Today on Science Mysteries…Explained!, we’re going to ask that age-old science question that thousands of kids (and a few adults) are asking just about now: “Why do leaves change color in the fall?” Some trees and bushes have leaves that change color each autumn. In fact, in some regions of the world, forests look like someone took bright crayons and scribbled all over them in fall! Why does this happen? It’s all thanks to a special molecule called chlorophyll. Chlorophyll is a unique molecule called a pigment. A pigment is able to absorb certain wavelengths of sunlight. Chlorophyll absorbs all colors of light (white light is made up of all the different colors you see in a rainbow) except green. This means that it reflects green light. As a result, when we look at most plants, they appear green.

Chlorophyll’s main job is to help plants harness the energy in sunlight to make food. In the autumn, when there are fewer hours of sunlight, some trees, known as deciduous trees (deciduous means that their leaves fall in the autumn), begin to make less chlorophyll. As a result, their leaves no longer reflect green light as they did in the spring and summer. When this happens, leaves reveal some of the other pigments that were hidden before. These hidden pigments are different colors, such as yellow, orange, red, and purple. They can’t be seen in the spring and summer because the leaves on the trees are green thanks to chlorophyll. But when there is less chlorophyll in the fall, they really put on a show.

If the last blog post on feathered velociraptors caught your interest, you might be interested in the question we’re asking today. It’s a question that is often on the mind of palaeontologists (scientists who study dinosaurs and other extinct creatures): Did feathered dinosaurs glide or did they actually fly like birds do, by flapping their wings?  Of course, we’re not talking about velociraptors and other dinosaurs that just had a few feathers here. We’re talking about small dinosaurs a few feet long that were covered in feathers and soared through the air…at least so we think.

Luckily, new research may have an answer to the flying dinosaur question. Scientists have new idea about how a certain dinosaur used its wings. This dinosaur is called Microraptor mui. It was about 3 feet in length and lived in China millions of years ago. But it left its fossilized feathers and bones behind. Fast forward to the present… Scientists in the 21st century have looked at the fossils. And they’ve noticed that the tiny dinosaur had a second set of “wings” that consisted of long feathers on their legs and feet. This would have made it difficult for them to get around on the ground (Colonel Sanders would have caught them pretty quickly)! But researchers think that they stayed in the trees all the time. When they wanted to get to another tree, they dropped their legs and used them like a lower set of wings that helped them glide from tree to tree. Have you ever seen an old-fashioned airplane or stunt airplane with two sets of wings, one upper and one lower? That’s pretty much what this dinosaur looked like when it glided.

Have you watched Jurassic park at least a dozen times? Do you think that you know everything there is to know about velociraptor dinosaurs? If so, you may be surprised at this new finding from a fossil found in Asia’s Gobi Desert. When scientists took a closer look at the bones of this predator dinosaur, they found small raised bumps on some of them. What were these bumps for? They seemed very familiar. In fact, they are found on the bones of many modern relatives of dinosaurs—birds! The bumps, also known as quill bumps, occurs where feathers are connected to the bone. This means that the velociraptors the scientists were studying had feathers!

Were velociraptors covered with feathers? Probably not. The bones with the quill bumps on them were found in the arms of the dinosaurs. They had about 14 large feathers on the forward part of each arm. But this is the first time evidence of feathers has been found on a dinosaur this big. Velociraptors are about 1.5 meters long. Other dinosaurs with feathers were way smaller in size!

Did they use the feathers to fly? Not likely, because velociraptors were just too heavy for that. But scientists think the feathers may still have been useful. They may have helped the dinosaurs jump higher. Or they could have been protective. The dinosaurs may have used them to hide their eggs from predators or keep them cool in the hot sun. Who knew you could learn so much from an old set of bumpy bones?

Does this sound like you? You’d rather snuggle in your soft warm bed until noon and hate waking up in the morning. Your brain can’t even figure out where your socks go until the recess bell rings. And your teacher doesn’t bother asking to answer a question (at least correctly) until after lunch. If this sounds way too familiar, you’re not alone. Scientists have discovered that another creature detests morning just as much as school kids do! Which ones? Would you believe cockroaches! Yikes!!

