Where was the Big Bang located? In which constellation? Should we observe more young galaxies in that direction and more old ones in the opposite direction?

This diagram shows changes in the rate of expansion since the Big Bang. The shallower the curve, the faster the expansion rate. There's a notable change in the curve around 7.5 billion years ago, when astronomers think a mysterious, dark force caused objects to fly apart at a faster rate. NASA/STSci/Ann Feild
This diagram shows the expansion of space over time..
NASA / STSci / Ann Feild

You've got the commonest misconception about the Big Bang: that it happened at some particular spot in preexisting empty space, like an exploding hand grenade with galaxies for shrapnel. Actually, the Big Bang gave birth not just to matter but to space itself. Space then expanded so the matter in space thinned out. In other words, the Big Bang happened right where you're sitting just as much as anywhere.

Here's the short, elevator-speech version: The Big Bang happened everywhere at once. And everywhere started small and grew big. Wrap your mind around that, and you've got it exactly.

— Alan MacRobert

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Galaxies & the Universe

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Mark_Neal

July 13, 2022 at 1:33 pm

So, when we're looking at an object 3 billion light years away we see the galaxies closer together and therefor visibly a greater density no matter where we point the telescope. It stretches my mind. When we are looking at a photo from, for example, the Webb telescope with a great distance/time depth, are we seeing objects (galaxies) or vastly differing ages? Is it true then that no matter where we look we are looking at the original singularity? No matter where we look we are looking at the same, infinitesimally small location?

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Monica Young

July 13, 2022 at 4:00 pm

Interesting question! So yes, the deep field is a good example of Webb seeing galaxies of vastly different ages because the galaxy cluster is closer than the background galaxies (the white and red galaxies, respectively). But we can only look back so far - we don't see all the way back to the Big Bang. The most distant galaxies in this image are still in a universe a couple hundred million years old.

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gabrielwolf

October 11, 2022 at 2:31 am

Say a hypothetical telescope could look back to 1 second after the Big Bang, or 0.1 seconds or 0.000001 seconds and so on (I think before there was even light, but ignore that for this hypothetical.) At some point the the images will be coming from a place so that hasn’t yet expanded as much as the universe has expanded now, or even as much as the universe had expanded 1 second after the Big Bang. Where is that located?

Did the universe expand equally in all directions from the Big Bang? Has it continued expanding equally in all directions? If so, isn’t there a center somewhere?

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Monica Young

October 11, 2022 at 2:06 pm

The issue is that the universe is not expanding "in all directions from the Big Bang" - the Big Bang was the beginning of the expansion of space itself. There was nothing for it to expand into. It can take a bit to wrap your head around!

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KaLi

May 5, 2023 at 7:16 am

One could still think of space as a balloon, that is blown into and the universe is the air in the balloon?

The question I was wondering about is: would it be possible to find the center of the balloon from the differential in the expansion speed in different directions and distances.

This would be the place where it all started?

What is there now?

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Monica Young

May 5, 2023 at 9:25 am

Hi KaLi, So the balloon analogy actually has the universe on the *surface* of the balloon, rather than the air inside it. Of course, analogies only take us so far - space is flat, not rounded like a balloon - but I hope that helps with understanding the analogy for the expansion of space.

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underthewronghat

September 18, 2023 at 9:53 pm

This sounds extremely coy, in fact, too coy to be scientific. I'll bite.

Another way to ask this question is to simply describe the motion of the universe. Mostly, we're looking at galaxies to see that motion.

The Milky Way Galaxy is travelling through (and with) space on a constant vector. Sure, we're wiggled by near galaxies, but we are not travelling omnidirectionally, as the "we're all always in the center" answer would imply. In fact other galaxies are travelling on a slightly different vector, and their light is shifted red, by the doppler effect.

And sure, space is spreading out. The Galaxy is spreading out. But all that stuff, which is spreading out, is still travelling awfully fast in one direction. So until we see some distant blue-shifted galaxies (which would indicate that some things are not spreading out, but coming together), I see no other explanation than all galaxies are proceeding on a different vector away from a point of origin.

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