Ask Ethan: Where did the Big Bang happen? (Synopsis)

"The world you see, nature's greatest and most glorious creation, and the human mind which gazes and wonders at it, and is the most splendid part of it, these are our own everlasting possessions and will remain with us as long as we ourselves remain." -Seneca

Asking where in space the Big Bang happened is like asking where the starting point of Earth’s surface is. There’s no one “point” where it began, unless you’re talking about a point in time. The reality is that, as far as space is concerned, the Big Bang occurred everywhere at once, and we have the evidence to prove it.

Our view of a small region of the Universe, where each pixel in the image represents a mapped galaxy. On the largest scales, the Universe is the same in all directions and at all measurable location. Image credit: SDSS III, data release 8, of the northern galactic cap. Our view of a small region of the Universe, where each pixel in the image represents a mapped galaxy. On the largest scales, the Universe is the same in all directions and at all measurable location. Image credit: SDSS III, data release 8, of the northern galactic cap.

If the Big Bang were an explosion, we would discover ourselves in a Universe that had a preferred location with different densities surrounding it, but instead we see a Universe that has the same density everywhere. We’d see a Universe that looked different in different directions, yet we see one that’s uniform to better than one part in 10,000 in each direction we look. And we see a Universe that exhibits zero spatial curvature: one that’s indistinguishable from flat.

The appearance of different angular sized of fluctuations in the CMB results in different spatial curvature scenarios. Image credit: the Smoot group at Lawrence Berkeley Labs, via http://aether.lbl.gov/universe_shape.html. The appearance of different angular sized of fluctuations in the CMB results in different spatial curvature scenarios. Image credit: the Smoot group at Lawrence Berkeley Labs, via http://aether.lbl.gov/universe_shape.html.

The Big Bang happened everywhere at once. This is how we know it, and this is what it means.

More like this

Our view of a small region of the Universe, where each pixel in the image represents a mapped galaxy.

Astounding. What size is that "small region of space?"

“The reality is that, as far as space is concerned, the Big Bang occurred *everywhere* at once…”

If that’s true, then it seems fair to say the Big Bang occurred *nowhere*.
...................

Other notes:

1)
“It’s true that the Universe was similar to a tremendous, energetic, expanding fireball in the very earliest stages…”

Not very similar, apparently, since an expanding fireball has a center *point*.

2)
“The evidence for this is overwhelming, and comes from the Universe itself. The Universe, if we look at the large-scale structure, of how galaxies cluster, of what the leftover glow from the Big Bang looks like, of what the average density is in regions more than a few hundred million light years in size…”

How does the average density of the one billion light year-wide Boss Great Wall compare to the average densities you’re talking about?

3)
“The fact that the Universe is homogeneous and isotropic tells us that the Big Bang happened simultaneously, some 13.8 billion years ago, at all locations equally. *But we can’t see it at all locations equally; we can only see it from where we are.”*

Then, by definition, the universe is not isotropic.

4)
“Well, we’ve made those observations, and what we’ve found is overwhelming: the Universe is flat, as far as we can tell. Really, really flat.”

Except for the overwhelming facts that you’re not flat, and I’m not flat, and the earth’s not flat, etc.

At least, “as far as we can tell.”

5)
“The Big Bang did not happen at a point, and the way we can tell is through the *extraordinarily high* degree of *isotropy* and *homogeneity* of the Universe.”

See 3) above.

By See Noevo (not verified) on 30 Jul 2016 #permalink

amazing sn. All these months of reading and posting and you still haven't learned enough to develop a valid objection. Your #4 here is, perhaps, your most amazingly stupid to date.

Paul, I'm not sure what your reference is meant to indicate. sn's "perspective" is that of a denier of science, willfully ignoring and misrepresenting what Ethan (and others around these blogs) writes.

Dean,

It was simply a reflection that "a small region of space" gets bigger and bigger, or smaller and smaller, depending on our own perspective. It also made me think of Cantor and infinity between two numbers which made me run into Zeno's paradoxes

By Paul Dekous (not verified) on 31 Jul 2016 #permalink

Your #4 here is, perhaps, your most amazingly stupid to date.

Both #3 and the intro are close behind. At least he didn't include the milk routine in this list of moldy oldies.

