Tuesday, September 27, 2011

Looking Up



The title of this post, and of my blog, comes from this talk by astronomer Neil DeGrasse Tyson, in which he defends the importance of maintaining the space program. It is important, he says, for people to start "looking up," to realize that there is so much more out there than the things people worry about day to day.

I don't mean to inflate the importance of astronomy, or to belittle the real and significant problems facing the world today. The point, I think, is that discovery is never a waste of time.

For example, I did research at Caltech over the summer, and I'll be the first to admit that I don't think my results have any practical value. But I (and hopefully you!) don't see it as a waste of time.

I did work studying Ultraluminous Infrared Galaxies (or ULIRGs), objects emitting over a trillion times the luminescence of the sun, mostly in the infrared (as you may have guessed). This huge radiation output is generally the result of two things: the accretion of mass by a galaxy's central, supermassive black hole, or the widespread formation of new stars. Both of these phenomena are often caused by merging systems; that is, this is what happens when galaxies run into each other at top speed. Awesome.

But there's a problem. The galaxies we're studying contain massive amounts of dust floating around. This dust intercepts the radiation from the black holes and new stars, and re-emits in the infrared. So, if you wanted to know whether a particular galaxy was powered mostly by a central black hole or by new stars, how would you find out? By looking at this:

The graph is the result of a program that breaks down the emission spectrum into several sources, including stellar light and various temperatures of dust. A galaxy powered by a black hole results in a different decomposed spectrum than one mostly powered by star formation.

Now, this sort of information has pretty much no impact on everyday life. I don't really see how it could. But we don't seek to learn only to solve the problems standing immediately before us, but also to drive a process of discovery that I think enriches society. Literature won't feed the hungry, but surely there is no doubt of its cultural value. A value that is, I think, similar to that of looking up.