http://www.odeo.com/channels/2109690-Experiment-of-the-Week no A lifelong fascination with science, combined with an uncontrollable urge to teach has led me on adventures ranging from excavating dinosaur bones in Wyoming to watching whales off the coast of Mexico. <p> During my thirteen years at the Memphis Museum, I wrote and taught classes in geology, biology, chemistry, archaeology and physics. In 1987, I decided it was time for a change and put together a traveling, high voltage electricity show, centered on a one million volt Tesla coil. </p><p> I am picking out some of my favorite science experiments from the early years of my mailing list (1997-2001), and posting them here as videos. I am revising the text versions too, so you can watch the video and print the new text version for your files from my website, www.krampf.com.</p> A lifelong fascination with science, combined with an uncontrollable urge to teach has led me on adventures ranging from excavating dinosaur bones in Wyoming to watching whales off the coast of Mexico. During my thirteen years at the Memphis Museum, I wrote and taught classes in geology, biology, chemistry, archaeology and physics. In 1987, I decided it was time for a change and put together a traveling, high voltage electricity show, centered on a one million volt Tesla coil. I am picking out some of my favorite science experiments from the early years of my mailing list (1997-2001), and posting them here as videos. I am revising the text versions too, so you can watch the video and print the new text version for your files from my website, www.krampf.com. A lifelong fascination with science, combined with an uncontrollable urge to teach has led me on adventures ranging from excavating dinosaur bones in Wyoming to watching whales off the coast of Mexico. During my thirteen years at the Memphis Museum, I wrote and taught classes in geology, biology, chemistry, archaeology and physics. In 1987, I decided it was time for a change and put together a traveling, high voltage electricity show, centered on a one million volt Tesla coil. I am picking out some of my favorite science experiments from the early years of my mailing list (1997-2001), and posting them here as videos. I am revising the text versions too, so you can watch the video and print the new text version for your files from my website, www.krampf.com. en 40 Mon, 04 May 2009 10:30:57 -0700 Mon, 04 May 2009 10:30:57 -0700 http://www.odeo.com/episodes/24537018-Feathers One of the most complex body coverings, feathers are truly amazing things. One of the most complex body coverings, feathers are truly amazing things. One of the most complex body coverings, feathers are truly amazing things. tag:odeo.com,2009-05-04,24537018 Mon, 04 May 2009 10:30:57 -0700 no Experiment of the Week Science, birds, School and Education, krampf, feathers http://www.odeo.com/episodes/24506455-Bird-on-a-Wire How can birds sit on power lines without getting shocked? How can birds sit on power lines without getting shocked? How can birds sit on power lines without getting shocked? tag:odeo.com,2009-04-26,24506455 Sun, 26 Apr 2009 08:26:44 -0700 no Experiment of the Week Technology, Science, experiment, electricity, krampf http://www.odeo.com/episodes/25335411-Solar-Power Visiting the world's largest solar power plants to explore reflection and refraction. Visiting the world's largest solar power plants to explore reflection and refraction. Visiting the world's largest solar power plants to explore reflection and refraction. tag:odeo.com,2009-04-13,25335411 Mon, 13 Apr 2009 10:14:30 -0700 no Experiment of the Week Science, power, experiment, light, solar, School and Education, krampf, reflect, refract http://www.odeo.com/episodes/25335418-Just-a-Suggestion Can you watch the entire video without scratching your nose? Can you watch the entire video without scratching your nose? Can you watch the entire video without scratching your nose? tag:odeo.com,2009-04-13,25335418 Mon, 13 Apr 2009 10:14:01 -0700 no Experiment of the Week Science, Brain, trick, experiment, School and Education, krampf http://www.odeo.com/episodes/24442981-Solar-Power Visiting the world's largest solar power plants to explore reflection and refraction. Visiting the world's largest solar power plants to explore reflection and refraction. Visiting the world's largest solar power plants to explore reflection and refraction. tag:odeo.com,2009-04-13,24442981 Mon, 13 Apr 2009 09:14:30 -0700 no Experiment of the Week Science, power, experiment, light, solar, School and Education, krampf, reflect, refract http://www.odeo.com/episodes/24442987-Just-a-Suggestion Can you watch the entire video without scratching your nose? Can you watch the entire video without scratching your nose? Can you watch the entire video without scratching your nose? tag:odeo.com,2009-04-13,24442987 Mon, 13 Apr 2009 09:14:01 -0700 no Experiment of the Week Science, Brain, trick, experiment, School and Education, krampf http://www.odeo.com/episodes/23744427-Static-Charges An introduction to induction. A quick look at static charges and how they are produced. An introduction to induction. A quick look at static charges and how they are produced. An introduction to induction. A quick look at static charges and how they are produced. tag:odeo.com,2008-12-12,23744427 Fri, 12 Dec 2008 05:11:51 -0800 no Experiment of the Week Science http://www.odeo.com/episodes/23675224-Why-Wet-Things-Won-t-Burn Why won't wet things burn? It sounds like a simple question, until you try to answer it. Why won't wet things burn? It sounds like a simple question, until you try to answer it. Why won't wet things burn? It sounds like a simple question, until you try to answer it. tag:odeo.com,2008-11-26,23675224 Wed, 26 Nov 2008 18:55:10 -0800 no Experiment of the Week Science http://www.odeo.com/episodes/23591745-Science-Fair-Panic-Part-4 What if something goes WRONG with your project?!?! What if something goes WRONG with your project?!?! What if something goes WRONG with your project?!?! tag:odeo.com,2008-11-07,23591745 Fri, 07 Nov 2008 08:29:17 -0800 no Experiment of the Week Science http://www.odeo.com/episodes/23549812-Science-Fair-Panic-Part-3 This time we look at designing a good experiment, especially on controlling variables. This time we look at designing a good experiment, especially on controlling variables. This time we look at designing a good experiment, especially on controlling variables. tag:odeo.com,2008-10-29,23549812 Wed, 29 Oct 2008 21:34:17 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23518108-Science-Fair-Panic-Part-2 Continuing on last week's video, this time we will learn how to form your hypothesis. Continuing on last week's video, this time we will learn how to form your hypothesis. Continuing on last week's video, this time we will learn how to form your hypothesis. tag:odeo.com,2008-10-22,23518108 Wed, 22 Oct 2008 12:13:46 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23493829-Science-Fair-Panic-Part-1 Well, its getting close to science fair time. Before you panic, slow down and set some goals. Well, its getting close to science fair time. Before you panic, slow down and set some goals. Well, its getting close to science fair time. Before you panic, slow down and set some goals. tag:odeo.com,2008-10-16,23493829 Thu, 16 Oct 2008 06:40:50 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23467439-Hydrothermal-Quartz How can hot water form beautiful quartz crystals? How can hot water form beautiful quartz crystals? How can hot water form beautiful quartz crystals? tag:odeo.com,2008-10-08,23467439 Wed, 08 Oct 2008 06:48:40 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23445681-Chromatography Can you tell which pen was used to write a note? Of course you can, if you know the science of chromatography. Can you tell which pen was used to write a note? Of course you can, if you know the science of chromatography. Can you tell which pen was used to write a note? Of course you can, if you know the science of chromatography. tag:odeo.com,2008-10-02,23445681 