blue light
rallain | April 21, 2009I am not sure if First Excited State posted this as a blog entry, but it was mentioned on twitter. Question: why are sparks blue? My first gut response was that this is the blackbody color. Wrong for several reasons. The short answer is that sparks are blue because of the colors given off from nitrogen and oxygen when they are excited.
In order to make this post longer than necessary, let me say something about blackbodies. A blackbody is an object that emits radiation due only to it's temperature. Since it does not reflect anything, it looks black at room temperatures. You can make a…
grrlscientist | November 7, 2007tags: researchblogging.org, birds, migration, cryptochrome, blue light, garden warbler, Sylvia borin, magnetic compass, avian cryptochrome 1a, ornithology
Garden Warbler, Sylvia borin (Boddaert, 1783)
Blakeney Point, 16th September 2006.
Image: Matthew Rodgers [larger image].
Every year, millions of birds migrate to their breeding grounds and then back to their wintering grounds again. These birds' journies cover anywhere between several hundred to many thousands of miles, even when the skies are cloudy or dark. How do birds unerringly find their way to their destinations? Thanks to…