Yup, it’s creepy, it’s crawly, but it’s true. Cockroaches are slow starters that can’t get their brains into gear until later in the day. When scientists tested cockroaches’ ability to catch on to a new task, they were pretty sorry specimens in the morning. But they were as bright as a button later in the day. Scientists have never seen a creature that gets smarter as the day goes on before (I guess they’ve never studied teenagers!). It turns out that these critters just can’t keep a thought in their head in the morning! What gives? Scientists have absolutely no idea whatsoever! They are stumped.

How about some more crazy health news in today’s blog? You’ve probably heard the saying that an apple a day keeps the doctor away. (Your parents might use it to get you to eat fruit, if you don’t like it.) But did you know that organic apples might actually be better for you than apples grown with pesticides?  To find out more about this, we need to go right to the core of the issue… the apple core that is! That’s where codling moth caterpillars like to hang out. These little critters are actually pests in the eyes of apple orchard farmers. Over the years, farmers have kept their number in check by exposing them to a virus that specifically harms this type of worm.

And now to the core of the story… It turns out that the virus affects worms that munch on organic apples much less than worms that eat apples grown with pesticides. How come? Scientists think that eating organic apples makes the little fellows healthier. Why this is happening is still a mystery to scientists. Maybe you have a few ideas of your own?

If you love chocolate, you’re going to love this blog post! According to a new research study, chocolate (and the more cocoa in it the better), can actually help make some sick people feel a whole lot better, often in cases where medication has failed. Wow! I always knew chocolate was pretty powerful stuff, but this is pretty cool! How does it work? It turns out that there are chemicals in chocolate known as phenols. Phenols may have an effect on a special substance in our brains known as serotonin. Serotonin is low in people who have a disabling disease called chronic fatigue syndrome. People with chronic fatigue syndrome are tired all the time. But taking 45 g of dark chocolate a day actually helped them feel a lot better!

So how much chocolate is 45 g? It is about half a regular sized tablet chocolate bar. And even though chocolate is rich in fat, the good news is that no one in the study gained weight. Weighing too much is another health risk. And scientists wouldn’t want to treat a disease with something that harms your body in another way. And of course, there is another benefit—chocolate tastes great! I bet a lot of you chocolate fans out there could have told the researchers that chocolate makes you feel great, even without doing a study! Wouldn’t it be great if one day your mom gave you Smarties™ to cure a sniffling nose? Who “nose?” Bring on some more delicious medication!

Well, if that last post on farting farm animals didn’t give you a large enough dose of gross, you really need to read today’s blog post! Today we’re once again visiting a few rear ends, but instead of cows and sheep we’re going to get the scoop (or rather the “poop”) on panda dung (the scientific word for poop)! Yes, it’s time again for your favourite blog topic “Science mysteries… explained!!!”  And today we’re going to solve that age-old science mystery… What can you make out of panda poop? Now don’t tell me you aren’t curious. Maybe the question hasn’t been burning in your mind, but the people who run zoos in China and other parts of Asia have given it a lot of thought—after all, they have a lot of panda poop to deal with every day!

What did they come up with? It turns out that you can really make an amazing amount of things out of those stinky brown blobs—and they are all odor-free! Everything from bookmarks to panda poop photo frames. Of course, they don’t look like panda poop in the end. That’s because the dung goes through a long process where the undigested bamboo leaves found in it (pandas eat only the leaves of bamboo plants, nothing else!) are made into paper, just like we make paper out of wood. The dung is sterilized at super-high temperatures when it is cleaned. Next it is mashed to a pulp and dried to make paper. The paper is then used to make objects that the zoos sell as souvenirs for a nice amount of cash. After all, there’s nothing like a nice pad of panda poop paper!

