B Anything from Nothing: Uncovering the Possibilities

[RajeshR]

If something from nothing is true then "anything" can come from nothing .. What is stopping it ?
For all we know a totally different universe could have come from nothing or a Dragon or Sentient being could have come from nothing.

In short are there any theories to why only "this something" came from nothing. Why not anything else from nothing?

 

[timmdeeg]

Physics doesn't deal with "something from nothing". It deals with "something" (e.g. something is the present state of the universe) from "something else" (eg. the hot and dense state of the early universe). In other words, physical theories don't deal with creation of something per se.

 

[bhobba]

If something from nothing is true then "anything" can come from nothing .. What is stopping it ?

Where are you getting this idea physics says something comes from nothing?

The modern theories I am aware of says the universe comes the false vacuum and inflation.
https://en.wikipedia.org/wiki/False_vacuum

Thanks
Bill

 

[phinds]

Where are you getting this idea physics says something comes from nothing?

He's probably been reading Lawrence Krauss's "A Universe From Nothing".

 

[ZapperZ]

If something from nothing is true then "anything" can come from nothing .. What is stopping it ?
For all we know a totally different universe could have come from nothing or a Dragon or Sentient being could have come from nothing.

In short are there any theories to why only "this something" came from nothing. Why not anything else from nothing?

Since you never clarified, I will assume that you want a "pedestrian" answer to such a question, rather than the deep, mathematical description of the physics behind such a thing.

Coincidentally, a couple of days ago, an article by Ethan Siegel on a simple summary of the scientific meanings of "nothing" was published. I suggest you start your inquiry from there.

Zz.

 

[anorlunda]

a couple of days ago, an article by Ethan Siegel on a simple summary of the scientific meanings of "nothing" was published.

Zz.

Wow, thank you for the link Zz. It made a enjoyable read. It reminded me of Feynman's famous verbal essay on "why" questions.

 

[ZapperZ]

Wow, thank you for the link Zz. It made a enjoyable read. It reminded me of Feynman's famous verbal essay on "why" questions.

You're welcome. Ethan Siegel has posted on Forbes many other easy-to-read articles for the general public.

Now, the question is whether the OP will actually come back and learn something from all the responses to the question, or is this another post-and-run thing.

Zz.

 

[Arman777]

If something from nothing is true then "anything" can come from nothing .. What is stopping it ?

The universe could have been evolved much different way than ours. For example, we don't know why the nature constants have these particular values. If they were different the universe would be different.

In short are there any theories to why only "this something" came from nothing. Why not anything else from nothing?

We don't know and we can't know.

But you can try to look the situation, from the anthropic principle perspective.

I think nothingness is more of a philosophical idea. It's not something "physical" that we can measure, observe or understand.

The modern theories I am aware of says the universe comes the false vacuum and inflation.

The inflation is where the universe "comes from"? Or it's just a era in the history of the universe?

 

[Arman777]

The inflation is where the universe "comes from"? Or it's just a era in the history of the universe?

I'll quote myself

The inflation didn't create the universe" but "it led to creating the universe as we currently know".

Inflation happened $10^{-35}$ second after the Big Bang singularity and we know that singularity doesn't belong to any point in space-time hence I think we can say that in the period between the BBS and cosmic inflation there was a false vacuum. At $t=10^{-35}$ cosmic inflation happened and then we know the rest.
(In here I considered slow roll inflation theory. There are of course other theories for inflation)

Cosmic inflation is just an era in the universe. We can think the universe before the inflation but after the Big Bang singularity.

 

[PeterDonis]

Inflation happened $10^{-35}$ second after the Big Bang singularity

This is not a good way of putting it, because "the Big Bang singularity" is not an actual event, it's an artifact of a particular model. Which, btw, is not even the inflationary model. Basically, what times like that mean, when they appear in a description of cosmological models, is: take the temperature of the universe at some particular event of interest (in this case, the end of inflation, when reheating is completed); take an idealized FRW model which does not include inflation, and figure out at what time after the initial singularity the universe had that temperature; then give that time as the "time" of the event of interest.

Personally, I would rather that cosmologists just gave temperatures directly, instead of trying to convert them to times using a model that isn't even the right one. But that is the common custom.

 

[Arman777]

Which, btw, is not even the inflationary model.

What's this means?

I see your point since the reheating happens the temperature of the universe would be the approximately same after and before the inflation.

Personally, I would rather that cosmologists just gave temperatures directly, instead of trying to convert them to times using a model that isn't even the right one. But that is the common custom.

But don't you think we need time or time interval to understand where the inflation started and ended? Since as you said If I just say it happened at $10^{27}$ K there will be confusion about, Is it the end of inflation ? or the beginning of the inflation?

 

[PeterDonis]

What's this means?

Just what I said, and described in my previous post. The model from which times like $10^{-35}$ second come from is not the actual inflationary model cosmologists are using. It's an idealized non-inflating FRW model. The correspondence between the two models, that is used to get the times cosmologists give, is done using temperature.

