Why Stephen Hawking says universe can create itself from nothing?

[big_bounce]

Hello all .
I can not explain good but hope you will understand my purpose .

I read in University Oregon's website that universe came from a pure energy in vacuum
If we want to say exactly , we can say universe came from Potential energy in vacuum .

We know in physics there are some conversation laws such as conversation of energy and conversation of angular and linear momentum and son on .

And we know momentum is a quantity that can carry by objects and particles like electrons and photons and in generally any elementary particles .

And we know in early universe there aren't any particles or objects just existed pure energy .

And we know energy isn't physical object or particle .

My first question is :

1 -Was there in early universe any momentum ? conversation of momentum says it should be existed ( like energy ) but this momentum carry by what (or which ) particles or objects ?


My second question is :
2 - energy is thing or nothing ? why Stephen Hawking says universe came from nothing ? if we consider universe came from pure energy .


My third question is :
3- why we can not say universe came from pure momentum ? why we must say universe came from pure energy ?


I really confused .

Thanks for your help .

 

[Drmarshall]

Hello all .
I can not explain good but hope you will understand my purpose .

I read in University Oregon's website that universe comes from a pure energy in vacuum
If we want to say exactly , we can say universe comes from Potential energy in vacuum .

We know in physics there are some conversation laws such as conversation of energy and conversation of angular and linear momentum and son on .

And we know momentum is a quantity that can carry by objects and particles like electrons and photons and in generally any elementary particles .

And we know in early universe there aren't any particles or objects just existed pure energy .

And we know energy isn't physical object or particle .

My first question is :

1 -Was there in early universe any momentum ? conversation of momentum says it should be existed ( like energy ) but this momentum carry by what (or which ) particles or objects ?


My second question is :
2 - energy is thing or nothing ? why Stephen Hawking says universe comes from nothing ? if we consider universe comes from pure energy .


My third question is :
3- why we can not say universe comes from pure momentum ? why we must say universe come from pure energy ?


I really confused .

Thanks for your help .

Yes, momentum. But how "early" do you want to go?

Energy is a mere concept. A useful idea if the only brain you have is a poor human one

We cannot say "came from" because if so that would be "before the beginning"

 

[MathematicalPhysicist]

You should really not listen to this nonsense.

I don't care how intelligent Stephen is, nothing can be created from nothing, so does he posit that we are actually really just nothing?

 

[Mordred]

The universe from nothing model isn't quite as crazy as you might think. A lot of top level cosmologists feel that it is a strong possibility.
Here is a quick guideline on process.
Key point in order for this model to work is that energy density must balance with zero energy. Gravity being considered as negative energy.
Rapid expansion occurs this creates a false vacuum. This false vaccuum. To maintain energy conservation energy is borrowed. I can't recall what the model states its borrowed from but if I recall its borrowed from gravity.
With that energy quantum tunneling occurs from virtual particles. Some of the virtual particles tunnel to the true vacuum. Leaving real particles.

It should be noted that virtual particles are created in a large variety of sources. Cosmological horizons. =Unruh radiation. Blackholes is Hawking radiation. Schwinger particle production is electromagnetic disturbences. Parker radiation is due to expansion.
All of the above are various blackbody radiation.

There are countless other particle production methods.
What they all boil down to is a vacuum is never empty.
False vacuum being the lowest energy state has quantum fluctuations described by Heisenburg uncertainty principle. Those fluctuations in turn create virtual particles. Those virtual particles in the right circumstances become real particles.
Throughout out all this for this model the energy density must stay equal to zero with gravity and vacuum energy as part of the balancers.
However even if the energy density isn't zero the various particle production methods describe above are all still valid.
Sounds crazy however their is tons of research and models that support this ultimate free lunch.

 

[Mordred]

Here is a link to a description of false vacuum.
http://ned.ipac.caltech.edu/level5/Guth/Guth3.html

if your interested in some of the other particle producers I can post some decent articles on them

 

[Chalnoth]

You should really not listen to this nonsense.

