Cosmos Computed

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

In this post, I'll tell you about a really cool new site I found: Khan Academy. Khan Academy is basically a bunch of free tutorials for school subjects like mathematics, history, science, and just about anything else. And not only that, but they also have a special practice page that offers exercises, and when you complete enough of them you get points. And here's one of my favorite things about it: they have a special section just for computer science, so I can write programs (mostly video games), and everybody else can see and play them. So far I've only written one program, but it's pretty good for my first (even though it's not finished yet). But one of the coolest things about that programming feature is that you can embed the program on a web page: Super Ball Another nice thing is the badges you get for accomplishing certain things. There are 6 types: meteorite, moon, earth, sun, black hole, and challenge. The easiest to get are the meteorites, and the hardest

Blue moon sounds like a moon that's blue. And it can mean that, sometimes. But that's not the real definition. By the calendar, a blue moon is the second full moon of a month . The original definition (a seasonal blue moon) is the 3rd full moon in a season that has 4 full moons . Either way, a blue moon occurs approximately every 2.68 years. The full moon of August 31st, 2012 was a blue moon by the calendar. I had to see it, because I won't see another for at least 2.68 years (I'll see a seasonal blue moon in August 2013, though). So I got a camera and a tripod and headed outside. It was warm, and everything cast shadows from the moon's light. The first thing I did was to set up my camera and tripod and point it at my house. After changing the camera's settings, I took a picture. Here's what I got: Moonlit House Pleased with the results, I took some more pictures, a few of which you can see in my last post. I didn't actually get a picture of the moon f

Here are some pictures I took. See if you can guess some things about the photos: Approximately what time of day the photo was taken at, or if it's computer-generated Which parts of the photo were computer-generated, if any The season (for outdoor photos) To view the images better, click on one. I'll give answers later. House Crayons Calendar Blue Moon Weeds and Grass

Diving can be done well or poorly, depending on how good the diver is. Sometimes, beginning divers will do "belly flops", smacking the water horizontally instead of cutting into it like a needle. Whether a dive is a good one usually depends on whether the diver went straight into the water or not. Experienced divers can do this without thinking much about it, as if it were like walking; beginners, however, have a lot more trouble. In time, people get used to diving; machines, however, can't learn, and are always just as clumsy. If the machine contained a computer, it would need a computer program to help it dive. The program would need to use a math formula. Here's what we'll start out with: v 1 = v 2 tan θ , where v 1 and v 2 represent forward and downward velocities, and θ is the vertical angle in degrees.   Here's how it works: the forward and downward velocities of a good dive have the same ratio as the sine and cosine of the vertical angle of the di

A couple of pieces of good news: First, in this post will be the answer to the problem I gave called Flipping Quarters ; and second, I'll even work through the solution! We have to figure out the average amount of money that the man pays you, minus $5. To start out, let's forget about the money and look at the actual coin flipping. Since it's about as likely for the coin to give tails as it is to give heads, you would get heads 50% of the time. So on your 1st flip, there's a 50% chance you'll get heads - a 50% chance that you'll have to stop. What is the chance that you'll have to stop immediately after the 2nd flip? There's a 50% chance that you will actually get to the 2nd flip, and a 50% chance that you'll flip heads on it. Multiply those numbers, and you get 25%. Look at the diagram to the right if you don't understand. Now for the 3rd flip: there's a 25% chance there will be one (because you got tails on the 2nd flip), and a 50% chance y

In a couple of my posts, you may notice some computer generated images or animations. They were created with Blender. In this post, I'll explain how I got it and started using it. A long time ago, I wrote a BASIC program that drew a circle; the user would give the program a number, and it would draw a circle that size. There was a problem, though: the circle had a lot of holes in it. I solved the problem by filling the circle, but that was like cheating. I told my dad about the problem, and he showed me a book about graphics. I looked through the book, but didn't find anything about my problem. I did find a section with nice, colorful computer-generated images, however - and some were so good they looked like photos! At one point, there was a series showing the construction of a photo-realistic image of a room, starting with the edges, then moving on to the surfaces, texturing, lighting, etc. Here's a similar series I made using Blender (but not photo-realistic): Edges Su

Here's an interesting puzzle involving chance: A man in a park asks you to play a game with him. It's a form of gambling. To play, you must pay the man $5, then flip a coin repeatedly until you get heads. As soon as you get heads, you stop flipping. If you only flipped the quarter once, he'll give you $1. If you flipped it twice, you get $2. Three times, $4. Four times, $8. Each extra flip gets you twice as much money, so the longer it takes before you get tails, the more money you get. Should you play, if you have a lot of time and the man will play as many games as you want? How much money, on average, would you gain (subtracting the $5 fee)? I will give the solution in a later post .

Cumulus is the Latin word for pile or heap , and cumulus clouds certainly fit their name! They look like fluffy mounds of whipped cream floating in the sky, and often have a shape similar to that of a cauliflower.  Cumulus clouds form when relatively warm, moist air rises and cools below the dew point. The moisture in it then condenses into tiny water droplets, which form the cloud. The relative humidity (how "full" the air is with water) helps determine the height at which the moisture condenses at, which is the base of the cloud. In this little video I made, you can see how the clouds form, with the moist air appearing a light mist rising out of the ground. The moist air is not visible in reality, but I added it to help illustrate the idea: A cumulus cloud constantly undergoes change, as long as moist air continues to rise under it. The water droplets at the edge of the cloud usually evaporate, so the cloud loses water as it gains it. In a time-lapse, the clouds appear t

Few people watch birds very closely nowadays, or go to any lengths to identify them. That's their loss - bird-watching is fun, educational, and a way to pass the time when you're bored. After bird-watching for a year or two, you can identify birds a lot more easily, and you aren't as clueless when people ask, "What kind of bird is that at your feeder?" So what do you need to bird-watch? Binoculars are essential; without them, many small markings can be indistinguishable. A field guide is also important. David Allen Sibley's guides are probably best, but anything will work as long as it covers your area thoroughly enough. And that's it. There are other little things that may be helpful, like a camera or a notebook, but these are all you really need. If you already know a little about bird identification, then you're ready to start looking for birds to identify. But if you're a beginner, you may need a little more help. You might see a large black a