our bodies help the immune system do its job without going out of control. Read More: Dirt Can Be Good For Children, Say Scientists (news.bbc.co.uk) Podcasts,,shows A Moment of Science (amomentofscience.org) no No http://indianapublicmedia.org/amomentofscience/med_students_needles/ http://indianapublicmedia.org/amomentofscience/med_students_needles/#comments Wed, 10 Mar 2010 13:00:20 +0000 A Moment of Science http://indianapublicmedia.org/amomentofscience/?p=14017 http://indianapublicmedia.org/amomentofscience/med_students_needles/feed/ 0 2:02 Medical school is a bear. Med students have to endure long hours, little sleep, and tons of pressure. And, getting stuck by needles. Getting Stuck According to one ... Medical school is a bear. Med students have to endure long hours, little sleep, and tons of pressure. And, getting stuck by needles. Getting Stuck According to one study, med students on track to become surgeons get stuck often. Of the nearly 700 med school graduates studied, more than eighty percent reported having been stuck by a needle at some point during their training. And nearly half didn't bother to report the injury, or didn't feel the need. Are Needles A Big Deal? Well, so what? Doctors in training handle a lot of needles, whether for giving shots or sewing up surgical wounds. So maybe an occasional needle stick simply comes with the territory. A Dangerous Problem Maybe, but it can also be dangerous. Getting stuck with a needle used on a patient with HIV or some other contagious disease is obviously a problem. And the fact that so many medical students are apparently getting stuck on a regular basis could mean that medical schools aren't doing enough to train students how to properly handle needles. Why Is It Not Reported? As for why most students don't report needle stick injuries--that may have to do with the macho culture of medical training. Reporting mistakes--especially small, self inflicted ones--is not encouraged. Plus, many med students simply don't have the time to go through the often lengthy process of reporting an injury. But reporting needle stick injuries should be encouraged, according to the study. Because the more hospitals and medical schools know about how and why students are getting stuck by needles, the better able they'll be to address the problem. After all, most people don't like getting stuck with needles. And doctors are no exception. Read More: Medical Student Needlestick Injuries (KevinMD.com) Content,Type,,Podcasts,,shows A Moment of Science (amomentofscience.org) no No http://indianapublicmedia.org/amomentofscience/attract-and-repel-how-fruit-uses-ripeness-to-germinate/ http://indianapublicmedia.org/amomentofscience/attract-and-repel-how-fruit-uses-ripeness-to-germinate/#comments Tue, 09 Mar 2010 13:00:50 +0000 A Moment of Science http://indianapublicmedia.org/amomentofscience/?p=13992 http://indianapublicmedia.org/amomentofscience/attract-and-repel-how-fruit-uses-ripeness-to-germinate/feed/ 0 2:03 Usually a green, sour fruit is just a fruit that's not ripe yet. If you left a lime on the tree longer would it ... Usually a green, sour fruit is just a fruit that's not ripe yet. If you left a lime on the tree longer would it eventually change color and become sweet, like an orange? Color changes Actually, limes do become much more yellow and less sour as they ripen. Under ripe limes are darker green and quite bitter. There are other clues to their ripeness too. Ripe limes are heavy with juice and more aromatic, with a fragrant "limey" smell. Most fruits we eat use similar cues to advertise ripeness. Why would plants want parts of them to be eaten? Fruiting plants have evolved a partnership with certain animals in order to increase the success of their seeds. Tasty fruit pulp is the reward plants offer to animals in exchange for dispersing their seeds. Frugivores Plants attract fruit eaters--or "frugivores"--by packing valuable resources into their fruits like sugar and water or important nutrients such as carotenoids, vitamins and minerals. Plants often target specific animals that will give their seeds the best chances for germination, and discourage or repel animals that won't. Attract and repel Plants that want to attract birds rather than mammals might produce thorns or have fruits that taste unpalatable to most mammals but tasty to birds. Plants that want to repel birds but attract mammals might have fruits with thicker, tougher outer skins. Don't forget that selective breeding by humans has dramatically changed many fruits from their wild state, often resulting in larger, sweeter fruits with fewer seeds. Read More: Plant-Animal Interactions: An Evolutionary Approach (Amazon) Podcasts,,shows A Moment of Science (amomentofscience.org) no No http://indianapublicmedia.org/amomentofscience/speech-errors-brain-damage-tongue-twisters-and-children/ http://indianapublicmedia.org/amomentofscience/speech-errors-brain-damage-tongue-twisters-and-children/#comments Mon, 08 Mar 2010 13:00:18 +0000 A Moment of Science http://indianapublicmedia.org/amomentofscience/?p=13985 http://indianapublicmedia.org/amomentofscience/speech-errors-brain-damage-tongue-twisters-and-children/feed/ 0 2:03 What do brain damaged patients, adults saying tongue twisters and all children have in common? They're more likely to make speech errors than an ... What do brain damaged patients, adults saying tongue twisters and all children have in common? They're more likely to make speech errors than an adult who is speaking under normal circumstances. "Silly Sog!" A common type of speech error in children occurs when one sound persists and interferes with the rest of their phrase. For example, if a child wanted to say the "silly dog," it might come out the "silly sog." Young speakers often get stuck on a single sound when what they have just said intrudes on what they're currently saying. "Dilly Dog!" Adult speakers, on the other hand, make far fewer errors and the ones they do make tend to be anticipatory; for these speakers, what they are about to say intrudes on what they're currently saying. When adults make this kind of speech error, they would say "dilly dog" instead of "silly dog." Suppress What We've Said The difference between these two mistakes may seem unimportant to a lay person, but to a cognitive psychologist it is crucial for understanding how language development occurs. In order for us to construct meaningful language, we must learn how to suppress things we've already said. In addition, we must learn how to activate in memory what we are currently trying to say and what we are about to say. Brain Damage Children haven't learned how to suppress in memory what they've just said or how to activate in memory what they're currently saying. A brain-damaged patient may make similar errors if the part of his or her brain responsible for this kind of memory suppression and activation has been harmed. And an adult repeating a tongue twister might make this kind of error because the brain is processing so much unusual information that it temporarily loses its ability to perform these activating and suppressing activities. 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