Thu, 02 Oct 2008 17:02:55 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23412061-White-Balance Have you ever taken a photograph and found that all the colors were either too yellow or too blue? If you understand the science behind white balance, you will know why. Have you ever taken a photograph and found that all the colors were either too yellow or too blue? If you understand the science behind white balance, you will know why. Have you ever taken a photograph and found that all the colors were either too yellow or too blue? If you understand the science behind white balance, you will know why. tag:odeo.com,2008-09-27,23412061 Sat, 27 Sep 2008 06:16:48 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23394397-White-Balance Have you ever taken a photo that turned out yellowish or with a blue tint? After watching this, you will understand why. Have you ever taken a photo that turned out yellowish or with a blue tint? After watching this, you will understand why. Have you ever taken a photo that turned out yellowish or with a blue tint? After watching this, you will understand why. tag:odeo.com,2008-09-24,23394397 Wed, 24 Sep 2008 13:20:07 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23369087-Testing-for-Tannic-Acid Try this simple test to detect tannic acid in your food. Try this simple test to detect tannic acid in your food. Try this simple test to detect tannic acid in your food. tag:odeo.com,2008-09-18,23369087 Thu, 18 Sep 2008 05:53:18 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23326188-More-Science-of-Balance Make this fun science toy and explore the science of balance. Make this fun science toy and explore the science of balance. Make this fun science toy and explore the science of balance. tag:odeo.com,2008-09-09,23326188 Tue, 09 Sep 2008 19:37:31 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23245206-Raw-Egg-or-Boiled You can easily tell if an egg is raw or hard boiled without breaking the shell, as long as you know a little science. You can easily tell if an egg is raw or hard boiled without breaking the shell, as long as you know a little science. You can easily tell if an egg is raw or hard boiled without breaking the shell, as long as you know a little science. tag:odeo.com,2008-09-03,23245206 Wed, 03 Sep 2008 08:08:51 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23220711-Science-of-Balance How do you balance? If you understand center of gravity and base, balancing is easy. How do you balance? If you understand center of gravity and base, balancing is easy. How do you balance? If you understand center of gravity and base, balancing is easy. tag:odeo.com,2008-08-27,23220711 Wed, 27 Aug 2008 07:49:19 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23197924-Light-Speed-Chocolate Continuing from last week's experiment, you can use your microwave oven and some chocolate bars to measure the speed of light. Continuing from last week's experiment, you can use your microwave oven and some chocolate bars to measure the speed of light. Continuing from last week's experiment, you can use your microwave oven and some chocolate bars to measure the speed of light. tag:odeo.com,2008-08-20,23197924 Wed, 20 Aug 2008 12:18:48 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23176771-Microwave-Chocolate Combine science and chocolate to learn about how microwave ovens work. Combine science and chocolate to learn about how microwave ovens work. Combine science and chocolate to learn about how microwave ovens work. tag:odeo.com,2008-08-13,23176771 Wed, 13 Aug 2008 10:33:17 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23152234-Air-Space Ever tried to fit a week's clothing into a small suitcase? How much of what you were packing was air? Try this simple experiment to see how much of your packing space is air. Ever tried to fit a week's clothing into a small suitcase? How much of what you were packing was air? Try this simple experiment to see how much of your packing space is air. Ever tried to fit a week's clothing into a small suitcase? How much of what you were packing was air? Try this simple experiment to see how much of your packing space is air. tag:odeo.com,2008-08-06,23152234 Wed, 06 Aug 2008 09:24:21 -0700 no Experiment of the Week Space, Science, experiment, air, krampf http://www.odeo.com/episodes/23126238-The-Waterfall-Effect Try this natural, optical illusion, which tricks your eyes with motion, instead of with colors or distortions. Try this natural, optical illusion, which tricks your eyes with motion, instead of with colors or distortions. Try this natural, optical illusion, which tricks your eyes with motion, instead of with colors or distortions. tag:odeo.com,2008-07-29,23126238 Tue, 29 Jul 2008 19:14:57 -0700 no Experiment of the Week Science, experiment, optical, illusion, krampf http://www.odeo.com/episodes/23108359-Ice-Cream-Science As Robert continues his journey across the country, he uses some science to make a cold, tasty snack. As Robert continues his journey across the country, he uses some science to make a cold, tasty snack. As Robert continues his journey across the country, he uses some science to make a cold, tasty snack. tag:odeo.com,2008-07-22,23108359 Tue, 22 Jul 2008 21:32:21 -0700 no Experiment of the Week energy, Science, experiment, krampf http://www.odeo.com/episodes/23083367-Relative-Motion How fast are you traveling? Probably a lot faster than you think. How fast are you traveling? Probably a lot faster than you think. How fast are you traveling? Probably a lot faster than you think. tag:odeo.com,2008-07-16,23083367 Wed, 16 Jul 2008 10:02:07 -0700 no Experiment of the Week Science http://www.odeo.com/episodes/23064550-Oxygen-No Learn the science that will let you understand a frequently misunderstood experiment. Learn the science that will let you understand a frequently misunderstood experiment. Learn the science that will let you understand a frequently misunderstood experiment. tag:odeo.com,2008-07-09,23064550 Wed, 09 Jul 2008 15:29:27 -0700 no Experiment of the Week Science, experiment, Oxygen, krampf http://www.odeo.com/episodes/23049533-Pictures-in-Silver Try this simple experiment to see some of the chemistry of photography. Try this simple experiment to see some of the chemistry of photography. Try this simple experiment to see some of the chemistry of photography. tag:odeo.com,2008-07-02,23049533 Wed, 02 Jul 2008 07:55:28 -0700 no Experiment of the Week Science, chemistry, photography, experiment, krampf http://www.odeo.com/episodes/23008264-Looking-for-Rainbows Want to know how to find the perfect spot for taking great rainbow photos? You just need to know a little of the science of rainbows. Want to know how to find the perfect spot for taking great rainbow photos? You just need to know a little of the science of rainbows. Want to know how to find the perfect spot for taking great rainbow photos? You just need to know a little of the science of rainbows. tag:odeo.com,2008-06-19,23008264 Thu, 19 Jun 2008 15:44:32 -0700 no Experiment of the Week Science, light, rainbow, science experiment, robert krampf http://www.odeo.com/episodes/22585583-Making-Butter Learn about science as you make your own butter. Science has never tasted so good. Learn about science as you make your own butter. Science has never tasted so good. Learn about science as you make your own butter. Science has never tasted so good. tag:odeo.com,2008-06-04,22585583 Wed, 04 Jun 2008 20:15:27 -0700 no Experiment of the Week Food, Science, experiment, Robert, School and Education, butter, krampf http://www.odeo.com/episodes/22562673-Is-That-a-Color-Photo Trick your eyes and your brain into seeing color in a black and white photo. Trick your eyes and your brain into seeing color in a black and white photo. Trick your eyes and your brain into seeing color in a black and white photo. tag:odeo.com,2008-05-28,22562673 Wed, 28 May 2008 11:34:03 -0700 no Experiment of the Week Science, experiment, Robert, Vision, light, School and Education, color, krampf http://www.odeo.com/episodes/22531106-Milk-Bubbles Learn