Why Do You Get Tired After Thanksgiving Dinner?

Ever feel really sleepy after Thanksgiving dinner? Ever watch your grandfather fall fast asleep after eating his Thanksgiving meal? You are not alone. Many people hit the hay after enjoying their Thanksgiving feast featuring everyone's favorite bird - the turkey. Some think that the turkey makes them tired. Is this true?

People think turkey puts them to sleep because it is made up of L-tryptophan. But what is L-tryptophan? L-tryptophan is an amino acid. An amino acid helps to build proteins. Proteins are very important to your body. Along with making up your muscles so you can move, proteins also control the billions of chemical reactions that happen in your cells every day. If these reactions did not take place, you would not be able to make stomach acid to digest your food, produce sweat to cool yourself off in the summer, get oxygen and nutrients from your blood to your cells, fight off infections or do pretty much everything your body needs to do to stay alive.

Proteins are made up of various amino acids, not just L-tryptophan. Humans need to eat nine "essential" amino acids to survive. L-tryptophan is one of these nine. It is a normal and important part of everyone's diet. L-tryptophan is also natural sedative or, in other words, a compound that relaxes people and makes them sleepy. L-tryptophan also helps to make serotonin--a normal chemical in the brain that is also a sedative. Some people actually take L-tryptophan to help them fall asleep. But, in large amounts, it is not healthy and could cause serious problems such as death. As a result, the Food and Drug Administration, the government agency that decides which foods and drugs can be legally sold in the United States, banned it from being sold in this country.

Even though L-tryptophan can help you fall asleep, it is unlikely that the amount in your Thanksgiving turkey is putting you to sleep. This is because L-tryptophan only affects the brain if your stomach is empty and there are no proteins present. Do you plan on eating only turkey for Thanksgiving? What about those delicious food items on your plate such as candy yams and cranberry sauce? And, who can forget about that pumpkin pie? Also, turkey is made up of many proteins, so L-tryptophan would not be alone in your stomach even if you did pass up all the other delicious dishes.

As you can see, if you are tired after turkey, it is probably not the L-tryptophan in your turkey that is making you fall asleep. You are probably just tired from helping your parents cook that great, big meal or from working up an appetite while playing football outside with all your cousins or from simply overeating. Overeating---not just turkey, but mashed potatoes, cranberries, yams, peas, carrots, bread, pies, and whipped cream---demands a lot of blood to be pulled towards your digestive system to help break down all that food. This blood is pulled away from your brain. Your brain constantly needs blood for you to think and be alert. Losing even small amounts can cause you to feel tired. So, if you want to stay awake for desert or to watch the end of The Sound of Music or to see your neighbors start to put up their Christmas decorations, you should probably take your time and enjoy your meal. Don't fill up! And, after that delicious dinner, take a walk or help wash the dishes.

Little Lion Experiment:

Corn was a stable food item for the Indians because it was easy to grow and very nutritious. Try to grow your own!

Materials:

• Kernels of popcorn
• Ziploc bag
• Dirt
• Water

Procedure:

Place a couple handfuls of dirt into your Ziploc bag; add a little water and a few kernels of popcorn. Then, seal the bag and place it in a sunny window. Observe your corn grow. In about a week, your corn should be sprouting

For the advanced scientist, you can make a couple bags of corn and test the effects of different amounts of sunlight, water and air. Be sure to record how much or how little you provided your kernels.

How Should You Clean Earwax?

Have you ever wondered where earwax comes from? Your ear, of course! But where in your ear is earwax made? Earwax, which scientists call cerumen (pronounced suh-ROO-muhn), is made from special glands in your outer ear canal. These glands produce the gloppy substance that we call earwax. The outer ear canal is a tube between that flap of skin on each side of your head that scientists call the auricle, what most people think of as your ears, and your eardrums.

So what does earwax do, exactly? Well, your eardrum is a very sensitive membrane. It's only a few cell layers thick, so it is very important that it stays clean. Earwax protects the eardrum from dust and dirt particles that may irritate it. Dirt particles entering the ear get trapped in the gooey wax and are eventually pushed out of the ear naturally. In a healthy ear, earwax is pushed to the outside of the ear where it eventually flakes off, carrying whatever dirt and grime it has collected with it. Earwax also traps and prevents bacteria from growing in the ear canal, helping to prevent ear infections.