I don't care how intelligent Stephen is, nothing can be created from nothing,

Why not?

 

[MathematicalPhysicist]

Cause to create something from nothing you need to do something illogical, magical, mystical.

And that's the break of rationality, it's possible, but then I might as well also believe in witches and fairies.

 

[Crazymechanic]

I'm afraid it has been always like this, when something large is about to reveal itself the majority can't believe their eyes.
Imagine the first light bulb or the fact that most of the scientists at the time believed that nothing heavier than air could fly.
Ok I understand this is a much bigger issue here that were facing not comparable to some jumbo jets or light bulbs but if it exists and if we exist then there was a way it started we may not understand or have access to that way but that doesn't make the way it went less real or possible.

 

[Chalnoth]

Cause to create something from nothing you need to do something illogical, magical, mystical.

Prove it.

 

[Johninch]

Cause to create something from nothing you need to do something illogical, magical, mystical.

First, leaving aside the creation activity, you can have a positive and a negative which compensate to zero. Both exist. It depends then what you mean by something and nothing.

Secondly, creation is going on all the time in so called empty space, with matter and antimatter particles anihilating each other.

So putting the two together, we can easily have creation from nothing.

"You" don't have to do anything, if creation is an automatic and therefore inevitable process.

.

 

[phinds]

Lawrence Krause has a whole book about this, "A Universe from Nothing", in which he supports this theory.

 

[Mordred]

The reaction your having is a coomon problem. However its one that stems from lack of knowledge in current cosmology. Not everything in science is easily understood by common sense. quantum entanglement is another that defies common sense.

With that in mind Can you show another model that expains how everything can develop? In cyclic models how did the first universe start?
Same applies to commoving models.
The one advantage this model presents is its lack of needing an outside source.
However the OP did not ask for personal opinions.
His post wanted an understanding of Hawking statement. That has been provided personal opinions aside

 

[julcab12]

First, leaving aside the creation activity, you can have a positive and a negative which compensate to zero. Both exist. It depends then what you mean by something and nothing.

Secondly, creation is going on all the time in so called empty space, with matter and antimatter particles anihilating each other.

So putting the two together, we can easily have creation from nothing.

"You" don't have to do anything, if creation is an automatic and therefore inevitable process.

.

So far in all our efforts 'nothing' always amount to something. It only make sense if you put constraints on nothing(vacuum/false vacuum/empty space)".

 

[rbj]

Cause to create something from nothing you need to do something illogical, magical, mystical.

And that's the break of rationality, it's possible, but then I might as well also believe in witches and fairies.

Prove it.

where should the burden of proof be? that nothing comes from nothing? or that something comes from nothing? why should the burden of proof be on the former rather than the latter?

 

[Chalnoth]

where should the burden of proof be? that nothing comes from nothing? or that something comes from nothing? why should the burden of proof be on the former rather than the latter?

He made a positive statement: it is impossible to create something from nothing. I asked him to back that statement up with more than ridicule.

The default should always be, "We don't know." If somebody had stated, "The universe was created from nothing in this specific way," then that would be a statement requiring evidential support. MathematicalPhysicist made a much, much stronger statement: that there is no possible way that something can come from nothing. That statement requires a mathematical proof as support.

 

[rbj]

Lawrence Krause has a whole book about this, "A Universe from Nothing", in which he supports this theory.

for those of us that don't have the book and don't expect to order it, might you summarize the best argument for this notion? i would be quite interested.

i remember listening to Michael Schermer about it, and he said "maybe something is a more stable state than nothing."

it sounded like it was kinda an appeal to the notion that the big bang was a humongous quantum fluctuation. instead of an electron or some other sub-atomic particle just appearing or disappearing somewhere due to the nature of QM, a whole primordial universe just pops into existence 13.7 billion years ago.

 

[rbj]

He made a positive statement: it is impossible to create something from nothing. I asked him to back that statement up with more than ridicule.

okay, so i'll turn it around to this positive statement: "The Universe we observe created itself from nothing approximately 13.7 billion years ago."

why should the burden of proof be applied to the contrary rather to this positive statement?