about surface tension while blowing bubbles in your milk. Learn about surface tension while blowing bubbles in your milk. Learn about surface tension while blowing bubbles in your milk. tag:odeo.com,2008-05-21,22531106 Wed, 21 May 2008 06:06:21 -0700 no Experiment of the Week Science, experiment, Robert, School and Education, tension, krampf, bubbles, surface http://www.odeo.com/episodes/22515436-Extra-Oxygen Try this experiment to see how adding extra oxygen makes things burn faster. Try this experiment to see how adding extra oxygen makes things burn faster. Try this experiment to see how adding extra oxygen makes things burn faster. tag:odeo.com,2008-05-14,22515436 Wed, 14 May 2008 19:48:22 -0700 no Experiment of the Week Technology, Science, experiment, combustion, Robert, Oxygen, krampf http://www.odeo.com/episodes/22492540-Nature-Watching Practice your observational skills while watching wildlife. Practice your observational skills while watching wildlife. Practice your observational skills while watching wildlife. tag:odeo.com,2008-05-08,22492540 Thu, 08 May 2008 04:35:11 -0700 no Experiment of the Week Science, birds, Nature, The Environment, Robert, krampf http://www.odeo.com/episodes/22480696-Density-Column Learn about why things float while having fun with density. Learn about why things float while having fun with density. Learn about why things float while having fun with density. tag:odeo.com,2008-04-30,22480696 Wed, 30 Apr 2008 20:04:07 -0700 no Experiment of the Week Science, experiment, Robert, density, School and Education, krampf http://www.odeo.com/episodes/22480697-Why-Things-Go-Bang Learn why fireworks, lightning and popcorn make loud sounds. Learn why fireworks, lightning and popcorn make loud sounds. Learn why fireworks, lightning and popcorn make loud sounds. tag:odeo.com,2008-04-24,22480697 Thu, 24 Apr 2008 12:42:50 -0700 no Experiment of the Week Science, Sound, experiment, Robert, School and Education, krampf http://www.odeo.com/episodes/22480698-Ice-and-String Can you lift an ice cube out of a bowl of water with a piece of string? Of course you can, if you know a little science, and have a little salt. Can you lift an ice cube out of a bowl of water with a piece of string? Of course you can, if you know a little science, and have a little salt. Can you lift an ice cube out of a bowl of water with a piece of string? Of course you can, if you know a little science, and have a little salt. tag:odeo.com,2008-04-16,22480698 Wed, 16 Apr 2008 07:17:47 -0700 no Experiment of the Week energy, School and Education, states, matter http://www.odeo.com/episodes/22480699-Light-as-Air You've heard people say that something is as light as air. How light is air? Probably a lot heavier than you think. Try this simple, fun way to calculate the weight of the air in your room. You've heard people say that something is as light as air. How light is air? Probably a lot heavier than you think. Try this simple, fun way to calculate the weight of the air in your room. You've heard people say that something is as light as air. How light is air? Probably a lot heavier than you think. Try this simple, fun way to calculate the weight of the air in your room. tag:odeo.com,2008-04-09,22480699 Wed, 09 Apr 2008 06:39:24 -0700 no Experiment of the Week Science, experiment, Robert, air, density, School and Education, krampf http://www.odeo.com/episodes/22480700-Measuring-Lightning Try this simple way to measure not only how far away the lightning was, but also about how long the bolt was. Try this simple way to measure not only how far away the lightning was, but also about how long the bolt was. Try this simple way to measure not only how far away the lightning was, but also about how long the bolt was. tag:odeo.com,2008-04-01,22480700 Tue, 01 Apr 2008 18:38:10 -0700 no Experiment of the Week Science, experiment, School and Education, thunder, lightning, krampf http://www.odeo.com/episodes/22480701-Selective-Smelling You've heard of optical illusions, but have you ever tried a "nose illusion"? You've heard of optical illusions, but have you ever tried a "nose illusion"? You've heard of optical illusions, but have you ever tried a "nose illusion"? tag:odeo.com,2008-03-26,22480701 Wed, 26 Mar 2008 02:03:17 -0700 no Experiment of the Week Science, experiment, Robert, School and Education, senses, krampf http://www.odeo.com/episodes/22480702-Noisy-String Try this fun way to learn about sound and vibration, while making lots of strange sounds. Try this fun way to learn about sound and vibration, while making lots of strange sounds. Try this fun way to learn about sound and vibration, while making lots of strange sounds. tag:odeo.com,2008-03-19,22480702 Wed, 19 Mar 2008 06:56:01 -0700 no Experiment of the Week Science, Sound, experiment, School and Education, vibration, krampf http://www.odeo.com/episodes/22480703-Hanging-a-Hammer Can you balance a hammer, a ruler, and a piece of string on the edge of a table? Of course you can. Can you balance a hammer, a ruler, and a piece of string on the edge of a table? Of course you can. Can you balance a hammer, a ruler, and a piece of string on the edge of a table? Of course you can. tag:odeo.com,2008-03-12,22480703 Wed, 12 Mar 2008 04:40:25 -0700 no Experiment of the Week tricks, Science, machines, simple, Robert, gravity, School and Education, krampf http://www.odeo.com/episodes/22480704-Planets-and-Pennies Use this simple science experiment to see how the pull of gravity varies on different plantes. Use this simple science experiment to see how the pull of gravity varies on different plantes. Use this simple science experiment to see how the pull of gravity varies on different plantes. tag:odeo.com,2008-03-06,22480704 Thu, 06 Mar 2008 06:47:09 -0800 no Experiment of the Week Science, planets, experiment, gravity, School and Education, krampf http://www.odeo.com/episodes/22480705-About-Microwaves This week's experiment came from a question asked by a student during my energy show. He wanted to know how microwave ovens work. For this experiment, you will need: 3 identical, microwave safe containerswatercooking oila microwave oven I used small drinking glasses, but any microwave safe containers should work. Put about an inch of water into one glass, about an inch of cooking oil into another and left the third glass empty. Place all three glasses into the microwave oven. Set the time for 15 seconds and start the oven. When the oven stops, open the door and carefully remove all three glasses. Carefully feel the outside of the glass of water, at the water level. It should feel quite warm. Making sure not to burn yourself, carefully touch the surface of the water. It should also be quite warm, possibly even hot. Do the same thing with the glass of cooking oil and the empty glass. What do you notice? The glass of water heated up nicely, but the glass of oil, and the empty glass did... This week's experiment came from a question asked by a student during my energy show. He wanted to know how microwave ovens work. For this experiment, you will need: 3 identical, microwave safe containerswatercooking oila microwave oven I used small drinking glasses, but any microwave safe containers should work. Put about an inch of water into one glass, about an inch of cooking oil into another and left the third glass empty. Place all three glasses into the microwave oven. Set the time for 15 seconds and start the oven. When the oven stops, open the door and carefully remove all three glasses. Carefully feel the outside of the glass of water, at the water level. It should feel quite warm. Making sure not to burn yourself, carefully touch the surface of the water. It should also be quite warm, possibly even hot. Do the same thing with the glass of cooking oil and the empty glass. What do you notice? The glass of water heated up nicely, but the glass of oil, and the empty glass did not. Why? It has to do with how a microwave oven works. Inside the oven is a tube called a magnetron. This magnetron broadcasts microwave radiation. RADIATION!!!! Oh, no! Is my food