So how do you clean the earwax from inside your ear? You don't! Never stick anything smaller than your elbow in your ear canal! Earwax helps to prevent harmful substances like dirt and bacteria from reaching your eardrum. It also helps to keep your outer ear canal moist. Ear canals that do not have enough wax tend to become itchy. Cotton swabs should NEVER be stuck inside your ear, because they can damage the sensitive skin of your ear canal, causing it to bleed, and can even hurt your eardrum. Sometimes, using things such as cotton swabs or pencils will push earwax back into the ear canal and up against the eardrum. This is BAD! If this happens, it may be difficult to hear very well. Although there are some over-the-counter remedies for compacted earwax, should this happen to you, you should have your parents call your doctor and ask what the best treatment is. A healthy ear canal will naturally push out old wax, keeping itself clean.

So how do you clean the earwax from outside your ear? All you really need to do is wash your hair to clean your ears. The soap and lather from washing your hair will get into the folds of the auricle, the part of the ear you can see, and help wash away old, flaky earwax. You can also put a cloth over your finger, and wipe the folds of the auricle, but do NOT stick your finger into the ear canal.

Little Lions Experiment:

Materials:

• 2 old paper towel tubes (outer ear canal)
• 2 sheets of facial tissue (eardrum)
• petroleum jelly (earwax)
• dust, dirt or lint (grime)

Steps

1. Tape a sheet of facial tissue to one end of the paper towel tubes. Make sure one end of each tube is completely covered by one layer of tissue.
2. Spread petroleum jelly inside one of the tubes. Leave the other tube without any petroleum jelly. Only spread the jelly in the upper half. Do not let it go too far down the tube. Do not let it touch the facial tissue.
3. Set the tubes beside each other, and prop up the open ends about 30 degrees.
4. Throw the dust towards the tubes.
5. Carefully remove the tissue paper. Compare how dirty the tissue paper got for the tube with the jelly and without the jelly. Did the earwax prevent the grime from hitting the eardrum?

Why Don't Animals Need Glasses?

Roughly, forty percent of people wear contacts or glasses. Some scientists think that the cause is genetic and some think is because of our surroundings.

Scientists have been able to show that people who look out over long distances, like sailors, often do not have problems with short-sightedness or are not myopic (MY-OP-ICK). People such as tailors who have to focus their eyes close to their face often are myopic. It seems that muscles on the side of the eye will correct the eye and help it to see more clearly. If you were to travel to primitive parts of the world, you would see people who have excellent vision without the help of glasses.

Monkeys that have been taken from the wild and held in captivity have been shown to only focus on this close to them. They have become unable to focus far away. Scientists gave chickens glasses and showed that they could cause the chickens to be nearsighted (see things only close to their face, or beaks) for a short time. Imagine a chicken with glasses!

Another theory as to why animals are able to see well is because those that cannot do not live for very long. This is the survival of the fittest theory. That animals that are the strongest will survive the longest and make more animals that are the strongest.

Among domesticated animals, or animals taken from the wild, like cats and dogs, eye problems are likely as the animal gets older. Older domestic animals and humans typically get what are called cataracts (CAT-TER-ACTS). Cataracts are when the front part of the eye becomes cloudy and hard to see through. Have you ever seen an old dog with blue-grey hazy eyes? This is probably because of cataracts.

Little Lion Experiment:

Do you or people in your family wear glasses? Try on some of your family members' glasses and see if you can figure out if they are near- or far-sighted. Do not keep the glasses on too long; they might give you a headache!

Do you see a pattern in the age of the person wearing the glasses and the strength of the glasses? Do older people in the house have stronger glasses than younger people?

A good scientist always looks for trends in the results from their experiments.

Perform a search on the Web for information about the eye and vision problems. Pages like http://www.google.com or http://www.yahoo.com are good search engines. If you just search on eyes, you will get a lot of information.

How Does A Pencil Eraser Work?

The pencil eraser works based on the friction developed between the eraser and the paper. Friction is what causes your hands to heat up when you rub them together. When you rub two objects the roughness of their surfaces contact each other and rub against each other causing friction. A pencil is made of graphite. Graphite is a mineral composed of an element called carbon and is black in color. A pencil mark consists of graphite particles that peel off from the pencil point by the paper. These particles, which have an angular, gritty look under the microscope, are commonly used in hard black (HB) pencils, typically between 2 and 10 micrometres in diameter. This is about 6 times smaller than the thickness of the human hair!

When the pencil is used on a sheet of paper, the graphite particles lie slightly below the surface of the paper, interlocked between its fibers. A single rub using an eraser sufficiently soft to reach between the fibers will pick up most of them. Looking at the eraser you can see undamaged graphite piece sticking to the surface. An effective erasing material scratches the paper surface, producing the familiar small spindles of rubber or eraser material, which wrap up the graphite particles. When you look at these under an optical microscope at 200 times magnification (200x), these look like roly-poly puddings studded with graphite raisins.

