which way to the big bang

[MeteorWayne]

The hard part is grasping the concept that the big bang is everywhere, no matter which direction you look. People thing in terms of an expanding explosion, but the big bang isn't like that. It's all of space expamnding from every point..

 

[SpeedFreek]

IF the CMBR image is the BB, then wouldn't it make more sense for it to be uniform in colour (and temperature) and not hold so many pockets of differing temperatures?

No volume of gas can be completely uniform in temeperature - there will always be quantum fluctuations, due in part to the uncertainty principle. It was during the inflationary epoch that these quantum fluctuations were stretched into large areas with an ever-so-slightly different temperature to the areas around them. The differing temperatures are shown as anisotropies in the CMBR and the difference in temperature is incredibly small - the colouring is designed to emphasise very small differences indeed.

 

[SpaceTas]

I have a post elsewhere on a very similar question. Sppedfreak has done a good job.
Would be good if we could have a "classic answers" system.

My reply to the question "what was before the big bang ?" is by way an analogy for nothing.

What do you "see" out the back of your head?
Nothing not black, just no-thing ... no information at all.

 

[JohnniG]

Yes. They point there telescopes in any direction and peer as deep as they can. But we can't look all the way back to the big bang because the light from the bang hasn't had, and will never have, time to get to our eyes, because of the constant expansion. At least, that's my understanding of it.

MeteorWayne can probably answer your questions better than I.

But as far as seeing into the future to witness the Big Crunch, that makes no sense to me. We can see only the past when we look out to space, not the future.

That's my thoughts exactly

 

[xxMIKExx]

The hard part is grasping the concept that the big bang is everywhere, no matter which direction you look. People thing in terms of an expanding explosion, but the big bang isn't like that. It's all of space expamnding from every point..

I can understand that all space is expanding from every point. but surely that just implies that the Universe is made of an "elastic" material and has an overall shape of a ball. Tho bubble would probably be a better word.
If we had a timelapse video of the entire Universe and played it backwards, then everything in space would move towards everything else and eventually arrive at a starting point. The BB.
Like drawing points on a deflated ballon then blowing it up. Every point on the balloon will move away from each other, but if you de-flate it, then the points will move back to there starting points.

 

[SpeedFreek]

I can understand that all space is expanding from every point. but surely that just implies that the Universe is made of an "elastic" material and has an overall shape of a ball. Tho bubble would probably be a better word.
If we had a timelapse video of the entire Universe and played it backwards, then everything in space would move towards everything else and eventually arrive at a starting point. The BB.

The problem is that we cannot view the universe from the "outside" - we do not think it is expanding into something else.

The timelapse video can only be made from the inside, so when you run the film backwards everything in space would move towards the camera. Wherever you put the camera, it has to be inside the universe.

Using the balloon analogy, the camera has to sit on the surface of the balloon along with everything else in the universe. With the balloon analogy, there is no inside or outside of the balloon, there is only the surface.

If the universe were like the balloon, there is no direction you could take that would lead you towards the edge of the universe. Whichever direction you travelled in, if you could beat the rate of expansion you would find yourself back where you started!

The balloon analogy takes the whole universe and maps it onto the 2 dimensional surface of a sphere. The inhabitants of the balloon universe are 2 dimensional and have no concept of "up" or "down", they can only see in 2 dimensions across the surface of the balloon.

So what if we take that principle and apply it to our 3 dimensions of space? Perhaps our universe is the 3 dimensionsal surface of a 4 dimensional shape, but we cannot perceive that 4th dimension. So, a straight line through space could actually curve in a higher dimension. If, for instance, the universe was the surface of a 4D sphere, then a straight line in any direction (as viewed from the inside) would actually be part of a giant 4 dimensional circle. There is no edge to the universe, in this scenario.