The default should always be, "We don't know."

boy, am i glad to read you say that.

... That statement requires a mathematical proof as support.

this requires more than "mathematical proof". again (from the other thread), the mathematical relationships we call "physical law" describe the interaction of "stuff". the math is not the "stuff". and "stuff" is not "nothing".

 

[Naty1]

my third question is :
3- why we can not say universe came from pure momentum ? why we must say universe came from pure energy ?

I'm no expert on quantum theory, but I have not seen momentum ascribed to vacuum energy.

Vacuum energy:

...The theory considers vacuum to implicitly have the same properties as a particle, such as spin or polarization in the case of light, energy, and so on. According to the theory, most of these properties cancel out on average leaving the vacuum empty in the literal sense of the word. One important exception, however, is the vacuum energy or the vacuum expectation value of the energy.

http://en.wikipedia.org/wiki/Vacuum_energy

Another way to think about this is to consider potential energy...energy without momentum AFAIK.

The zero point energy, vacuum energy, false vacuum, vacuum expectation value, call it what you will, all are related to the potential energy of the Hamiltonian formalism and to the Heisenberg uncertainty principle...that is, quantum jitters or uncertainty...

 

[Chalnoth]

this requires more than "mathematical proof". again (from the other thread), the mathematical relationships we call "physical law" describe the interaction of "stuff". the math is not the "stuff". and "stuff" is not "nothing".

But when you say something is impossible, that requires a mathematical proof. That proof may be based upon specific assumptions that are grounded in evidence, but it requires proof nonetheless.

Anyway, I'll just put forward that it cannot be done, because the very concept of 'nothing' isn't a well-defined concept in the first place. Somebody could put forward a model that claims to be a start of the universe from nothing, and the other person can simply respond, "But that's not what I meant by nothing!" So in the end, arguing about whether or not the universe could have started from nothing is both a ridiculous and unhelpful line of argument.

Things get much more interesting when we start to consider actual models for generating our observable universe. Then there's actually a sensible conversation to be had, where things aren't necessarily bound to devolve into a useless argument over the definition of 'nothing'.

For example, it seems quite likely, given current evidence, that our observable universe started with a period of inflation. During inflation, our entire observable universe (and much that lies beyond it) came from a small inflating patch that need not have been any larger than a proton.

This suggests an interesting possibility: what if our universe began with a microscopic quantum vacuum fluctuation? That is, previous to the start of our universe, there might have been some other universe which was mostly empty (as ours will be in the far future). Such a vacuum isn't completely inert: it tends to bubble and froth with quantum mechanical particles. Perhaps one of those bubbles was just right to get inflation started, creating a new universe (ours).

From outside this bubble, it would look like a microscopic black hole had popped into existence, then quickly decayed. From the inside, we have a whole universe. The physical process can be sort of visualized by imagining that the parent universe is sort of a membrane that tends to wiggle all the time. At some point one of these wiggles got exceptionally large and sharp, and pinched off a little bubble. That bubble, now disconnected from the parent universe, grew on its own to become a large universe in its own right.

This, of course, is a picture of how our universe might have started from some other. It can be said to have started from nothing in the sense that it started from a previous vacuum state, even if some might argue that that wasn't really nothing. But whichever way you slice it, it is a way to generate new regions of space-time by a dumb, purposeless physical process. And that I find interesting.

Now, it is conceivable that somebody might come up with a way to describe a universe's beginning without there being anything before (no space-time, no matter, nothing), but that comes with a significant problem: how do you describe 'nothing' mathematically? This doesn't mean it's impossible, but it does mean that we can't really start to examine the possibility without a coherent description of what 'nothing' actually means.

 

[MathematicalPhysicist]

He made a positive statement: it is impossible to create something from nothing. I asked him to back that statement up with more than ridicule.

The default should always be, "We don't know." If somebody had stated, "The universe was created from nothing in this specific way," then that would be a statement requiring evidential support. MathematicalPhysicist made a much, much stronger statement: that there is no possible way that something can come from nothing. That statement requires a mathematical proof as support.