radioactive? No. There are many kinds of electromagnetic radiation, such as radio, television, radar, and light. Microwaves do not make your food radioactive. So how to the microwaves cook your food? They cause the water molecules in the food to vibrate. Why just the water molecules? Water molecules are polar. That means that one end of the water molecule has a positive charge and the other end has a negative charge. As the name suggests, microwaves are waves. They are not waves of water, but waves of electromagnetic energy. Just as a wave in water can cause an object to bob up and down, the microwaves can cause a molecule of water to vibrate first one way and then the other. As the wave approaches the molecule, the positive end is pulled one way and the negative end is pulled in the opposite direction. As the wave passes, the pulls are reversed. This causes the water molecule to vibrate back and forth rapidly, which makes it hot. The water molecule then passes some of the vibration to surrounding molecules, making them hot too. Oil is not a polar molecule. That is the reason that oil and water do not mix easily. Polar molecules stick to other polar molecules, but not to nonpolar ones. Because the oil is not polar, it is not heated by the microwaves. That is why we cannot fry things in the microwave. But wait a minute. I have had bacon cooked in the microwave. What about that? The bacon contains water as well as the fat. The water in the strip of bacon provides the heat to cook it. The fat just drains away. It will be hot, having been heated by the water in the bacon, but it will not continue heating once it drains away. Dry foods do not cook well in the microwave oven. Remember that the empty glass did not get hot. You need the polar molecules in the water to get the heat for cooking. Now, lets get back to the RADIATION. You might have heard that microwaves change the chemical structure of the food. Yes, cooking food with microwaves does change the chemical structure of the food. So does any kind of cooking. That is the reason we cook food. If you don't want the chemical structure of your food changed, eat it raw. Food cooked in a microwave oven is just as nutritious as food cooked by other means. It is not radioactive and not dangerous, as long as you don't burn yourself with it or drop it on your foot. On second thought, if you count eating too many microwave brownies as dangerous, then you could count my microwave as a hazard area. Have a great week. This week's experiment came from a question asked by a student during my energy show. He wanted to know how microwave ovens work. For this experiment, you will need: 3 identical, microwave safe containerswatercooking oila microwave oven I used small drinking glasses, but any microwave safe containers should work. Put about an inch of water into one glass, about an inch of cooking oil into another and left the third glass empty. Place all three glasses into the microwave oven. Set the time for 15 seconds and start the oven. When the oven stops, open the door and carefully remove all three glasses. Carefully feel the outside of the glass of water, at the water level. It should feel quite warm. Making sure not to burn yourself, carefully touch the surface of the water. It should also be quite warm, possibly even hot. Do the same thing with the glass of cooking oil and the empty glass. What do you notice? The glass of water heated up nicely, but the glass of oil, and the empty glass did not. Why? It has to do with how a microwave oven works. Inside the oven is a tube called a magnetron. This magnetron broadcasts microwave radiation. RADIATION!!!! Oh, no! Is my food radioactive? No. There are many kinds of electromagnetic radiation, such as radio, television, radar, and light. Microwaves do not make your food radioactive. So how to the microwaves cook your food? They cause the water molecules in the food to vibrate. Why just the water molecules? Water molecules are polar. That means that one end of the water molecule has a positive charge and the other end has a negative charge. As the name suggests, microwaves are waves. They are not waves of water, but waves of electromagnetic energy. Just as a wave in water can cause an object to bob up and down, the microwaves can cause a molecule of water to vibrate first one way and then the other. As the wave approaches the molecule, the positive end is pulled one way and the negative end is pulled in the opposite direction. As the wave passes, the pulls are reversed. This causes the water molecule to vibrate back and forth rapidly, which makes it hot. The water molecule then passes some of the vibration to surrounding molecules, making them hot too. Oil is not a polar molecule. That is the reason that oil and water do not mix easily. Polar molecules stick to other polar molecules, but not to nonpolar ones. Because the oil is not polar, it is not heated by the microwaves. That is why we cannot fry things in the microwave. But wait a minute. I have had bacon cooked in the microwave. What about that? The bacon contains water as well as the fat. The water in the strip of bacon provides the heat to cook it. The fat just drains away. It will be hot, having been heated by the water in the bacon, but it will not continue heating once it drains away. Dry foods do not cook well in the microwave oven. Remember that the empty glass did not get hot. You need the polar molecules in the water to get the heat for cooking. Now, lets get back to the RADIATION. You might have heard that microwaves change the chemical structure of the food. Yes, cooking food with microwaves does change the chemical structure of the food. So does any kind of cooking. That is the reason we cook food. If you don't want the chemical structure of your food changed, eat it raw. Food cooked in a microwave oven is just as nutritious as food cooked by other means. It is not radioactive and not dangerous, as long as you don't burn yourself with it or drop it on your foot. On second thought, if you count eating too many microwave brownies as dangerous, then you could count my microwave as a hazard area. Have a great week. tag:odeo.com,2008-02-06,22480705 Wed, 06 Feb 2008 14:05:01 -0800 no Experiment of the Week energy, Science, molecules, electromagnetic waves http://www.odeo.com/episodes/22480706-Flame-Color Have you ever wondered why some flames are yellow, while others are blue? Growing up, I was always told that it was a matter of temperature, that hot flames were blue and cooler flames were yellow. While there is a temperature difference, that difference is a "symptom" of what is going on, not the cause of the color difference. For this experiment, you will need: a candle with a holder. This can be as simple as some aluminum foil balled up around the base of the candle and flattened on the bottom. a lighter a wooden toothpick a white plate As we will see, even though the candle flame looks yellow, it is not. The actual flame is blue. You can see this by lighting the candle and looking very closely (not too close or you could lose your eyebrows!) at the base of the flame. Along the outer edge, you will see a thin, blue edge to the flame. It helps to be in a dark room. This is the color of the actual flame. The yellow color is caused by solid material burning inside the flame. When a ... Have you ever wondered why some flames are yellow, while others are blue? Growing up, I was always told that it was a matter of temperature, that hot flames were blue and cooler flames were yellow. While there is a temperature difference, that difference is a "symptom" of what is going on, not the cause of the color difference. For this experiment, you will need: a candle with a holder. This can be as simple as some aluminum foil balled up around the base of the candle and flattened on the bottom. a lighter a wooden toothpick a white plate As we will see, even though the candle flame looks yellow, it is not. The actual flame is blue. You can see this by lighting the candle and looking very closely (not too close or you could lose your eyebrows!) at