Just a quick thought about something that I find particularly interesting - Quasars. First, I'm obviously not an authority on these things, nor am I exactly the best person to come to regarding astrophysics knowledge, but let's face it, space stuff is pretty awesome. So, first, to my understanding, Quasars are basically highly energetic, nuclei of very distant galaxies which are some of the most luminous objects in the universe, and consequently, were some of the earliest examples of redshift. It's believed that quasars are formed by accretion of material in supermassive black holes, or in other words, stuff getting pulled by the very powerful gravitational field around supermassive black holes, and the very bright light is what energy is immediately outside the event horizon (as anything past the event horizon is impossible to see - hence, black holes). Now, one may ask "what the is redshift, and why is it important? Before getting into that, I'd like to quickly highlight some of the more interesting bits of history about quasars. Early on, quasars were first "seen" in the 1950's with radio telescopes as radio sources, but without a visible image attached to them. It wasn't until a decade later that, with really big telescopes (like the Hale Telescope at Palomar) that redshifted spectral lines were observed. Fastforward a few years, allow for some of us to be born, and now, over 200,000 quasars have been observed, no just as spectral lines, but as actual, resolved objects, thanks to the construction of a lot of really big telescopes. So now, redshift - Why's it important, what the is it, and what significance does it hold? Redshift is, essentially, the Doppler effect happening with light, rather than sound. In a nutshell, the Doppler effect is observed when a wave-emitting source is moving either towards or away from a (relatively) stationary object, and because of the motion either shortens or lengthens the frequency (and consequently, the wavelength) of the wave, whether it be sound or light. Now, in the case of quasars, the redshift implies that the quasars, being extremely luminous and very very far away, emit electromagnetic waves which are detected by whatever instruments we use here on earth. The spectral lines detected by us turn out to be shifted further into the red region that they should be, hence the term redshift. The significance of this lies in the fact that the shift towards red implies a Doppler effect, and by extension, that the quasars are in fact moving further and further away from us over time. This would then imply that the universe is not stationary, but is in fact expanding. This further holds some implications related to special relativity, which coincidentally, falls into quantum mechanics and I feel a little lazy about trying to talk about in this post. Maybe next time? Yeah probably. But anyways, pretty neat stuff. Here's a cool picture to distract whoever is reading this (artist rendering of what a quasar might look like):

OOOOH PRETTY PICTURE