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Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 3:37 pm
by xer0s
I can't quite grasp the concept of looking at galaxies and other objects which are at the beginning of their life after the big bang.  So these objects are closer than we are to the origin of the big bang?  How would we be father away and yet not as old as these objects?  It would make sense to me, the farther away from the location of the big bang, the older you would be.  Could you clear this up?

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 3:39 pm
by scared?
lol...

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 3:41 pm
by scared?
Image

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 3:43 pm
by Plan B
Image

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 3:43 pm
by Κracus
xer0s wrote:I can't quite grasp the concept of looking at galaxies and other objects which are at the beginning of their life after the big bang.  So these objects are closer than we are to the origin of the big bang?  How would we be father away and yet not as old as these objects?  It would make sense to me, the farther away from the location of the big bang, the older you would be.  Could you clear this up?

Light travels from point a to point b. What you see is light. If light takes x number of years to travel from point a to point b then people on point b are seeing what happened x years ago.

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 3:44 pm
by xer0s
lol, I actually tried to ask Neil this question during his last AMA on reddit. But it's impossible to get past the other hundreds of questions for him...

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 3:46 pm
by obsidian
Galaxies, stars and planets weren't all formed at the same time after the Big Bang. It just marks the beginning of anything. Besides, you hardly have time to worry about these things seeing as how the LHC is going to create a black hole and kill us all anyway.

Neil would have facepalmed.

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 3:46 pm
by Ryoki
Image

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 3:46 pm
by scared?
i see dumbos...EVERYWHERE!!!...

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 3:47 pm
by Plan B
xer0s wrote:lol, I actually tried to ask Neil this question during his last AMA on reddit.
LEAVE NEIL ALONE!!1 >:'-(

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 3:49 pm
by MKJ
obsidian wrote:Galaxies, stars and planets weren't all formed at the same time after the Big Bang. It just marks the beginning of anything. Besides, you hardly have time to worry about these things seeing as how the LHC is going to create a black hole and kill us all anyway.

Neil would have facepalmed.
also, their mass influences the speed at which they travel through space. we could be younger but still have taken them over.

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 3:59 pm
by xer0s
Κracus wrote:
xer0s wrote:I can't quite grasp the concept of looking at galaxies and other objects which are at the beginning of their life after the big bang.  So these objects are closer than we are to the origin of the big bang?  How would we be father away and yet not as old as these objects?  It would make sense to me, the farther away from the location of the big bang, the older you would be.  Could you clear this up?

Light travels from point a to point b. What you see is light. If light takes x number of years to travel from point a to point b then people on point b are seeing what happened x years ago.
I've always understood that. I don't think you understand what I'm asking. I think obsidian gets it better...

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 4:15 pm
by Nightshade
Plan B wrote:Image
:olo: NAILED IT.

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 4:19 pm
by obsidian
Why does Australia have all the weird-as-fuck creatures? It's like aliens visited the continent and left behind their petting zoo.

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 4:20 pm
by MKJ
not cool to talk about the abbos that way, bro.

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 4:22 pm
by obsidian
:(

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 4:38 pm
by scared?
abbos are fucking ugly ppl...

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 4:48 pm
by xer0s
Ok, so the Milky Way is around 13 billion years old, and we are looking at a galaxy that is only 500,000 old. The astrophysicists say "We are looking at an object that was created only 500,000 years after the big bang.". Yet we are farther away from the big bang. Shouldn't it have expanded away from the big bang for the other 12,999,500,000 years? It's hard to explain. I'm sure I'm just confusing myself. Not sure though...

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 4:51 pm
by scared?
holy shit moron...stfu...

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 5:31 pm
by bitWISE
xer0s wrote:Ok, so the Milky Way is around 13 billion years old, and we are looking at a galaxy that is only 500,000 old. The astrophysicists say "We are looking at an object that was created only 500,000 years after the big bang.". Yet we are farther away from the big bang. Shouldn't it have expanded away from the big bang for the other 12,999,500,000 years? It's hard to explain. I'm sure I'm just confusing myself. Not sure though...
Inflation. Space can actually travel faster than the speed of light. Because its space, fuck you.

So at the big bang, you have quantum fluctuations that trigger the release of positive, kinetic inflationary energy. That point of space nearly instantly expands by unfathomable amounts (many times the speed of light). Like heat is the byproduct of most releases of energy we know, matter was the byproduct of this energy release. So you get a uniform spread of matter across a huge area (an infinite area with finite time from our perspective, a finite area with infinite time from outside the bubble). After inflation happened, the only force pushing galaxies out is dark energy fighting against gravity.

To answer your question directly, yes the galaxy has been "expanded away from the big bang for the other 12,999,500,000 years". But we can't see that light yet. We can only see the picture that was taken when the light that is just now reaching us, left that galaxy. Imagine watching a football game by having someone mail you a stream of poloroid shots. You'll eventually see the entire game as it happened, but you've got to account for the delay of the postal system. You aren't watching it in real time.

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 5:35 pm
by HM-PuFFNSTuFF
Xeros, here is the thing... everything is expanding from everything else at same rate. So technically you are the center of the universe and everything in it is expanding away from you. I hope this helps.

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 5:47 pm
by EtUL
http://csep10.phys.utk.edu/astr162/lect ... nsion.html

Check that out and "The two dimensional analogy". The balloon analogy helped me understand space expansion, even though it isn't a perfect analogy.

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 5:52 pm
by seremtan
"farther away from the big bang"

oh lawdy

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 5:56 pm
by Doombrain
xer0s wrote:I can't quite grasp the concept of looking at galaxies and other objects which are at the beginning of their life after the big bang.  So these objects are closer than we are to the origin of the big bang?  How would we be father away and yet not as old as these objects?  It would make sense to me, the farther away from the location of the big bang, the older you would be.  Could you clear this up?
Image

Re: Ok, all you astrophysicists...

Posted: Tue Mar 20, 2012 7:01 pm
by Tsakali
Image