the base of the flame. Along the outer edge, you will see a thin, blue edge to the flame. It helps to be in a dark room. This is the color of the actual flame. The yellow color is caused by solid material burning inside the flame. When a solid burns, it does not produce a flame. Instead it glows. You have probably see this glow on burning charcoal. You can also see it by carefully lighting the end of a wooden toothpick and then blowing out the flame. You will see the orange glow of glowing combustion at the tip of the burned toothpick. Does that mean that there is solid stuff inside the candle flame? Let's find out. Light the candle and be sure it is steady and won't fall over. Hold the bottom of the plate in the candle flame for a few seconds. When you remove the plate, it has turned black!!! Don't worry. You have not ruined it. Let it cool for a minute. Remember, it is HOT! Once it has cooled, rub your finger over the black spot. The black rubs off. Now, go wash your hands, to get rid of the black stuff. What is that black stuff? It is called carbon and it comes from the candle wax. As the candle burns, the wax comes apart to form several chemicals. One of these chemicals is carbon. The tiny bits of carbon burn inside the candle flame, giving off the yellow glow. If the candle wax did not produce this carbon, the candle flame would be blue, like the flame of a gas stove. You may have noticed some black smoke while the plate was in the flame. That smoke was made up of the tiny bits of carbon. Normally, the carbon burns, combining with oxygen to form carbon dioxide, a colorless gas. The spoon let some of the carbon get out of the flame without burning, producing smoke instead. When you see black smoke coming from a fire, it is usually made up of tiny bits of carbon. Have you ever wondered why some flames are yellow, while others are blue? Growing up, I was always told that it was a matter of temperature, that hot flames were blue and cooler flames were yellow. While there is a temperature difference, that difference is a "symptom" of what is going on, not the cause of the color difference. For this experiment, you will need: a candle with a holder. This can be as simple as some aluminum foil balled up around the base of the candle and flattened on the bottom. a lighter a wooden toothpick a white plate As we will see, even though the candle flame looks yellow, it is not. The actual flame is blue. You can see this by lighting the candle and looking very closely (not too close or you could lose your eyebrows!) at the base of the flame. Along the outer edge, you will see a thin, blue edge to the flame. It helps to be in a dark room. This is the color of the actual flame. The yellow color is caused by solid material burning inside the flame. When a solid burns, it does not produce a flame. Instead it glows. You have probably see this glow on burning charcoal. You can also see it by carefully lighting the end of a wooden toothpick and then blowing out the flame. You will see the orange glow of glowing combustion at the tip of the burned toothpick. Does that mean that there is solid stuff inside the candle flame? Let's find out. Light the candle and be sure it is steady and won't fall over. Hold the bottom of the plate in the candle flame for a few seconds. When you remove the plate, it has turned black!!! Don't worry. You have not ruined it. Let it cool for a minute. Remember, it is HOT! Once it has cooled, rub your finger over the black spot. The black rubs off. Now, go wash your hands, to get rid of the black stuff. What is that black stuff? It is called carbon and it comes from the candle wax. As the candle burns, the wax comes apart to form several chemicals. One of these chemicals is carbon. The tiny bits of carbon burn inside the candle flame, giving off the yellow glow. If the candle wax did not produce this carbon, the candle flame would be blue, like the flame of a gas stove. You may have noticed some black smoke while the plate was in the flame. That smoke was made up of the tiny bits of carbon. Normally, the carbon burns, combining with oxygen to form carbon dioxide, a colorless gas. The spoon let some of the carbon get out of the flame without burning, producing smoke instead. When you see black smoke coming from a fire, it is usually made up of tiny bits of carbon. tag:odeo.com,2008-01-30,22480706 Wed, 30 Jan 2008 08:29:31 -0800 no Experiment of the Week energy, Science, fire, combustion http://www.odeo.com/episodes/22480707-Two-Candles-part-2 Hopefully you spent some time stuck in traffic to think about last week's experiment. Did you actually try it? Very good! If you did, you saw that the tall candle goes out before the short one. Why? First, lets think about what is happening as the candle burns. Oxygen from the air is combining with the carbon and hydrogen from the candle wax, to form carbon dioxide and water vapor. During this process, chemical energy in the wax is converted into the light and heat energy of the flame. If the supply of oxygen runs low, then the candle flame gets smaller and goes out. But why would the tall candle go out first? The carbon dioxide and water vapor do not mix evenly in the bottle. They are quite a bit hotter than the air in the bottle, so they spread out, and are less dense. This causes them to rise to the top of the bottle. Think of it like filling the bottle with water, only in reverse. Water is denser than air, so if you poured water into the bottle, it would go to the bottom. As you... Hopefully you spent some time stuck in traffic to think about last week's experiment. Did you actually try it? Very good! If you did, you saw that the tall candle goes out before the short one. Why? First, lets think about what is happening as the candle burns. Oxygen from the air is combining with the carbon and hydrogen from the candle wax, to form carbon dioxide and water vapor. During this process, chemical energy in the wax is converted into the light and heat energy of the flame. If the supply of oxygen runs low, then the candle flame gets smaller and goes out. But why would the tall candle go out first? The carbon dioxide and water vapor do not mix evenly in the bottle. They are quite a bit hotter than the air in the bottle, so they spread out, and are less dense. This causes them to rise to the top of the bottle. Think of it like filling the bottle with water, only in reverse. Water is denser than air, so if you poured water into the bottle, it would go to the bottom. As you added more water, the level would rise, until it put out the shortest candle. Now reverse that. The hot carbon dioxide and water vapor rise to the top of the bottle. As the flame produces more and more of the hot gases, their level moves downward from the top, until it reaches the tallest flame. As the flame is surrounded, it runs out of oxygen and goes out. The shorter candle is still surrounded by the denser, oxygen rich air, so it continues to burn for a while longer. I hope you really did try the experiment. It is much more fun when you actually do things instead of just reading about them. For example, it is interesting to read about a large bowl of ice cream, covered with hot fudge sauce and a sprinkle of chopped pecans, but it is so much better to actually experience it yourself. Sounds like a great idea to me. Have a wonder filled week. Hopefully you spent some time stuck in traffic to think about last week's experiment. Did you actually try it? Very good! If you did, you saw that the tall candle goes out before the short one. Why? First, lets think about what is happening as the candle burns. Oxygen from the air is combining with the carbon and hydrogen from the candle wax, to form carbon dioxide and water vapor. During this process, chemical energy in the wax is converted into the light and heat energy of the flame. If the supply of oxygen runs low, then the candle flame gets smaller and goes out. But why would the tall candle go out first? The carbon dioxide and water vapor do not mix evenly in the bottle. They are quite a bit hotter than the