That's really simple.

If you create something from nothing then that nothing becomes something, cause if it were nothing then how did we got something?

As I said it's not logical, and we might as well start believe in witches and fairies if that's what we come to believe.

 

[big_bounce]

But when you say something is impossible, that requires a mathematical proof. That proof may be based upon specific assumptions that are grounded in evidence, but it requires proof nonetheless.

Anyway, I'll just put forward that it cannot be done, because the very concept of 'nothing' isn't a well-defined concept in the first place. Somebody could put forward a model that claims to be a start of the universe from nothing, and the other person can simply respond, "But that's not what I meant by nothing!" So in the end, arguing about whether or not the universe could have started from nothing is both a ridiculous and unhelpful line of argument.

Things get much more interesting when we start to consider actual models for generating our observable universe. Then there's actually a sensible conversation to be had, where things aren't necessarily bound to devolve into a useless argument over the definition of 'nothing'.

For example, it seems quite likely, given current evidence, that our observable universe started with a period of inflation. During inflation, our entire observable universe (and much that lies beyond it) came from a small inflating patch that need not have been any larger than a proton.

This suggests an interesting possibility: what if our universe began with a microscopic quantum vacuum fluctuation? That is, previous to the start of our universe, there might have been some other universe which was mostly empty (as ours will be in the far future). Such a vacuum isn't completely inert: it tends to bubble and froth with quantum mechanical particles. Perhaps one of those bubbles was just right to get inflation started, creating a new universe (ours).

From outside this bubble, it would look like a microscopic black hole had popped into existence, then quickly decayed. From the inside, we have a whole universe. The physical process can be sort of visualized by imagining that the parent universe is sort of a membrane that tends to wiggle all the time. At some point one of these wiggles got exceptionally large and sharp, and pinched off a little bubble. That bubble, now disconnected from the parent universe, grew on its own to become a large universe in its own right.

This, of course, is a picture of how our universe might have started from some other. It can be said to have started from nothing in the sense that it started from a previous vacuum state, even if some might argue that that wasn't really nothing. But whichever way you slice it, it is a way to generate new regions of space-time by a dumb, purposeless physical process. And that I find interesting.

Now, it is conceivable that somebody might come up with a way to describe a universe's beginning without there being anything before (no space-time, no matter, nothing), but that comes with a significant problem: how do you describe 'nothing' mathematically? This doesn't mean it's impossible, but it does mean that we can't really start to examine the possibility without a coherent description of what 'nothing' actually means.

It was a very good explanation .
Thanks

That's really simple.

If you create something from nothing then that nothing becomes something, cause if it were nothing then how did we got something?

As I said it's not logical, and we might as well start believe in witches and fairies if that's what we come to believe.

Somethings are not clear for me .
Universe is made of energy + momentum + charge + spin + elementary particles + dark matter + dark energy and so on .
When we say universe came from pure vacuum energy is that mean there was nothing except energy .

So do you say "momentum" and "spin" and "charge" and "elementary particles" and "dark matter" came from energy ? And energy is fundamental "stuff" that other things like elementary particles and momentum made of it ?
Can you prove that ?

 

[big_bounce]

I meant ,
Since there was nothing except energy and we know elementary particles are not energy , so universe and elementary particles came from nothing .

 

[DennisN]

Adding to what Chalnoth said, I just want to stress that the terms "nothing" and "something" are not physics terms as such. They are words used to gain attention in e.g. document titles and such. Also good for sparking debates. "Nothing" in this sense obviously don't mean "nothing at all", at least that's the way I interpret it.

 

[marcus]

I meant ,
Since there was nothing except energy and we know elementary particles are not energy , so universe and elementary particles came from nothing .

Surely you don't believe that though. So aren't you just beating a dead speculation---I mean a speculation that has gone out of style with the actual researchers: the professionals who, today, are actually engaged in early universe quantum cosmology.

