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Our Universe wasn’t empty, even before the Big Bang

bigthink.com

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Re: Our Universe wasn’t empty, even before the Big Bang

#11

Post by philipov »

ravenstine wrote: post #4
fasterik wrote: post #2

>Even in the distant past, during the period of cosmic inflation that occurred before the Big Bang, that background radiation was present What does "before the Big Bang" mean? Don't space and time break down at the Big Bang singularity? Didn't cosmic inflation happen 10^-36 seconds after the Big Bang?

Yeah, it's hard to understand what that means because the furthest point back in time that we know of could be looked at as the beginning of the big bang, even if there was a delay of some kind before the most significant expansion.

I think they think the big bang means the moment the cosmic microwave background was created, and are confusing the big bang with recombination (which made the universe transparent). Why else would they suggest that inflation happened before the big bang?

Re: Our Universe wasn’t empty, even before the Big Bang

#14

Post by rm999 »

There's a lot of confusion in this thread about "before the big bang". I was also confused and did some googling and found this explanation from a professor of theoretical physics. It seems that it's actually pretty normal to refer to the big bang as happening after the initial inflationary epoch, but others refer to it as the moment before this.

>Do not allow yourself to be confused: The Hot Big Bang almost certainly did not begin at the earliest moments of the universe. Some people refer to the Hot Big Bang as “The Big Bang”. Others refer to the Big Bang as including earlier times as well. This issue of terminology is discussed at the end of this article on Inflation [https://profmattstrassler.com/articles-and-posts/relativity-...].

The article is talking about the "hot big bang", so it's using terminology that is accepted by other theoretical physicists.

https://profmattstrassler.com/articles-and-posts/relativity-...

Re: Our Universe wasn’t empty, even before the Big Bang

#15

Post by travisgriggs »

Lots of complaints here about how "before" somehow "crosses a line" and this isn't science any more. I guess I think it's more gradient than that. We're mad because this is "before", but just the other day, we had headlines indicating that ... may be ... the universe is 2x older than what I've been told for years. At this point, I'm totally with Nate Bargatze on this stuff:

https://youtu.be/lkCvP4jttHI

Re: Our Universe wasn’t empty, even before the Big Bang

#16

Post by edgyquant »

ravenstine wrote: post #4
fasterik wrote: post #2

>Even in the distant past, during the period of cosmic inflation that occurred before the Big Bang, that background radiation was present What does "before the Big Bang" mean? Don't space and time break down at the Big Bang singularity? Didn't cosmic inflation happen 10^-36 seconds after the Big Bang?

Yeah, it's hard to understand what that means because the furthest point back in time that we know of could be looked at as the beginning of the big bang, even if there was a delay of some kind before the most significant expansion.

I really don’t think it’s hard and basically everyone knows what is meant by this. Physicists just like to be pedantic about the technicalities of what “before” means.

Re: Our Universe wasn’t empty, even before the Big Bang

#17

Post by teucris »

The title is terrible and doesn’t refer to the actually interesting key point in the article!

The idea trying to be expressed is actually that the expansion of the universe is releasing energy, making the concept of “empty” space impossible as even the emptiest areas are still emitting energy.

Re: Our Universe wasn’t empty, even before the Big Bang

#18

Post by philsquared_ »

RcouF1uZ4gsC wrote: post #5

Anything thing that talks about "Before the Big Bang" isn't science. It may be philosophy or mathematical speculation, but it is not science.

"Anything that talks about 'the world is round' isn't science. It may be astrology or mathematical speculation but it is not science."

Re: Our Universe wasn’t empty, even before the Big Bang

#19

Post by MattPalmer1086 »

digging wrote: post #9

This article doesn't make any sense. Skimming over it, I don't see that it's even about "before the Big Bang," which is a nonsense phrase. Nor do I see why it's arguing the point that our universe has even been empty, because nobody has ever argued that it was. Ah, it's talking about the future, when it might be "empty", and explaining to the reader how it won't actually be empty. That's weird. Ah, it's now circling…

The big bang has two meanings in common usage. Some people think it means "the beginning of time". But it can also refer to the time immediately after inflation. [1]

[1] https://profmattstrassler.com/articles-and-posts/relativity-...

Re: Our Universe wasn’t empty, even before the Big Bang

#20

Post by wredue »

digging wrote: post #9

This article doesn't make any sense. Skimming over it, I don't see that it's even about "before the Big Bang," which is a nonsense phrase. Nor do I see why it's arguing the point that our universe has even been empty, because nobody has ever argued that it was. Ah, it's talking about the future, when it might be "empty", and explaining to the reader how it won't actually be empty. That's weird. Ah, it's now circling…

Some physicists disagree with Hawking.

The assertions in the article don’t seem to make a strong case for talking about “before”, but that doesn’t make Hawking definitely right either.

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