Nope. Not good enough. If we are living in a presumably ~roughly spherical expanding universe, there must be a center point. It is the location of that center point people are asking about, not for more hand-waving Me-generation magical obfuscating word games from the likes of the TV cult of personalities and their satellite bloggers. Have the balls to say "we don't know" and move on.

By Andrew Jenkins (not verified) on 31 Jul 2016 #permalink

Nope. Not good enough. If we are living in a presumably ~roughly spherical expanding universe, there must be a center point.

Reading for comprehension isn't your strong point? This was clear, concise, and not an "obfuscating word game" at all. (At least, not if you put forth an honest attempt to understand.)

"If we are living in a presumably ~roughly spherical expanding universe, there must be a center point."

NO there isn't.

there must be one for a 3d sphere in 3d space, but what's the "center point" of a 3d sphere in 2d space???

If the universe were infinite in size, it's the same size in each direction, yet has no center point, since each point, no matter how far away from another defined point, is just as far from each infinite extent as any other. This scenario, though not the case as thought to be reality in our universe, comports to every requirement you have, yet the conclusion you made does not apply, indicating that AT THE VERY LEAST you need to define more requirements.

[Andrew Jenkins]“If we are living in a presumably ~roughly spherical expanding universe, there must be a center point.”

[Wow] NO there isn’t...

While I agree Wow, I think Andrew's mistake is a pretty common one and so worth explaining in simple terms. So here's my attempt.

Most laypeople are familiar with the 'expanding balloon' analogy (if not, look it up, then come back here for the rest). The important, hard-to-grasp point that laypeople need to remember about the balloon analogy is that the universe is represented by the surface of the balloon, not its interior space. The 'interior space' of the balloon would not be in our universe or be a part of our universe. Now as a balloon shrinks and grows, you look at the surface, and you see that there is never a center on that surface. And that is why (to the best of the analogy's ability to represent complicated physics) we say there is on center or origin point.

The key point, or one of them, is that according to General Relativity (which so far has been confirmed by everything from planet precessions to GPS calculations to gravitational waves), our universe has no edges. You could travel forever and never hit a wall. If the speed of light were much faster than it is, you could theoretical arrive back at your starting point (eventually) by traveling at the speed of light in any direction away from that starting point, but the universe is too big and expanding too fast relative to c to allow that.

Without edges, there is no way to define a center - at least I can't think of one. One could make a mathematical model that embeds a boundaryless shape in higher dimensions so that the extra dimensions provide boundaries, but unless and until there is a way to get access (measurements, evidence) to those higher dimensions that would be just speculation.

I also can't see anything without an edge - I can't see emptiness (nothing to see there, better move on) so it is impossible for me to visualize the shape of our universe.

The Argument From Incredulity says that Einstein and GR must be wrong, but the AFI does not have a good track record. Anyway, GR is the best model we have, and its assumption is that this universe has no edges and therefore no unique center.

Philosophically, that makes some sense to me. The universe is all there is, and how can all there is have boundaries? Not that the universe cares what my philosophy says.

#11 Of course the surface of the balloon in the analogy has a center. It's where the air goes in!

@13: true, the balloon analogy suffers from the fact that balloons are not topologically spheres. In terms of topology, they're actually plates (in the same way donuts and cups with handles are the same topological shape)! :) That's why, with analogies, its important to understand what properties of the analogous thing are the similar to thing you're trying to describe, and what properties aren't. The balloon's air hole is not analogous to any feature of/in the universe...at least, we don't think it is... :)

Typo: "theoretical" should be "theoretically".

Meanwhile, a visualization of sorts just occurred to me. I visualize an infinite volume of nothingness - since it contains nothing it might as well be infinite. Within that volume, random specks of something occur, with the following rules: something includes what we think of as normal space (which is not nothing, it has vacuum energy); something that is moving within something can travel through nothing instantaneously to the next patch of something; and the patches of something are increasing over time.

This is similar to higher-dimension embedment, using the "nothing" instead of a higher dimension, and is just another analogy so there is probably something wrong with it, but until I find out what I will use it.

EpiPete #13 says
“Of course the surface of the balloon in the analogy has a center. It’s where the air goes in!”,
and he may have inadvertently made a good point.

If the unseen/unknown/un-understood placeholder named “dark energy” is responsible for the alleged accelerating expansion of the universe, then,
FROM WHERE does this energy exert its dark powers?