air in the bottle, so they spread out, and are less dense. This causes them to rise to the top of the bottle. Think of it like filling the bottle with water, only in reverse. Water is denser than air, so if you poured water into the bottle, it would go to the bottom. As you added more water, the level would rise, until it put out the shortest candle. Now reverse that. The hot carbon dioxide and water vapor rise to the top of the bottle. As the flame produces more and more of the hot gases, their level moves downward from the top, until it reaches the tallest flame. As the flame is surrounded, it runs out of oxygen and goes out. The shorter candle is still surrounded by the denser, oxygen rich air, so it continues to burn for a while longer. I hope you really did try the experiment. It is much more fun when you actually do things instead of just reading about them. For example, it is interesting to read about a large bowl of ice cream, covered with hot fudge sauce and a sprinkle of chopped pecans, but it is so much better to actually experience it yourself. Sounds like a great idea to me. Have a wonder filled week. tag:odeo.com,2008-01-22,22480707 Tue, 22 Jan 2008 08:18:27 -0800 no Experiment of the Week Science, carbon dioxide, combustion, density, scientific thought http://www.odeo.com/episodes/22480708-Two-Candles-1 This experiment will give your brain some exercise, and will really get you thinking about air. You will need: 2 candlesa lightera glass jar at least 3 inches taller than the candlesfoila knife Use the knife to cut one of the candles so that it is at least 2 inches shorter than the other. The other option is to find candles that are different heights to start with. Crumple the foil around the base of the candles to hold them upright, side by side. We are going to light both candles, and then place the jar over them, but first lets think about what is going to happen. What do you think will happen? As the candles use up the oxygen in the jar, will both of them go out at the same time? If one goes out first, will it be the tall one or the short one? Why? Think about it first, before you actually try it. OK, have you thought about it? Have you formed a hypothesis? That means not just guessing which one will go out when, but actually coming up with a logical explanation for what you thi... This experiment will give your brain some exercise, and will really get you thinking about air. You will need: 2 candlesa lightera glass jar at least 3 inches taller than the candlesfoila knife Use the knife to cut one of the candles so that it is at least 2 inches shorter than the other. The other option is to find candles that are different heights to start with. Crumple the foil around the base of the candles to hold them upright, side by side. We are going to light both candles, and then place the jar over them, but first lets think about what is going to happen. What do you think will happen? As the candles use up the oxygen in the jar, will both of them go out at the same time? If one goes out first, will it be the tall one or the short one? Why? Think about it first, before you actually try it. OK, have you thought about it? Have you formed a hypothesis? That means not just guessing which one will go out when, but actually coming up with a logical explanation for what you think will happen. Now it is time to test your hypothesis. In other words, do the experiment! OK, what happened? (Did you think that I was going to tell you?) Yes, I know that at this point I usually explain things, but now and then it is fun to let you try the experiment without knowing beforehand how it will turn out. Don't worry. All you have to do is try it and you will find out, or wait until next week. This experiment will give your brain some exercise, and will really get you thinking about air. You will need: 2 candlesa lightera glass jar at least 3 inches taller than the candlesfoila knife Use the knife to cut one of the candles so that it is at least 2 inches shorter than the other. The other option is to find candles that are different heights to start with. Crumple the foil around the base of the candles to hold them upright, side by side. We are going to light both candles, and then place the jar over them, but first lets think about what is going to happen. What do you think will happen? As the candles use up the oxygen in the jar, will both of them go out at the same time? If one goes out first, will it be the tall one or the short one? Why? Think about it first, before you actually try it. OK, have you thought about it? Have you formed a hypothesis? That means not just guessing which one will go out when, but actually coming up with a logical explanation for what you think will happen. Now it is time to test your hypothesis. In other words, do the experiment! OK, what happened? (Did you think that I was going to tell you?) Yes, I know that at this point I usually explain things, but now and then it is fun to let you try the experiment without knowing beforehand how it will turn out. Don't worry. All you have to do is try it and you will find out, or wait until next week. tag:odeo.com,2008-01-16,22480708 Wed, 16 Jan 2008 07:14:50 -0800 no Experiment of the Week Science, carbon dioxide, combustion, density, scientific thought http://www.odeo.com/episodes/22480709-Ice-and-Soda This week's experiment is a fun trick that is useful too. How can you pour a glass of soda without getting a glass that is half soda and half foam? To find out, you will need: 2 glassesicecarbonated soda Take some ice straight from the freezer. Put a few cubes into a glass and pour in some carbonated soda. You will get lots of foam and fizz. Next, put some more ice into the second glass. This time, fill the glass with water and then pour the water out. Pour in the carbonated soda and observe. This time, there is much less foam. What is happening? What is the difference between ice fresh from the freezer and "wet" ice? Comparing the surfaces of the two, the wet ice is much smoother. The fresh ice has a surface with lots of rough spots and irregularities. Why would this make a difference? The carbonated soda is a liquid with a gas dissolved in it. This gas (carbon dioxide) easily comes out of solution, forming bubbles. Rough surfaces give the gas bubbles a better place to form, produc... This week's experiment is a fun trick that is useful too. How can you pour a glass of soda without getting a glass that is half soda and half foam? To find out, you will need: 2 glassesicecarbonated soda Take some ice straight from the freezer. Put a few cubes into a glass and pour in some carbonated soda. You will get lots of foam and fizz. Next, put some more ice into the second glass. This time, fill the glass with water and then pour the water out. Pour in the carbonated soda and observe. This time, there is much less foam. What is happening? What is the difference between ice fresh from the freezer and "wet" ice? Comparing the surfaces of the two, the wet ice is much smoother. The fresh ice has a surface with lots of rough spots and irregularities. Why would this make a difference? The carbonated soda is a liquid with a gas dissolved in it. This gas (carbon dioxide) easily comes out of solution, forming bubbles. Rough surfaces give the gas bubbles a better place to form, producing more foam. You can see this by trying another rough surface, some grains of sugar. When you sprinkle the grains of sugar into the soda, it foams up. If you dissolve the sugar in a little water, you can add the solution without the same level of foam. You could do the same thing with a little salt, but then you would not want to drink the soda afterwards. It would be a shame to let it go to waste. You would not believe how much soda I drank while researching this one. Sometimes we have to make sacrifices in the name of science. Have a wonder-filled week. This week's experiment is a fun trick that is useful too. How can you pour a glass of soda without getting a glass that is half soda and half foam? To find out, you will need: 2 glassesicecarbonated