Last week we looked at a pretty cool, high-tech way in which we might be able to fight one of the affects of climate change. So just to be different (we like to do that here), on this post, we’re, going low-tech. Yup, you heard it right, low-tech solutions against the mighty force of the global climate. And just how low are we willing to go? Well, we’re talking down in the dirt low here, and it’s not just us. The movers and shakers in the field of climate change science have been going low-tech as well. Will low-tech solutions stand a chance? Scientists seem to think so. And to put their test tubes where their mouths are, they’ve been conducting experiments on ways to reduce the production of greenhouse gases (gases that trap heat in the atmosphere and cause global warming) in one of the most low-tech places you could imagine—in a field of cows!

What do cows have to do with climate change you ask? A lot, it turns out. Cows and certain other grass-eating farm animals, such as sheep, produce a special type of gas called methane. Methane is a powerful greenhouse gas. It heats up the planet 21 times better than carbon dioxide gas. How do cows and sheep emit methane? Well…let’s just say that there’s a whole lot of fartin’ going on! So much farting in fact that scientists estimate that these farm critters produce about 16% of the world’s methane.

To find a solution to this stinker of a problem, scientists have turned to another low-tech solution. One that our ancestors have used in the past to prevent everything from the common cold to unsuspected vampire attacks. Yup, we’re talking about garlic. This stinky plant has been used as human medicine throughout history, and now it might just cure a serious global problem as well. How does it work? Scientists have found that when garlic is added to cow and sheep fodder (food), the bacteria (single celled creatures that can only be seen with a microscope) that produce methane gas are killed. The end result is one sweet smelling cow and one happy planet.

And remember, you got it straight from the cow’s rear end!

Well, it’s autumn again (and that means starting your science fair project!). Time to mess up the giant pile of leaves that your neighbor just spent an hour raking up! (But don’t say you heard it here!) It’s also time for one of the most amazing feats in the natural world—the migration of birds. Have you ever wondered how migratory birds find their way from the northern latitudes, such as Canada, the northern US, Europe and Asia, to the warm tropical regions where they spend the winter months??

Well, it looks like scientists may have found the answer (no surprise here!). Would you believe they use road signs? Not ordinary road sign of course, but it seems that migratory birds do have a special type of vision that allows them to see the lines created by the Earth’s magnetic field. They follow these markers to get to their destination. This may sound pretty strange to you, but the process works a lot like human vision. When humans see an object, they are actually seeing light that is reflected from the object. And what is light? Light is radiation, a unique combination of a particle and a wave, which special sensors in our eyes pick up. Once they sense the radiation, a signal is sent to the brain, which interprets it as an object. A similar thing happens when birds “see” magnetic radiation. Sensors pick up the radiation and send a signal to the bird’s brain, which receives a sort of visual compass reading that directs it where to fly!

Wow, get set for some really freaky frogs in today’s blog post! The latest breaking news is that a team of scientists in Japan have bred a see-through frog—no kidding. Why see-through? It’s the newest way to make high school science labs a little more frog-friendly! Each year millions of science students around the world dissect (cut apart) frogs to get a closer look at their organs, such as their heart, lungs, and guts. But the problem is that they have to cut up dead frogs to see these structures. Enter Japanese scientist Masayuki Sumida and his see-through frogs! This frog’s skin is so pale that students are able to see right through it and observe its organs while the frog is alive! They get to see its heart pumping and the happy frog gets to live to see another dawn! Everyone is happy, including Dr. Sumida, who bred this new type of frog for exactly that—to create humane (frog-friendly) science classrooms. Two giant thumbs up for Dr. Sumida! Apparently, students will get to observe these frogs over their entire lifetime. This means they will see some amazing changes in a frog’s organs as it grows from a tadpole to a full-grown frog. If they are lucky, they can even watch their see-through frog laying eggs! Now that’s something to “croak” about!

To see a video of these frogs in action, go to http://news.bbc.co.uk/1/hi/sci/tech/default.stm and type “see-through frog” in the search box. Watch the frog’s organs in action right on your computer screen!