Here's search for QC papers that have appeared since 2009:
http://inspirehep.net/search?ln=en&...=&d2m=&d2y=2013&sf=&so=a&rm=&rg=50&sc=0&of=hb

You can see what the dominant ideas are---not "creation from nothing"

It's even clearer if have the search sorted by cite-count, so that it lists the most highly cited papers first:
http://inspirehep.net/search?ln=en&...2y=2013&sf=&so=a&rm=citation&rg=50&sc=0&of=hb

So why should we be talking about some scenario that Stephen Hawking thought up 10 or 20 years ago?

 

[phinds]

for those of us that don't have the book and don't expect to order it, might you summarize the best argument for this notion? i would be quite interested.

i remember listening to Michael Schermer about it, and he said "maybe something is a more stable state than nothing."

it sounded like it was kinda an appeal to the notion that the big bang was a humongous quantum fluctuation. instead of an electron or some other sub-atomic particle just appearing or disappearing somewhere due to the nature of QM, a whole primordial universe just pops into existence 13.7 billion years ago.

Yeah, Kraus basically argues that quantum fluctuation(s) happened in a zero-net-energy space and this HAD to happen.

EDIT: the book is copyright 2012, so it's not the 10 or 20 years ago that Marcus noted Hawking as having propounded it.

By the way, I'm NOT arguing for or against the "something from nothing" theory, just presenting information (as opposed to shouting opinions which some of the thread seems to be about)

 

[marcus]

Mass market book, though. There is a divide between pop-sci discourse and what the actual professional research literature is about.
Try the link I gave and see if you find Larry Krauss' ideas are prevalent in those papers.
http://inspirehep.net/search?ln=en&...2y=2013&sf=&so=a&rm=citation&rg=50&sc=0&of=hb
The search currently gets 456 quantum cosmology papers (that appeared since 2009).
Bounce cosmology papers predominate.

This doesn't prove anything is RIGHT. Simply that Hawking speculation from 20 years ago does not interest people doing actual research.

At least among people who do quantum cosmology, the "create itself from nothing" has gone out of fashion on the professional side of the divide.

But it still fires the popular imagination and it continues to sell mass market books. Primarily I just want to note the contrast.

 

[phinds]

... speculation that has gone out of style with the actual researchers ...

Glad to hear this. I never did like the something from nothing argument, especially from Kraus because he drags the many-worlds theory in along with it.

EDIT: our posts crossed in the aether

 

[Mordred]

The original inflation model was taken up and adapted by several different personages.
One of the more recent was Alan Guth

Eternal inflation and its implications.
http://arxiv.org/pdf/hep-th/0702178v1.pdf

so the although the model originated a while ago its still relatively current. Athough their have been several corrections from its original. One of the problems with the original was runaway expansion that did not fit the data observed.

this is cut and paste from this article

The history of this subject has become a bit controversial, so I’ll describe my
best understanding of the situation. The idea that quantum fluctuations could be
responsible for the large scale structure of the universe goes back at least as far
as Sakharov’s 1965 paper [10], and it was re-introduced in the modern context by
Mukhanov and Chibisov [11, 12], who considered the density perturbations arising
during inflation of the Starobinsky [4] type. The calculations for “new” inflation,
including a description of the evolution of the perturbations through “horizon exit,”
reheating, and “horizon reentry,” were first carried out in a series of papers [13–16]
arising from the Nuffield Workshop in Cambridge, UK, in 1982. For Starobinsky
inflation, the evolution of the conformally flat perturbations during inflation (as
described in Ref. [12]) into the post-inflation nonconformal perturbations was
calculated

 

[marcus]

When inflation was first proposed, folks couldn't think of what might have caused it so they came up with all sorts of ideas like "quantum fluctuation" and "eternal" and "anthropic" (to explain why a quantum fluctuation would produce the right amount of inflation which would then conveniently stop). It was a large exercise of the imagination, which is certainly fine up to a point.
Guth strikes me as coming from an earlier era. But maybe he defines inflation for the general pubic. A lot has changed though. Guth, Hawking, Vilenkin, Linde don't write so much any more, or their papers don't get quite the same amount of attention. Here are some recent papers where inflation comes from *something*. There's growing interest in this (which again does not prove it's right.)