Little Lion Experiment:

Erasers come in a variety of colors: white, pink and gray are some of them. Sometimes the color difference is because of a dye or because the eraser is made of a different type of rubber. Go around you house and see how many types of different erasers and pencil leads you have; number two and number three pencils are different types of leads. Remember the bright-colored erasers, like purple and yellow, are usually white erasers in disguise! If someone in your home has a mechanical pencil, you can purchase different types of lead, like HB or soft, they might have different leads you can use. You can also use erasable pen as a lead type. See which one of these works best with different types of pencils and ink. Can you erase the ink with a pink or white eraser? Is there one eraser that works for all lead types? Knowing what you know about how erasers work, why do you think certain erasers do not work with other types of pencil lead and ink?

Thinking about experiments, scientists look at the different things or factors in the experiment called variables. The variables you have in this experiment are erasers and lead types, assuming you always use the same type of paper. A scientist is always concerned about the number of variables in there experiments because it tells them how many experimental runs they need to do. An experiment run would be a single type of eraser against a single type of lead. The total number of experimental runs you would do in your experiment are the number of erasers times the number of leads. By limiting your variables you limit your number of experimental runs, but you don't want to limit your variables too much otherwise your experiment will not be conclusive or lead to a correct answer that may be misleading. For example, if you use all the lead and eraser types in your house, you can say that you have a conclusive study of the erasers and leads in your house. If you just look at the erasers and leads in your room, you could not say that you know about all the erasers and leads in your house, just about the ones in your room. Sometimes scientists limit there variables, like for instances just the erasers in just your bedroom, and then predict from those experiments to say how the erasers in the house would perform. Not all predictions are good, but sometimes it is the best a scientist can do.

How Do Chicken And Turkey Have Dark And White Meat?

Ever wonder why turkey legs at Thanksgiving have dark meat, while the breast meat is white? The simple answer is because dark meat has more blood vessels giving food and oxygen to those areas than white meat does. But there is much more to the story. Both white and dark meat are skeletal muscles--the kind of muscles that help you move. Muscles contract or shorten, and relax or get longer in order to help you move. The meats are different kinds of skeletal muscles, leading to their different colors. There are three main groups of skeletal muscles: fast twitch glycolytic (GLY-CO-LIT-IC), fast twitch oxidative (OX-A-DATE-IVE) and slow twitch.

What do these words really mean? Well, the muscle groups are named for how they work. The fast twitch glycolytic muscles are powerful muscles that contract or work quickly, but they tire out quickly too. Sprinters who run short distances have trained their legs to use many of these quick working muscles. Muscles that tire out quickly would not be much use to marathon runners who need lots of energy for longperiods of time. Marathon runners have more of the fast twitch oxidative muscles. These muscles also contract or work quickly, but tire out slowly. The reason they do not tire out as quickly as the fast twitch glycolytic muscles is that they have large numbers of factories producing energy especially for them. These energy factories are called mitochondria (MI-TO-CON-DRI-A) and they make energy for cells.

So we have muscles that contract quickly, but tire quickly and muscles that do not tire quickly but use up a lot of energy. What do we do when we need a muscle to contract or work all the time without using up all of our energy? We do not want to be walking around as if we just ran a marathon all the time! Imagine how tired we would be! This is why we have the slow twitch muscles. The slow twitch muscles are like the ones in our back. They are always contracted so we can sit up straight in our chairs. These muscles contain lots of blood vessels so that they can always get food and do not have to produce lots of their own energy with the help of mitochondria. Our body needs all three types of muscles to work properly.

But what does this have to do with chicken and turkey? What type of muscles do you think make up light and dark meat? Let's think about here the dark meat is on a bird. It is found in the thighs and drumsticks. Chickens and turkeys are always on their feet and they do not need to move quickly. Dark meat is therefore a slow twitch muscle. What about white meat? Birds fly rather then walk to get away from something. So it would make sense that they would have fast twitch muscles to help them fly. That is why you find white meat in the breast of a bird. Although chickens cannot fly like turkeys can, they are relatives of birds that can fly and that is why they still have white meat or fast twitch muscle that move their wings.

Little Lion Experiment:

Can you identify where all the different types of muscles in your body are found? Run a sprint down your block and see which muscles you use. Run a around your block a couple of times and try to figure out which muscles you use. Those are your fast twitch muscles. Think about what muscles would be your slow twitch muscles.

Next time your mom or dad has a whole chicken or turkey for dinner ask them if you can identify the different types of muscles while they cut it up. Let your parents handle the knife to cut up the poultry and always wash your hands after handling raw poultry.

