# Was the universe infinitely large immediately after the Big Bang? **URL:** \ **Category:** Factual Questions\ **Created:** [October 19, 2024, 9:43pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983 "2024-10-19T21:43:49Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![AHunter3](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ahunter3/32/368_2.png) [@AHunter3](https://boards.straightdope.com/u/AHunter3)\ **Post date:** [October 23, 2024, 10:40pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/41 "2024-10-23T22:40:36Z")
> [@CoolHandCox](#): > > Yes and no ISWYDT ---
**Author:** ![EnolaStraight](https://avatars.discourse-cdn.com/v4/letter/e/41988e/32.png) [@EnolaStraight](https://boards.straightdope.com/u/EnolaStraight)\ **Post date:** [November 1, 2024, 3:46pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/42 "2024-11-01T15:46:02Z")
If it hasn’t been covered yet… At the Big Bang, mass and energy didn’t just expand into a pre-existing infinitely large empty volume. Space and Time themselves were created in the BB and have been expanding ever since. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [November 1, 2024, 3:53pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/43 "2024-11-01T15:53:38Z")
> [@CookingWithGas](#): > > Honestly I can deal with the idea of infinite time more easily than the idea of time being bounded. Well…if time and space are infinite then so are you. There is a finite way matter can be configured which means in an infinite universe there are an infinite number of “you” out there. You’re brain is ok with that? See: [Poincaré recurrence theorem](https://en.wikipedia.org/wiki/Poincar%C3%A9_recurrence_theorem) ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [November 1, 2024, 4:06pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/44 "2024-11-01T16:06:59Z")
My brain breaks when you tell me there is a boundary but you cannot tell me what’s “outside” the boundary. I still struggle with the idea that time is a dimension _of our universe_, and not some metadimension within which the Big Bang exists. That is, I understand intellectually that before the Big Bang there was nothing because time didn’t exist outside the Big Bang and so there was no “before” the Big Bang. I can write those words and explain it, and I might even have a chance at understanding the math, but I just can’t conceptualize it. Just like I know what a tesseract is but I can’t think in four spatial dimensions. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 5, 2024, 11:13pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/45 "2024-11-05T23:13:01Z")
> [@CookingWithGas](#): > > My brain breaks when you tell me there is a boundary but you cannot tell me what’s “outside” the boundary. Right, that’s normal. We can’t tell you what’s “outside the boundary” because there isn’t a boundary. ---
**Author:** ![whc.03grady](https://avatars.discourse-cdn.com/v4/letter/w/a6a055/32.png) [@whc.03grady](https://boards.straightdope.com/u/whc.03grady)\ **Post date:** [November 6, 2024, 5:16am UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/46 "2024-11-06T05:16:10Z")
Lol Off-topic, but Google’s AI recently told me that some of the largest US cities not on the Interstate highway system included Cheyenne WY and Salt Lake City. ---
**Author:** ![Johanna](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johanna/32/8318_2.png) [@Johanna](https://boards.straightdope.com/u/Johanna)\ **Post date:** [November 10, 2024, 7:56pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/47 "2024-11-10T19:56:58Z")
> [@whc.03grady](#): > > Google’s AI recently told me that some of the largest US cities not on the Interstate highway system included Cheyenne WY and Salt Lake City. That’s false in our universe; which universe was it talking about? ---
**Author:** ![Charlie\_Tan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/charlie_tan/32/12582_2.png) [@Charlie\_Tan](https://boards.straightdope.com/u/Charlie_Tan)\ **Post date:** [November 10, 2024, 8:46pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/48 "2024-11-10T20:46:29Z")
What I want to know is _why?_ So infinite energy is… well not somewhere, because that means a location and there are no locations at this point, but _in potentia_…? And then it 'splodes, for lack of better word. And expands faster than the speed of light, because…well, it’s not even light, just energy and distance is literally being made by inflation? But _why?_ ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [November 10, 2024, 9:29pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/49 "2024-11-10T21:29:13Z")
