Crash Course Astronomy: Tripping the Light Fantastic

Contributed by
Jul 11, 2015
<?xml encoding="utf-8" ?>

For the two dozenth episode of Crash Course Astronomy, we have to take a step away from the straight astronomy stuff and talk a little bit about light. After all, pretty much everything we know about the Universe is information sent via electromagnetic radiation, and as we press on into the cosmos we’ll need to know something about how it works.

So let me illuminate you:

You probably don’t think much about light, but holy wow does it store a lot of information into teeny little photons. This is a part of astronomy, of science, that reaches into my brain and tickles my mind; we see objects so far away that just the numbers describing their distance seem huge beyond imagining, yet that trickle of light tells us what those objects are, how far they are, what they’re made of, how hot they are, how rapidly they’re moving, whether and how fast they’re rotating, how strong any magnetic field they might have is, even giving us hints of the existence of things we can’t see. And even then, there’s still so much more.

If I were of the anthropomorphizing type, I’d say the Universe was desperately trying to tell us as much about it as it can. It’s just the consequence of the laws of physics, of course, but that removes none of the wonder or majesty of what we can learn. The Universe may not care what we know, but we do.