What is a Nerve?

A nerve is a cell that is specialized for sending and receiving information. Nerves make up the part of your body that tells your brain what your body is doing, called the peripheral nervous system. Your muscles, your stomach, and even your heart would not function if a nerve didn't send it directions from your brain.

Nerves carry signals like wires carry electricity. The long nerves in your body are like wires and the current would be the signals carried in the nerved. Charged atoms called ions carry nerve signals. The ions move in an out of the nerve cells in a wave-like manner down the nerve. This causes a charge to move down the nerve, this is how a nerve signal is carried. The longest nerve is the body is called the sciatic (si-at-tik) nerve and it is in your leg.

The sciatic nerve is a single cell that begins in your lower back by your spine and runs to the heel of your foot! Some nerves only send instructions from your brain to body parts; other nerves are there to report back to the brain on what is happening to your body. A nerve can actually sense changes in temperature, pressure, pain, or light, if the nerve has the right molecules. That's one exciting area of neuroscience (the study of brain stuff): neuroscientists are trying to figure out what types of molecules are found in each different nerve in your body. If you know what molecules are there, then you have a pretty good idea of what each nerve does.

When nerves are in your brain or spinal cord, we call them neurons instead. These neurons are part of the central nervous system. Neurons are a bit more complicated because instead of just sending information from one place to another, like a nerve, each neuron makes thousands of connections to other neurons. This means that the information can be sent backwards, forwards, sideways, even back in circles inside your head. We think that thinking has a lot to do with the complex pattern of information flowing in your brain. And when you think that these patterns in your brain are a million times more complex than the circuitry of the fastest supercomputer, your brain might just fry trying to comprehend its own complexity.

Consider this. Look up at the sky tonight. Try to count all the stars you can see without counting the same one twice. Now, imagine that each of these stars has nine planets like our solar system, and that each planet has nine moons orbiting it. Now imagine if you could draw lines connecting every moon on every planet to every other moon, creating some sort of a web across the sky. This "web" would look a little like the connections between all the neurons inside your brain.

However, your brain is even more complex than that! Your brain actually contains 10,000,000,000 connections between all the neurons, which is a network so complex, you would have to connect all the stars in the galaxy, including all those you can't see when you look up at the sky, to paint a picture like the complex web inside your head.

Why Are The Basic Colors Different In Paint And Televisions?

The reason why this phenomenon occurs is because rules in mixing paints, inks, and dyes are not the same as those in mixing light. When a painter looks at their palette they can create any color with the three primary pigments: magenta, cyan, and yellow. It is not the same for a projection television. Colors such red, blue and green (called primary colors) are used to create all of the colors.

When the three primary colors of light are mixed, the intensities of the colored light are added. An example of this is where primary color light overlaps. When red light is added to green light, yellow light is formed. All colors can be made by the addition of different lights of the three primary colors. For example, red is 100% of red light and red light only. Blended colors like orange are 1 part green and 2 parts red light. Some color mixing is very complicated, like for instances gray is 3 parts red, 3 parts green and 1 part blue. The equal mixture of all three primary colors forms white light.

Our eyes are like television, in that they mix the primary colors of light to form an image. The human eye consists of two types of light receptors, rods and cones. Rods are used for light at low levels, like when you are in the dark. Rods in your eyes tell your brain to see things in black and white, so they perceive how much dim or intense the image is. Cones are what we use to see color. There are three types of cones: cones sensitive to red, blue and green. Based on how much each type of cone is stimulated due to the specific light, we perceive the color of light. For example if both red and green cones are stimulated, then we perceive yellow light. If only green cones are stimulated, we perceive it as green light. These three types of cones generate color vision.

Whereas primary colors are mixed in an additive manner, primary pigments are mixed in a subtractive manner. The primary pigments for mixing dyes used in coloring, photography, and printing are: magenta (light purplish pink), cyan (light blue) and yellow. The dyes of inks absorb certain colors. Any color that is not absorbed (subtracted) is the hue that we see. These dyes act as filters that subtract one or more colors. By varying the proportion of the colors in a mixture, a full range of colors can be produced. For example, the color yellow absorbs blue and reflects red and green. Magenta absorbs green and reflects red and blue. So, the mixture of yellow and magenta equals red (white minus blue minus green equals red). The mixture of all primary pigments is black, all light being absorbed.

In printing, the primary pigments are layered. A white layer is laid down first, followed by a yellow, magenta and cyan layer. Each pigment layer is carefully laid out to create a final image with the desired colors