Monday, May 4, 2009

Hubble Ultra Deep Field

Today we're going to talk about what you can see and can't see when you look up into the night sky. Let's see where it takes us.

Step outside tonight and gaze into the heavens. Almost all of the lights you see up there are stars that are in our very own milky way galaxy. If you're like me, you live in a city and can't see but a handful of stars. So, thanks to the wonders of modern technology, here is what the sky looks like from the middle of the desert (definitely click on this to see the big version, definitely).

Looks pretty cool, huh? That streak of light across the sky is the milky way galaxy. The bright spot toward the right side is the center of the galaxy, which by the way, encircled by an unimaginable number of stars is our very own supermassive black hole.

Anyhow...anything you see in the sky that is not a star from our galaxy is either a planet or another galaxy, and we can't see too many of those. There are only 4 galaxies, including our own, that can be seen with the naked eye, and they're all so far away that they look like stars from here. So, almost everything we can see with our eyes in the night sky is, astronomically speaking, pretty darn close by.

Let's imagine taking a trip past what we can see with our naked eyes. Past our galaxy, past our galaxy neighbor Andromeda, waaaay past...

Let's imagine... let's imagine we made a super strong telescope, blasted it into outer space so there was no visual disturbance from the movement of the gas molecules in our atmosphere, aimed it at the darkest patch of sky we could find, so dark that we'd never been able to see anything there before, ever... and then we snapped a picture and kept the shutter open for 4 months

I wouldn't be talking about it if we hadn't already done just that. Here's what the picture looks like (again, click on this for the full-size version):

I'll give you a second.  Seriously, stop reading this crap and go back and stare at that picture some more. 

Looks kind of like a bunch of stars at first, huh? As you look closer you realize that every single one of those things you see is a motherfucking galaxy. A galaxy... As a reference, our galaxy contains around 100 billion stars. Now try and count all the galaxies in this photo, multiply that by 100 billion, realize that this photo is of an incredibly tiny pin-prick point in our sky, and now make your best guess at how many other colonies of life exist in the universe. My guess is 69. What's yours?

As an added bonus to how amazing this photograph is, even at the speed of light, the photons emitted from these galaxies took about 13 billion years to reach the telescope's lens. Now, the universe is only around half a billion years older than that, so that means that this is a picture of the universe shortly after the beginning of time. Think about that...the beginning of time...of time...time. time. time. what is time? how could it begin? can it end? how are we moving in time and why can't we control it? who are we?