The actual inflationary model cosmologists are using doesn't even have an "initial singularity" in it at all. We don't know whether there was such a thing or not; in some inflationary models (the "eternal inflation" ones), the universe has no beginning, it extends infinitely far backward in time. Currently we don't have any way of testing which models are correct, so our current best-fit model makes no commitment on whether there was an initial singularity or not; it simply goes no further back than the beginning of inflation.

since the reheating happens the temperature of the universe would be the approximately same after and before the inflation.

I think you mean after and before the reheating? That is not the case: before reheating, there was a huge potential energy stored in the inflaton field, which had zero temperature (it was in a "false vacuum" state). After reheating, all of that energy is now in the Standard Model fields, which are therefore at very high temperature (because there is no "false vacuum" state for them, whatever energy they have is kinetic energy and must show up as temperature, at least under the conditions right after reheating, when all of the SM fields are massless).

don't you think we need time or time interval to understand where the inflation started and ended?

If we do, then cosmologists aren't telling us what the actual time or time interval was. See above.

If I just say it happened at $10^{27} K$ there will be confusion about, Is it the end of inflation ? or the beginning of the inflation?

The way to fix that is easy: just say which.

 

[Arman777]

I understand it now, thanks!

 

[AgentSmith]

You can't even define nothing, so something from nothing is meaningless. Not false, meaningless. Despite this some top physicists still use the term in popular literature. It sells books.

 

[cave man]

Does all this really mean that there really never was "nothing". Is the Cosmos a never beginning and never ending existence? Is there any proof to this? Or is everything on this topic speculation?

 

[nikkkom]

What's this means?

I see your point since the reheating happens the temperature of the universe would be the approximately same after and before the inflation.

We don't even know whether "before the inflation" existed. I, for one, like eternal inflation models, where most of the Universe is in false vacuum state and inflating all the time, and was inflating in the past for unknown, possibly infinitely long time. True vacuum patches (like ours, containing observable Universe) are actually an exception, a very small fraction of the volume.

 

[Arman777]

We don't even know whether "before the inflation" existed.

Yes, I am aware of that.

The actual inflationary model cosmologists are using doesn't even have an "initial singularity" in it at all. We don't know whether there was such a thing or not; in some inflationary models (the "eternal inflation" ones), the universe has no beginning, it extends infinitely far backward in time.

PeterDonis also said it.

 

[Arman777]

Does all this really mean that there really never was "nothing". Is the Cosmos a never beginning and never ending existence? Is there any proof to this? Or is everything on this topic speculation?

I think it's just metaphysics.

 

[Arman777]

You can't even define nothing,

Can we define nothing as an empty set where S={ } ?

 

[phinds]

Can we define nothing as an empty set where S={ } ?

That's math, not physics.

 

[Arman777]

That's math, not physics.

Indeed but mathematically we can define.

 

[cave man]

I think it's just metaphysics.

"Whatever is is and cannot no be". "Matter cannot be created nor destroyed".
But, was it always thus? If entropy will be the end of our universe, will energy always be present?
Can a dimension disappear, while others thrive? I think that metaphysics studies what is, but not what was or will be.

 

[PeterDonis]

mathematically we can define

Sure, but how do you match up the math to experiments? Suppose we say that the state of the universe is the empty set. What experimental predictions does that translate to?

 

[cave man]

Can physics define what was or will be? I think outcomes can known from physics as well as understanding events in the past. But there seems to be a limit to what physics can conclude with certainty. Mathematics has the same restriction. Until verified conclusively as a reality that is observable, neither can present what did happen as well as what will happen if it passes the limits of the possibility of that which is observable. For instance,
the computer chip in cars that regulates data that it is given, as well as sending messages to what it controls, has to be tested and proven reliable after being programed and connected to controls in the car.

 

[phinds]

"Matter cannot be created nor destroyed".

Matter is routinely created and destroyed in particle accelerators like the LHC.

 

[Arman777]

Sure, but how do you match up the math to experiments? Suppose we say that the state of the universe is the empty set. What experimental predictions does that translate to?

Well I can't match up with the experiment...

Also I said earlier that,

Can we define nothing as an empty set where S={ } ?

But I find that "The empty set is not the same thing as nothing; rather, it is a set with nothing inside it and a set is always something." which makes sense.

https://en.wikipedia.org/wiki/Set_(mathematics) (its a wiki qoute but the idea makes sense)

You can't even define nothing,

You are right.

 

[phinds]

... there seems to be a limit to what physics can conclude with certainty. Mathematics has the same restriction.

No, mathematics has no such restriction. As long as it is internally consistent, math is certain.

 

[PeterDonis]

I can't match up with the experiment

Then it's off topic here. You can discuss set theory in the math forum.

 

[trainman2001]

Am I correct in understanding that subatomic particles come in and out of existence randomly? In that case, is something coming from nothing?