Why _what_? No-one talked about infinite energy and it is not necessarily the case that there was such in the big bang. I’ll make two points though that might point you in the right direction: 1. The “big bang” is a bit of a misleading name. Really it is the theory that the universe has expanded from a much denser state and it’s been verified by numerous lines of evidence. A lot of pop-sci stuff, and religious sites, talk about the big bang as being the theory of where the initial, maximally-dense singularity came from, and it just isn’t. That’s a separate thing and we don’t know yet. 2. As I alluded upthread (I think), there are overarching questions of how/why anything exists at all, and those are definitely in the “we don’t know” column. At this time it looks intractable and all current answers, whether scientific or religious, boil down to “A thing just existed”. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [November 10, 2024, 9:32pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/50 "2024-11-10T21:32:00Z")
> [@Mijin](#): > > Why _what_? No-one talked about infinite energy and it is not necessarily the case that there was such in the big bang. If the universe is infinitely large then it has infinite energy/mass by definition. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [November 10, 2024, 9:36pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/51 "2024-11-10T21:36:46Z")
Sure, but no-one asserted the universe is infinite, just asked the question. So it seems strange to me to ask _why_ at this point. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 10, 2024, 10:04pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/52 "2024-11-10T22:04:53Z")
Besides which, as anyone who’s ever associated with a three-year-old knows, it’s always possible to keep on asking “why”, no matter what other answers one already has. At some point, eventually one must run out of answers. ---
**Author:** ![Charlie\_Tan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/charlie_tan/32/12582_2.png) [@Charlie\_Tan](https://boards.straightdope.com/u/Charlie_Tan)\ **Post date:** [November 10, 2024, 10:07pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/53 "2024-11-10T22:07:35Z")
> [@Mijin](#): > > So it seems strange to me to ask _why_ at this point. Maybe. But why did it happen? And no, I’m not even remotely trying to get to some kind of deity. I’m blessed by being absolutely free of religion. I said ‘infinite energy’ because I can think of no other way a singularity without dimension can generate the immense vastness of the universe. But this is also why I’m asking. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [November 10, 2024, 10:33pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/54 "2024-11-10T22:33:15Z")
> [@DPRK](#): > > There are some classical results: > [general relativity - Can the universe's topology change during its evolution? - Physics Stack Exchange](https://physics.stackexchange.com/questions/662243/can-the-universes-topology-change-during-its-evolution) > > > There are some classic results showing, on Lorentzian spacetime, topology changes violate causality (Geroch proved this in the '60s) My question: is causality absolutely linear? If we can observe eventual vectors and anicipate a result, we adjust our behavior based upon the likely/inevitable event. The passage of time is a flow of information, which can identify future events in the present, so I have to wonder if causality vioation must be a deal breaker.   > [@Mijin](#): > > there are overarching questions of how/why anything exists at all, and those are definitely in the “we don’t know” column. At this time it looks intractable and all current answers, whether scientific or religious, boil down to “A thing just existed”. This was addressed in a book I read (cannot remember title or author) which involved reason murdering deities. The assertion was framed in the manner of nothing being in a perfect state of equillibrium, a state which is analogous to a bowling ball perfectly balanced on the tip of a spear: it is inherently unstable. Nothing diverged from its state in a natural way, thence becoming something. Nothing became something because that was the only possibility. Reality came to exist because it had to. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [November 10, 2024, 11:33pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/55 "2024-11-10T23:33:26Z")
> [@eschereal](#): > > This was addressed in a book I read (cannot remember title or author) which involved reason murdering deities. The assertion was framed in the manner of nothing being in a perfect state of equillibrium, a state which is analogous to a bowling ball perfectly balanced on the tip of a spear: it is inherently unstable. Nothing diverged from its state in a natural way, thence becoming something. Nothing became something because that was the only possibility. Reality came to exist because it had to. When you say “addressed” you mean a particular perspective was put forward, because personally I don’t think it gets us anywhere. We still have to start with some kind of status of there being nothing, and then that this state has a property of being in an unstable equilibrium. Then that equilibrium falls into a universe governed by consistent laws. To me it is accepting _more_ propositions than just taking the universe’s existence as the starting point. And personally, I leave it there. I don’t agree with the instinct, many seem to have, to say that this or that thing explains existence, or that the lack of an explanation _is itself_ the explanation. The real answer right now, IMO, is: _we don’t know_ why anything exists, and it looks intractable at the moment, as every answer just takes us down one turtle. That’s the state of play. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [November 11, 2024, 12:28am UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/56 "2024-11-11T00:28:25Z")
