Time for the sun! Coincidence had a question about solar cycle 24 (what is it, how long are they) hitting my email box the day before I ran in to an astronomer friend who is working with the recently-launched solar dynamics observatory.
For the first, the obvious answer is the correct -- this is the 24th time since records started that the solar cycle has been on the increase. 'solar cycle increase' meaning, in part, the sunspot counts are increasing. But the sun does a lot more than just get spots. The Space Weather Prediction Center keeps an eye on the sun, including these other things (go have a look, see the sun as if you had x-ray vision!). And, naturally, tries to predict things that are influenced by solar activity. The cycles average something like 11 years, but vary greatly from cycle to cycle (8-15 years). The activity minimum we are now leaving was unusually deep and unusually long.
On the second, I'll mention that he (William Bridgman) blogs at Dealing with creationism in astronomy. An article that I'll be taking a look at, and encourage the more technical readers to do likewise, is his The Cosmos in Your Pocket: How Cosmological Science Became Earth Technology. I
Here's his abstract:
Astronomy provides a laboratory for extreme physics, a window into environments at extremes of distance, temperature and density that often can't be reproduced in Earth laboratories, or at least not right away. A surprising amount of the science we understand today started out as solutions to problems in astronomy. Some of this science was key in the development of many technologies which we enjoy today. This paper describes some of these connections between astronomy and technology and their history.
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