 

[phinds]

Am I correct in understanding that subatomic particles come in and out of existence randomly? In that case, is something coming from nothing?

No, these "virtual particles" that you may have read about are a mathematical fiction, not real.
https://www.physicsforums.com/insights/misconceptions-virtual-particles/

 

[Enty]

Unfortunately, we can never be sure of nothing. Even if we did appear to perceive something from nothing we could not be certain that our something didn't arise from some other thing that resided within that nothing of which we have no concept.

Then there's the little problem that even if there were nothing unless everything were nothing, nothings would have a boundary and as, by definition, nothing could cross that boundary we could never have an awareness of what lay within the boundary. Consequently even if we perceive what appears to us to be something from nothing what we have really observed is the appearance of something from a boundary which may or may not have encapsulated nothing.

'When I make a word do a lot of work like that,' said Humpty Dumpty, 'I always pay it extra.'

 

[phinds]

Unfortunately, we can never be sure of nothing. Even if we did appear to perceive something from nothing we could not be certain that our something didn't arise from some other thing that resided within that nothing of which we have no concept.

Then there's the little problem that even if there were nothing unless everything were nothing, nothings would have a boundary and as, by definition, nothing could cross that boundary we could never have an awareness of what lay within the boundary. Consequently even if we perceive what appears to us to be something from nothing what we have really observed is the appearance of something from a boundary which may or may not have encapsulated nothing.

I recognize every single word in that post, but strung together in that particular order, I can't make any sense out of them at all.

 

[Vanadium 50]

Certain that our something that our something didn't nothing. Even if we what appears to us not have encapsulated nothing. Appears to us to a boundary which may could cross that boundary that even if there the appearance of something there were nothing unless to us to be there were nothing unless certain that our something we could never have we can never be and as, by definition, could cross that boundary what appears to us we did appear to we have really observed sure of nothing. Even something from nothing what what we have really of what lay within little problem that even of what lay within were nothing unless everything even if we perceive some other thing that sure of nothing. Even from a boundary which nothing unless everything were to perceive something from the boundary. Consequently even were nothing unless everything is the appearance of have an awareness of sure of nothing. Even nothing of which we as, by definition, nothing were nothing, nothings would did appear to perceive Unfortunately, we can never what lay within the Consequently even if we we can never be didn't arise from some nothing of which we to us to be of which we have not be certain that from nothing what we nothing we could not can never be sure would have a boundary and as, by definition, within the boundary. Consequently may or may not resided within that nothing boundary which may or we can never be something didn't arise from that even if there perceive something from nothing something from a boundary have really observed is can never be sure nothing could cross that appearance of something from which we have no something from nothing we little problem that even even if there were something from nothing we we did appear to nothing we could not nothing we could not nothing of which we unless everything were nothing.

 

[phinds]

Certain that our something ...

Yeah. What he said.

 

[PhanthomJay]

...unless everything were nothing.

Now that makes sense!

 

[Vishal Rana]

If something from nothing is true then "anything" can come from nothing .. What is stopping it ?
For all we know a totally different universe could have come from nothing or a Dragon or Sentient being could have come from nothing.

In short are there any theories to why only "this something" came from nothing. Why not anything else from nothing?

I think the word “nothing” is throwing you off. It threw me off I thought “how can something come from absolutely nothing?” There has to be something there obviously I’m assuming the “nothing” is referring to the unknown, something we don’t yet know. I know physics is weird but in the way I think, there has to be something to create something or does that not violate the conversation of energy law? Unless the “nothing” we thing “something” is coming from is actually coming from another dimension? Hence why a 2D creature wouldn’t be able to comprehend an object they see entering the 3rd dimension, for them it disappeared. The same should apply to us surely.

 

[phinds]

I think the word “nothing” is throwing you off...

You should have stopped right there.

 

[Vishal Rana]

You should have stopped right there.

Why

 

[phinds]

Why

Because arguments about what "nothing" is always go nowhere. You've also gone off into a mythical "other dimension" as a possible solution. AND you require conservation of energy in a regime in which it is not known if that applies (as it does not apply, for example, over cosmological distances).

 

[Vishal Rana]

Because arguments about what "nothing" is always go nowhere. You've also gone off into a mythical "other dimension" as a possible solution. AND you require conservation of energy in a regime in which it is not known if that applies (as it does not apply, for example, over cosmological distances).

But is the other dimension really a myth tho?

 

[Ibix]

But is the other dimension really a myth tho?

Yes. If you think otherwise, please provide an appropriate peer-reviewed reference discussing the topic - this is the minimum standard for an idea to be discussed on PF.

Note that I am aware that spacetime is usually modeled as four dimensional, but there is no time where a spacelike slice of it qualifies as "nothing". So references discussing general relativity are not sufficient. Also, some theories like Kaluza-Klein theory and string theory add further dimensions on top of the usual four. Again, these are not nothing and are not part of an explanation for the origin of the universe, so are not sufficient either.

 

[PeterDonis]

This seems like a good place to close this thread.