soda Take some ice straight from the freezer. Put a few cubes into a glass and pour in some carbonated soda. You will get lots of foam and fizz. Next, put some more ice into the second glass. This time, fill the glass with water and then pour the water out. Pour in the carbonated soda and observe. This time, there is much less foam. What is happening? What is the difference between ice fresh from the freezer and "wet" ice? Comparing the surfaces of the two, the wet ice is much smoother. The fresh ice has a surface with lots of rough spots and irregularities. Why would this make a difference? The carbonated soda is a liquid with a gas dissolved in it. This gas (carbon dioxide) easily comes out of solution, forming bubbles. Rough surfaces give the gas bubbles a better place to form, producing more foam. You can see this by trying another rough surface, some grains of sugar. When you sprinkle the grains of sugar into the soda, it foams up. If you dissolve the sugar in a little water, you can add the solution without the same level of foam. You could do the same thing with a little salt, but then you would not want to drink the soda afterwards. It would be a shame to let it go to waste. You would not believe how much soda I drank while researching this one. Sometimes we have to make sacrifices in the name of science. Have a wonder-filled week. tag:odeo.com,2008-01-09,22480709 Wed, 09 Jan 2008 12:30:37 -0800 no Experiment of the Week video, Science, gas, solution, coke, gases, mentos, school project, science experiment, diet coke http://www.odeo.com/episodes/22480710-Foot-Circles This week's experiment has made the rounds through the internet as a strange trick, but there is science here too. We are going to use the science of complex systems to confuse your body. To try this, you will need: your hands and feet Lift your right foot about 6 inches off the ground. Now start moving it in circles, clockwise. As you continue doing that, use your right hand to draw a number 6 in the air in front of you. As you do that, you will find that your foot has changed directions and is now going counterclockwise. Now, how did that happen? Although the experiment is easy, it is far from simple. It took quite a bit of digging to trace this trick back to Professor Haken and the science of Synergetics. This science deals with the ways that complex systems work. In a complex system such as your brain and nervous system, there are many different signals moving back and forth. Some of these signals are treated with more importance than others. Some of the signals also become coup... This week's experiment has made the rounds through the internet as a strange trick, but there is science here too. We are going to use the science of complex systems to confuse your body. To try this, you will need: your hands and feet Lift your right foot about 6 inches off the ground. Now start moving it in circles, clockwise. As you continue doing that, use your right hand to draw a number 6 in the air in front of you. As you do that, you will find that your foot has changed directions and is now going counterclockwise. Now, how did that happen? Although the experiment is easy, it is far from simple. It took quite a bit of digging to trace this trick back to Professor Haken and the science of Synergetics. This science deals with the ways that complex systems work. In a complex system such as your brain and nervous system, there are many different signals moving back and forth. Some of these signals are treated with more importance than others. Some of the signals also become coupled, with one signal guiding the other. That is what is happening with your foot and hand. Your hand movement couples with your foot movement, but your hand movement is treated with more importance, so your foot changes direction. Even more interesting is that you don't actually have to move your hand. Try the experiment again, but this time just think about drawing the number 6 in the air. Your foot will still reverse. The pattern of your thoughts still couples with the movement of your foot. For even more fun, try drawing a number 8. Redraw the number over and over in a continuous motion and you will find that your foot keeps switching back and forth. There are several variables in this experiment, so it may not work exactly for you the first time. If you find that it does not work well, trying circling your right foot while drawing the 6 with your left hand. Try reversing things, using your left foot and right hand, etc. Why do your body movements couple? Get up and walk slowly across the room. Pay close attention to all the movements involved in walking. Yes, your legs move, but so does the rest of your body. You shift your position slightly with each step, to keep your balance. What if you had to think consciously about the movement of every muscle? Walking would be a very slow and tedious process, just as it is for a baby learning to walk. Our bodies quickly learn to group all those motions into patterns, giving various levels of importance to each. Soon the patterns are automatic. As your foot steps forward, your body shifts to keep your center of gravity over the other foot. As you sit down, you lean forward, again to keep your balance. As you open the freezer, your hand grasps the ice cream container...... Have a wonder filled week. This week's experiment has made the rounds through the internet as a strange trick, but there is science here too. We are going to use the science of complex systems to confuse your body. To try this, you will need: your hands and feet Lift your right foot about 6 inches off the ground. Now start moving it in circles, clockwise. As you continue doing that, use your right hand to draw a number 6 in the air in front of you. As you do that, you will find that your foot has changed directions and is now going counterclockwise. Now, how did that happen? Although the experiment is easy, it is far from simple. It took quite a bit of digging to trace this trick back to Professor Haken and the science of Synergetics. This science deals with the ways that complex systems work. In a complex system such as your brain and nervous system, there are many different signals moving back and forth. Some of these signals are treated with more importance than others. Some of the signals also become coupled, with one signal guiding the other. That is what is happening with your foot and hand. Your hand movement couples with your foot movement, but your hand movement is treated with more importance, so your foot changes direction. Even more interesting is that you don't actually have to move your hand. Try the experiment again, but this time just think about drawing the number 6 in the air. Your foot will still reverse. The pattern of your thoughts still couples with the movement of your foot. For even more fun, try drawing a number 8. Redraw the number over and over in a continuous motion and you will find that your foot keeps switching back and forth. There are several variables in this experiment, so it may not work exactly for you the first time. If you find that it does not work well, trying circling your right foot while drawing the 6 with your left hand. Try reversing things, using your left foot and right hand, etc. Why do your body movements couple? Get up and walk slowly across the room. Pay close attention to all the movements involved in walking. Yes, your legs move, but so does the rest of your body. You shift your position slightly with each step, to keep your balance. What if you had to think consciously about the movement of every muscle? Walking would be a very slow and tedious process, just as it is for a baby learning to walk. Our bodies quickly learn to group all those motions into patterns, giving various levels of importance to each. Soon the patterns are automatic. As your foot steps forward, your body shifts to keep your center of gravity over the other foot. As you sit down, you lean forward, again to keep your balance. As you open the freezer, your hand grasps the ice cream container...... Have a