P.S.
Redux:
Ethan: “It’s true that the Universe was similar to a tremendous, energetic, expanding fireball in the very earliest stages…”

Me: “Not very similar, apparently, since an expanding fireBALL has a center *point*.”

By See Noevo (not verified) on 01 Aug 2016 #permalink

If the unseen/unknown/un-understood placeholder named “dark energy” is responsible for the alleged accelerating expansion of the universe, then,
FROM WHERE does this energy exert its dark powers?

If it weren't for the fact that you have soundly established yourself as an effectively thought-free troll whose interest lies solely in latching onto individual words out of some weird obsession with trying to get people to appreciate your pratfalls, you would have understood that all you have done is demonstrate that you don't understand the basic point.

But you're willing to try to leverage this for attention-whoring, of course. It's a pretty crappy stock-in-trade, if you ask me, but you're the one who has to stew in a self-made kettle of "chastity" (heh), misogyny, racism, hypocrisy, and comfortable, rank ignorance.

Try to understand this. It doesn't get much simpler. Try again when you can at least explain what a(t) is. I wil again not be holding my breath.

Try again when you can at least explain what a(t) is. I wil again not be holding my breath.

My guess is he will take the convention a(t) = 1.0 at the present time to be evidence of design. OMG, this universal factor just happens to equal 1.0 precisely at the time humans appear in the universe? What're the odds of that? LOL.

It would not be a surprise if sn have this

"Sadly it doesn't have a simple analytical form, "

as a reason to dismiss a(t) as another unsupported feature. After all, in his world, if it can't be seen it doesn't exist.

In all fairness, I'm not sure what the Big Bang is anymore. When first learning about the concept it seemed dead simple. It was the beginning of time, space, and everything. The universe was expanding and working backwards you'd reach a point of a naked singularity or 'primordial atom'. Even in this article @Ethan refers to is as a day without a "yesterday". That is great and all, but its wrong or it isn't the big bang.

In the yesterday before the Big Bang was expansion. It isn't known if that lasted the tiniest fraction of a second or an eon, but it took place before the Big Bang. If all the matter in our universe was in a naked singularity or primordial atom then it would have a location because the universe had already expanded.

Another problem is the size of the universe. If it all started from a point then it would only be 46 billion light years across, but it isn't. According to this image @Ethan likes to use in such articles, stars and galaxies extend as far as anyone can imagine.

For right or wrong, I'm now seeing the Big Bang as more like the instantaneous appearance of heavy fog everywhere inside a container that has been explosively decompressed. The Big Bang was a time not a place, and does not refer to the construction of the container which happened at some point earlier.

In all fairness, I’m not sure what the Big Bang is anymore.

As it happens, Bee addressed this topic just over a week ago.

@Narad

Its for this exact reason that the Big Bang isn't fun. You can't cobble together different sources to gain a solid understanding because all of the different sources could all be talking about something different.

You can't even definitively state the Big Bang didn't have a location. In the 'Multiverse' article @Ethan stated there could have been multiple Big Bangs all stemming from the same inflationary state. If there are multiple Big Bangs all in the same space then each would have a location relative to each other.

If you are confining proclamations to only our observable universe where there was only one Big Bang, then again it could have a location because if the universe curves back on itself then space was somewhere between 250 and infinite times larger than our observable universe. If the Big Bang creating our visible universe did not fill out the entirety of space then it had a location. Its perimeter would be beyond the edge of our visible universe but that is not the same as it not existing.

There is much that is understood about the beginnings of our observable universe, and there is much that is unknowable. Figuring out who is giving it to you straight and who is engaging in unprovable speculation is tougher when even the experts can't or won't iron out the vocabulary.

"You can’t cobble together different sources to gain a solid understanding because all of the different sources could all be talking about something different. "

No, you can do it but only if you're careful about what the source you're reading is talking about.

This is no different from ANY discussion on ANY topic that uses a human language.

"You can’t even definitively state the Big Bang didn’t have a location."

Yes you can. Because any "location" in the multiverse would be outside our universe and therefore unavailable, just like "the taste of pink" isn't possible to exist by definition.

I always suspected I was the center of the universe, and now I had scientific confirmation.

By Roger Carlson (not verified) on 07 Aug 2016 #permalink