http://arxiv.org/abs/1301.1264
Inflation as a prediction of loop quantum cosmology

http://arxiv.org/abs/1302.0254
The pre-inflationary dynamics of loop quantum cosmology: Confronting quantum gravity with observations

http://arxiv.org/abs/1209.1609
A Quantum Gravity Extension of the Inflationary Scenario

http://arxiv.org/abs/1103.2475
Probability of Inflation in Loop Quantum Cosmology

http://arxiv.org/abs/0912.4093
Loop quantum cosmology and slow roll inflation

 

[Mordred]

I definitely agree that a lot has changed, I wouldn't be surprised to see that False vacuum base models however the name is defined still kicking around. The original model has been taken up and developed into a variety of models. String theory has also been playing around with it from what I could tell from some of the history searches I've done.
I'm actually surprised that the confirmation of the higgs boson hasn't caused a relook at the false vacuum idea as the Higgs field is one of the requirements.
Well for that matter it very well may have under some othere unrelated name lol.
I've read papers that utilize false vacuum in some supersymmetry articles but am unsure if that is the same type of false vacuum as described by these models.

 

[Chalnoth]

That's really simple.

If you create something from nothing then that nothing becomes something, cause if it were nothing then how did we got something?

As I said it's not logical, and we might as well start believe in witches and fairies if that's what we come to believe.

Begging the question. Try again.

 

[Mordred]

Here is a recent paper involving Guth's model love the new name toy model lol.

http://arxiv.org/abs/1301.5929.

my main point is the model however its changed is still being examined so its still part of our current cosmology. One may wish it would die however in several forms its still being examed and reexamined. However trutfully their is nothing unexpected about that lol

edit having looked closer at this paper I realized that its not related to the subject at hand least as far as I could tell.

 

[Chalnoth]

The original inflation model was taken up and adapted by several different personages.
One of the more recent was Alan Guth

Alan Guth was one of the originators of the Inflation model :)

Generally, Guth and Andreas Albrecht are considered to be the originators of what we know today as inflation, with Guth proposing the original idea, but with significant flaws that made it unworkable, and Albrecht refining that idea into a workable model. Of course, there are many, many other researchers who have put their fingers into the inflation pie, and we know a lot more about inflation now than either did back in the early 80's.

(Edit: I forgot that Albrecht was working with Steinhardt at the time, and according to Wikipedia, Andrei Linde also independently solved the same problem)

The idea that quantum fluctuations could be
responsible for the large scale structure of the universe goes back at least as far
as Sakharov’s 1965 paper [10], and it was re-introduced in the modern context by
Mukhanov and Chibisov [11, 12], who considered the density perturbations arising
during inflation of the Starobinsky [4] type.

Let me point out that this is a different context than the one we've been discussing in this thread. These fluctuations are the ones that started the initial density perturbations which eventually grew to be the galaxy clusters and voids in our universe today. These are not the fluctuations which might have gotten inflation started, but rather the ones that were occurring as inflation was progressing.

 

[big_bounce]

These fluctuations are the ones that started the initial density perturbations which eventually grew to be the galaxy clusters and voids in our universe today. These are not the fluctuations which might have gotten inflation started, but rather the ones that were occurring as inflation was progressing.

That's right . i wanted to say that but I had doubts .
Pure vacuum energy points to before start inflationarry universe but after 1 plank time . If I'm right

 

[Mordred]

Ah thank you for that clarification. I had originally thought Guth was one of the originators but when I did a wiki search it mislead me. I was also having trouble in regards to the others Mukhanov Chibisov etc.
Thanks for also clarifying the distinction.
Its still something I'm currently studying in a self taught manner. Along with a variety of virtual particle models. I have also kept copies that Marcus posted on loop quantm gravity. That I will probably try to figure out next.