wonder filled week. tag:odeo.com,2008-01-02,22480710 Wed, 02 Jan 2008 20:53:19 -0800 no Experiment of the Week biology, Science, Brain, human body http://www.odeo.com/episodes/22480711-Seed-Search I got the idea for this experiment while walking the dog. She always seems to pick up some burrs, and as I was picking them out, I realized that I was helping the plants that were causing me problems. To find out, you will need: 1. an area with some weeds 2. long pants 3. some cherries, plums, apples or other fruit with hard seeds First, look carefully at the weeds. Make sure that they don't contain any wasps, bees, snakes, lions or, tigers or bears, oh my. Once you are sure you will not disturb the local wildlife, walk through the weeds. Then carefully examine the legs of your pants. Depending on the time of year and the kinds of weeds in your area, there is a very good chance that you will find some burrs stuck to the cloth. Look at them carefully. The burrs that you found are actually seeds, intended to grow new plants. One problem that plants face is that they can't walk around. If a cherry tree could go for a walk, then it could drop its seeds here and there along the way, spre... I got the idea for this experiment while walking the dog. She always seems to pick up some burrs, and as I was picking them out, I realized that I was helping the plants that were causing me problems. To find out, you will need: 1. an area with some weeds 2. long pants 3. some cherries, plums, apples or other fruit with hard seeds First, look carefully at the weeds. Make sure that they don't contain any wasps, bees, snakes, lions or, tigers or bears, oh my. Once you are sure you will not disturb the local wildlife, walk through the weeds. Then carefully examine the legs of your pants. Depending on the time of year and the kinds of weeds in your area, there is a very good chance that you will find some burrs stuck to the cloth. Look at them carefully. The burrs that you found are actually seeds, intended to grow new plants. One problem that plants face is that they can't walk around. If a cherry tree could go for a walk, then it could drop its seeds here and there along the way, spreading cherry trees across the country. Since the tree is rooted in one spot, it needs another way to spread its seeds. Try eating a cherry. Eat it carefully, because in the center you will find a large, hard pit. That pit is actually a cherry seed. When you finished eating the cherry, what did you do with the pit? You threw it away, right? Animals do the same thing. A bird could carry the cherry to a nearby fence. After eating the cherry, it drops the pit, planting a new cherry tree. If the bird swallows the pit, it will eventually pass on through the bird and still have a chance to grow into a tree. Some plants have seeds that can only grow when they have passed through a bird. Burrs are another way that plants can spread their seeds. Instead of offering a yummy treat as the bribe for carrying a seed, plants with burrs bother you into planting their seeds. Here in St Augustine, we have a plant called a sandspur. The plant looks like an ordinary clump of grass, but it produces clusters of VERY sharp, thorny seeds. These things really hurt! While walking on the path to the beach, you can see tourists step on one. They yelp, hop on one foot, and say all sorts of naughty things as they pull the thorny seed out of their foot. Then they do something that they really should not. They throw the seed on the ground! They have just planted another sandspur plant! Some burrs just stick to you instead of hurting. If you are lucky enough to have some of these, look at them very closely. You may want to use a magnifying glass or microscope. Look carefully at the hook-like hairs. Do they remind you of anything? Next, look carefully at some Velcro. Wow, it looks the same. It should. Plant burrs gave George de Mestral the idea for Velcro. There are many other ways that plants spread their seeds. Wind is a great way for plants to spread. The next time you blow the seeds from a dandelion, remember that you have just planted quite a few more weeds in your lawn. Plants like Jewelweed have seed pods that build up tension as they ripen. When the seed is ready, the slighted touch causes the seed pod to split apart, throwing seeds in all directions. Some seeds float in water, letting the current move them to new locations. Of all the different ways, I think I like the cherries the best. In fact, I think I will go prepare some cherry seeds right now. Have a wonder-filled week. I got the idea for this experiment while walking the dog. She always seems to pick up some burrs, and as I was picking them out, I realized that I was helping the plants that were causing me problems. To find out, you will need: 1. an area with some weeds 2. long pants 3. some cherries, plums, apples or other fruit with hard seeds First, look carefully at the weeds. Make sure that they don't contain any wasps, bees, snakes, lions or, tigers or bears, oh my. Once you are sure you will not disturb the local wildlife, walk through the weeds. Then carefully examine the legs of your pants. Depending on the time of year and the kinds of weeds in your area, there is a very good chance that you will find some burrs stuck to the cloth. Look at them carefully. The burrs that you found are actually seeds, intended to grow new plants. One problem that plants face is that they can't walk around. If a cherry tree could go for a walk, then it could drop its seeds here and there along the way, spreading cherry trees across the country. Since the tree is rooted in one spot, it needs another way to spread its seeds. Try eating a cherry. Eat it carefully, because in the center you will find a large, hard pit. That pit is actually a cherry seed. When you finished eating the cherry, what did you do with the pit? You threw it away, right? Animals do the same thing. A bird could carry the cherry to a nearby fence. After eating the cherry, it drops the pit, planting a new cherry tree. If the bird swallows the pit, it will eventually pass on through the bird and still have a chance to grow into a tree. Some plants have seeds that can only grow when they have passed through a bird. Burrs are another way that plants can spread their seeds. Instead of offering a yummy treat as the bribe for carrying a seed, plants with burrs bother you into planting their seeds. Here in St Augustine, we have a plant called a sandspur. The plant looks like an ordinary clump of grass, but it produces clusters of VERY sharp, thorny seeds. These things really hurt! While walking on the path to the beach, you can see tourists step on one. They yelp, hop on one foot, and say all sorts of naughty things as they pull the thorny seed out of their foot. Then they do something that they really should not. They throw the seed on the ground! They have just planted another sandspur plant! Some burrs just stick to you instead of hurting. If you are lucky enough to have some of these, look at them very closely. You may want to use a magnifying glass or microscope. Look carefully at the hook-like hairs. Do they remind you of anything? Next, look carefully at some Velcro. Wow, it looks the same. It should. Plant burrs gave George de Mestral the idea for Velcro. There are many other ways that plants spread their seeds. Wind is a great way for plants to spread. The next time you blow the seeds from a dandelion, remember that you have just planted quite a few more weeds in your lawn. Plants like Jewelweed have seed pods that build up tension as they ripen. When the seed is ready, the slighted touch causes the seed pod to split apart, throwing seeds in all directions. Some seeds float in water, letting the current move them to new locations. Of all the different ways, I think I like the cherries the best. In fact, I think I will go prepare some cherry seeds right now. Have a wonder-filled week. tag:odeo.com,2007-12-27,22480711 Thu, 27 Dec 2007 18:42:19 -0800 no Experiment of the Week biology, Science, botany, project, fruit, plants, seed