> [@eschereal](#): > > My question: is causality absolutely linear? If we can observe eventual vectors and anicipate a result, we adjust our behavior based upon the likely/inevitable event. The passage of time is a flow of information, which can identify future events in the present, so I have to wonder if causality vioation must be a deal breaker. Not speaking about that particular article, but in (very basic) quantum mechanics, the time-evolution operator must indeed be linear, and moreover unitary. That puts some constraints on causality violation. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [November 11, 2024, 4:58am UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/57 "2024-11-11T04:58:54Z")
> [@Mijin](#): > > We still have to start with some kind of status of there being nothing, and then that this state has a property of being in an unstable equilibrium. Genuine “nothing” is more a philosophical concept that is difficult to model. The author’s goal was to slay deities because, based on scriptural narratives and using a notion of “nothing” that is obtainable, it would natural collapse into something. A lot of physics is hard for ordinary people to understand: he was just framing a narrative to counter creation mythology. I think it has been said before that “the beginning” is not meaningful from the perspective of singularity. The Big Bang is simply a reachable way to make sense of the available data. > [@DPRK](#): > > Not speaking about that particular article, but in (very basic) quantum mechanics, the time-evolution operator must indeed be linear, and moreover unitary. The article I read initially is more than a decade old and has not gained muchtraction, but I found a fairly recent [essay](https://ar5iv.labs.arxiv.org/html/0812.3869) on arXiv which suggests that multiple time dimensions may possibly be brought in line with current theory. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [November 11, 2024, 6:25am UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/58 "2024-11-11T06:25:42Z")
In the normal Schroedinger equation, a particle’s state is a function of time. If there are supposed to be multiple time dimensions, what determines the time experienced by a particle? ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [November 11, 2024, 7:07am UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/59 "2024-11-11T07:07:57Z")
I do not pretend to comprehend multi-dimensional time or how it would work, but the linked essay said something to the effect that, to an observer, one of the time dimensions mostly looks like a space dimension, just with a negative sign with respect to motion. It would look like a slice spacetime that is not quite isotropic. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [November 11, 2024, 2:16pm UTC](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983/60 "2024-11-11T14:16:38Z")
> [@eschereal](#): > > Genuine “nothing” is more a philosophical concept that is difficult to model. The author’s goal was to slay deities because, based on scriptural narratives and using a notion of “nothing” that is obtainable, it would natural collapse into something. A lot of physics is hard for ordinary people to understand: he was just framing a narrative to counter creation mythology. Well I am speaking more of the philosophical question, as are I think, most people that raise it. To physicists it may be an important element of the story to figure out how the laws of physics could have led to the existence of space time from some state where neither such existed. In terms of the philosophical question though, as I say, we’ve just gone down a turtle. We have to posit a starting state (whether we use the word “nothing” in describing this state is irrelevant; the point is there are already infinite states that it _isn’t_, so a lane has been picked), and we also have to assume laws of physics from the get-go. So we may as well have just assumed a universe. This is normally the point in the conversation where someone will throw up their hands and say it is impossible; surely _any_ description needs to start somewhere. And that seems true; it’s why, at this time, it’s a question that appears intractable. I make no claim that it will always look that way to us though. [Previous page](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983.md?page=2) [Next page](https://boards.straightdope.com/t/was-the-universe-infinitely-large-immediately-after-the-big-bang/1008983.md?page=4)