Cosmos Computed

The actual sun appeared bright red, but my camera picked up some invisible radiation as violet. This photo was not enhanced. Last year was very dry. Wildfires raged through the state, and a firework ban on Independence Day made everybody even more sorry about the lack of water. I think this summer is turning out to be a repeat. So far we've had 3 historically significant fires: the  Black Forest Fire , which burned 14,280 acres and was the most destructive ever recorded in Colorado (in terms of property damage); the Royal Gorge Fire , which burned 3,800 acres and jumped the Royal Gorge; and the West Fork Complex , which is still burning 0% contained, and has so far burned more than 83,004 acres. Photos of an affected area, arranged  in chronological order. Just today, we watched a wildfire almost in our backyard, and saw the firefighters putting it out. We packed up in case we had to evacuate, but they got it under control and put it out. They had a helicopter with a wate...

Six days ago, a fire started in Black Forest, Colorado. The wind was very strong, and the fire quickly grew to become the most destructive fire in the history of Colorado. The smoke cloud looks a lot like this cumulus cloud; both were formed from warm rising air. That afternoon, I was able photograph the smoke cloud. You can see one of my photos at the top of this post. Notice the lighter area near the top of the cloud; that's caused by water vapor condensing out of the smoke. The following day, the air where we live was full of smoke from the fire. Then the wind changed and blew the smoke away, and we had fresh air for a while. That night, we were smoked out again. Wind that keeps changing over a wildfire can be bad. As we later learned, the fire had turned around and burned areas that had originally been spared. Not good. As of today, the fire is still burning, 75% contained. It has so far destroyed at least 483 homes and partially damaged 16 homes. Luckily, only 2 people we...

I recently sent a letter to Astronomy magazine about one of the articles in the April 2013 issue. The article was titled Astro April Fools  and was written by the columnist Bob Berman. I didn't like how lightly Bob treated Y2K, so I wrote the following letter: I have been a subscriber to Astronomy magazine for about 3 or 4 years, since I was about 12. Probably my favorite part of Astronomy magazine is Bob Berman's Strange Universe. However, in the April 2013 issue, Bob seems to treat Y2K a little too lightly. Although not as bad as advertised, there really were dangers; computers really did fail, and bad things did happen. Caption: A French sign displaying an inaccurate date because of the Y2K bug. Image taken from Wikipedia. Think about a normal computer problem, like the one that happened a few weeks ago: an airline's computers were down for only a couple of hours, but it cost them thousands of dollars. When something like this happens, the computer can be reset; o...

Last Friday I went skiing at Arapahoe Basin. Yes, there's still snow up there - but the warm weather is melting it, resulting in conditions known as Spring skiing. The water from the melted snow collects in valleys and trenches, forming ponds excellent for skimming. Skimming is skiing on water. To skim a pond, the upward force from the skis must exceed the skier's weight, and it must continue to exceed his weight until the skier gets across the pond. The force is determined by the skier's forward velocity, the surface area of the bottom of his skis, and the angle of his skis. On Friday when I visited Arapahoe Basin, I skimmed a few ponds. It's lots of fun, as long as you don't slow down too much halfway through the pond. Here's a video from my trip:

Finally - it's nice and warm outside. The meadowlarks are singing, and cumulus clouds fill the sky. In some places, this kind of weather has been going on for the past couple of months. Where I live, though, we've been having cool weather, so a 70° day seems very warm. Here are some of the pictures I took today: The photo above is of some purple mustard flowers. I really don't like purple mustard, but unfortunately it always comes with summer where I live. Sure, purple mustard might look okay, but it smells awful. This is a western meadowlark. I wanted to get a photo showing his breast, which is yellow with a black V, but he was always facing the wrong direction. Whenever I moved to a different angle, he changed position accordingly. So I had to be satisfied with a photo of his back. Dark, big clouds, with precipitation. Precipitation is what water is called when it condenses and falls out of the sky. Rain and snow are forms of precipitation; so is hail. Meteors are not. A ...

Photos of seeds from yesterday, to scale. The onion is the one on the left. A couple of days ago I planted 3 seeds in a clear glass jar, so I could watch them germinate. 2 of the seeds came from one of my basil plants, and the other came from a green onion plant. This is partly a test on the quality of my home-grown seeds, but also a fun gardening activity; after all, who wouldn't like to sprout  some seeds and watch them grow? Here's how you can make your own sprout jar: 1. First make sure you have some seeds you can use. Popcorn kernels work very well, if they haven't been popped yet; the better they pop, the better they grow. You can also use dry uncooked beans. 2. Acquire a small clear tube of some sort. I used an empty spice jar with the label removed.  3. Fold and/or cut a paper towel until it is as wide as the jar is tall. Then roll it up and put it inside the jar. Try to make the paper towel tight against the sides of the jar. 4. Add seeds to the jar. Place the se...

Yesterday I learned about something really cool called a Halbach array. It's a special arrangement of magnets that has a magnetic field on one side, but not the other. The array and its effect were discovered in 1973 by John C. Mallinson, but it was named after physicist Klaus Halbach, who invented the array 7 years later - not knowing someone else had already gone to the trouble. Halbach array, showing approximate field lines. The way the Halbach array works is similar to a bunch of lined up horseshoe magnets. There are North and South poles, but they are all on the same side of the row. Horseshoe magnets are clumsy, so in the Halbach array, regular bar magnets are used instead. The magnets are oriented so that their magnetic fields match those of the horseshoe magnets they're replacing; that way, the effect is nearly the same. A perfect Halbach array is only magnetic on one side, greatly reducing stray magnetic fields that can interfere with other equipment; and since the mag...