Cosmos Computed

What exactly is polarized light? You may have heard of it before, or read the name. It sounds cool, so what is it? That is what I will explain in this post. Light is like a wave, or bumpy curve, in many respects. This wave is a sine wave (see my Sine and Cosine post). The wave can oscillate (wobble) in an up-down motion, or a left-right motion; sometimes it does a mixture of both, and wobbles in a circular pattern. Look at the wall, or the floor. There are quadrillions of light waves bouncing off them. Some of the light waves oscillate in an up-down motion, others oscillate in a left-right motion, and others oscillate in a diagonal motion. The different types of waves are all jumbled together. Is it possible to have a bunch of light waves that all wobble the same way? Yes! Light like that even has a name: polarized light . You can buy filters that will polarize light; the filters are called polarizers , or polarized filters . Some sunglasses are made with polarized lense...

Trigonometry is the study of the relationship between the angles and sides of triangles. The two most essential parts of trig are the functions  sine and cosine . Both take an angle, and return a number. The way they work is really quite simple. A diagram showing sine (abbreviated sin) and cosine (cos) To find the sine of the angle θ , draw a circle with radius 1 on a graph, and put the circle's center at the origin of a graph. Find a point on the edge of the circle. The point makes an angle with the center of the circle; make sure that the angle is  θ . Sine of  θ  is the point's y-coordinate. Cosine is the point's x-coordinate. (See the picture to the right.) Sine and cosine are very useful for calculating heights and distances. For example, let's say somebody needs to know the height of a sky scraper, but isn't able to measure it physically with a tape. If he walks a certain distance away from it, and looks at the angle it subtends in the sky, he can us...

The Geminid meteor shower is coming up! At 2:00 AM, on December 14 (that's Thursday night, or Friday morning), you can see anywhere from 100 to 150 meteors per hour - depending on the sky and weather conditions. That's more than 1 meteor per minute! This particular meteor shower comes from a 5.1 km wide asteroid called 3200 Phaethon. Flecks of debris fall off this asteroid in a trail around the sun. These bits are called meteoroids . Every year, in December, Earth passes through this stream of meteoroids; when one of them enters Earth's atmosphere, it burns up and we see a meteor. If the meteor is brighter than Venus, it's called a fireball. Fireballs are much less common than meteors. This year, viewing conditions will be especially good; the peak occurs only 1 day past new moon. If you live in an area with lots of light pollution, you will definitely want to drive into the country. If you think the weather will be bad, go out a day or two before or after the peak. Kee...

You might want to check out my Blue Moon post before you read this one. It was late at night. The full moon lay high in the starry sky. Suddenly, everything started getting brighter and brighter, until the moon was as bright as the sun, and everything looked the way it does in the middle of the day - except for the glaring light pollution and the burning stars. Astounded, I pulled out a camera and snapped the photo above, and some others you can see in my Blue Moon post. About an hour later, everything went back to normal. Does that sound like a true story? Well, it isn't; that night was just like any other. To take the photos, I used a trick that I will explain in this post. When a digital camera takes a photo, this is what happens: a shutter on the front opens up, and a lens focuses light onto a tiny charge-coupled device (CCD) inside the camera. When the light hits the CCD, a small electric charge becomes present. As more and more light hits that part of the CCD, the charge ge...

These are some of my pictures from October. Some may have been trimmed, but most were not. To see a larger view, click on the image. First are some pictures of black-billed magpies, one of the most common fall/winter birds where I live: And here are some contrails. Contrails are the clouds which airplanes leave behind them. Contrails The next 3 pictures were taken through some stacked loupes my mom gave me. See if you can figure out what they are. Now here's a picture of the moon. It was in its waxing crescent phase; "waxing" means "getting larger", and you probably know what "crescent" means. This is a picture of one of our first snowfalls. Now a kid in a costume. Now here are some eggs. You might recognize them from a previous post.

Lately I've been eating much larger breakfasts than I used to eat. Almost every morning, I eat 6 to 7 eggs plus something good like a glass of juice or a fried sliced potato, or sometimes a bowl of cereal. This is very strange compared to what I used to eat: 2 bowls of cereal, or some pancakes. What happened? Well, at one point my dad found some bowls of wasted cereal on the table. They weren't mine, in case you're wondering. So he decided to just stop buying cereal; if people waste it, why bother? Now that my main breakfast food was gone, I had to find something else to eat. I had tried oatmeal before, and hadn't liked it a lot. I tried it again; still the same problem (as a side note, let me say that I never waste food if I have the choice). Eventually, I decided to try eggs. A plate of eggs. I ate them all. You may be wondering why I never tried that before, and the reason is that I don't like eggs without toast; without toast, what do you do with all that runny ...

Yesterday was Halloween. Some people I know don't do anything on Halloween. I'm not one of them, and never have been; I've gone trick-or-treating every year since I was about 2 or 3. When I first started, I didn't stay out very long, and at least one of my parents stayed with me at all times. Yesterday I stayed out for about 2 ½  hours with some siblings and a couple of friends, and would have stayed longer if I was allowed; the candy I get then is pretty much all of the candy I get for the next year. And it really does last that long. Even now, I still have a few pieces of candy left from last year! You might be able to guess that I'm proud of my self-control when it comes to Halloween candy. My other siblings finished off their candy many months ago. The main idea for trick-or-treating is to dress up as something cool. This year I was planning on being a burglar, since I couldn't think of much else. My sister told me that she was dressing up as Buttercup from ...