Why Stephen Hawking says universe can create itself from nothing?

big_bounce
Messages
102
Reaction score
3
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 .
 
Last edited:
Space news on Phys.org
big_bounce said:
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?
:rolleyes:
Energy is a mere concept. A useful idea if the only brain you have is a poor human one :rolleyes:

We cannot say "came from" because if so that would be "before the beginning"
 
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?
 
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.
 
Last edited:
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
 
MathematicalPhysicist said:
You should really not listen to this nonsense.

I don't care how intelligent Stephen is, nothing can be created from nothing,
Why not?
 
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.
 
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.
 
MathematicalPhysicist said:
Cause to create something from nothing you need to do something illogical, magical, mystical.
Prove it.
 
  • #10
MathematicalPhysicist said:
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.

.
 
  • #11
Lawrence Krause has a whole book about this, "A Universe from Nothing", in which he supports this theory.
 
  • #12
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
 
  • #13
Johninch said:
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)".
 
  • #14
MathematicalPhysicist said:
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.

Chalnoth said:
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?
 
  • #15
rbj said:
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.
 
  • #16
phinds said:
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.
 
  • #17
Chalnoth said:
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".
 
  • #18
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...
 
  • #19
rbj said:
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.
 
  • #20
Chalnoth said:
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.
 
  • #21
Chalnoth said:
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


MathematicalPhysicist said:
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 ?
 
Last edited:
  • #22
I meant ,
Since there was nothing except energy and we know elementary particles are not energy , so universe and elementary particles came from nothing .
 
Last edited:
  • #23
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.
 
  • #24
big_bounce said:
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" :biggrin:

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?
 
  • #25
rbj said:
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)
 
Last edited:
  • #26
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.
 
Last edited:
  • #27
marcus said:
... 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 :smile:
 
  • #28
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
 
  • #29
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
 
Last edited:
  • #30
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.
 
  • #31
MathematicalPhysicist said:
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.
 
  • #32
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.
 
Last edited:
  • #33
Mordred said:
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)

Mordred said:
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.
 
  • #34
Chalnoth said:
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
 
  • #35
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.
 
  • #36
=sigh=
i noticed you avoided the question i asked.

oh well. it's tiresome to repeat, and my experience with you is that (repetition) is what has to happen to keep you on topic. or at least, on the narrow topic of the question asked.

Chalnoth said:
But when you say something is impossible, that requires a mathematical proof.

i wouldn't confuse the disciplines of "logic" and "mathematics". they're closely related disciplines but not the same. i would say that logic is a more primary discipline (i.e. mathematics necessarily employs logic but not the other way around). logic doesn't require quantitative foundation except for the boolean. i hope we don't get into a dispute of semantics.

and I've seen very goofy claims of "mathematical proofs" both from theists (like Stephen Unwin) who claim to "mathematically prove" God exists and atheists (like Richard Dawkins) who "mathematically prove" the opposite. both are goofy, so be careful with that semantic, Noth. you could be heading for a very unimpressive crash.

the question regarding what is possible is directed toward physical reality. so we're not talking about what is possible for Middle Earth and wizards like Gandalf the White vs. Gandalf the Gray. so, even though mathematics is necessary to describe physics (logic isn't enough, there are quantitative relationships involved), mathematics isn't sufficient. there are also the physical axioms.

i have a glimpse of the concept of a quantum fluctuation. i have a crude electrical engineer's concept of QM and understand what the quantity \Psi is about. and regarding that, i understand that a particle like a subatomic particle can pop into existence at some place and time. or at least appear to when we measure things. the probabilities of such are reasonable for particles so small. but it seems like a fantastic stretch to apply that to entire universes. especially coming from people who reject the supernatural, it's as if they're just choosing a different supernatural, one more to their liking. I'm thinking of Dawkins, so please don't take this as directed toward you, Noth.

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?

empty set. i know, it's still a set. but that's why i am not on board with your semantic to begin with.

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.

real "nothing" would be no physical quantity (what i like to call "stuff") and no relationships or law of interaction either. and no one around to behold it.
 
  • #37
I notice you go to great lengths to avoid addressing real science issues by imposing logical constraints amenable with your world view, rbj.
 
  • #38
MathematicalPhysicist said:
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.

I don’t agree. I explained it and you ignored my argument. What’s wrong with it?

To repeat:
Creation is going on all the time in so called empty space, with matter and antimatter particles annihilating each other, as a natural process.
If a similar process occurred at the start of the BB without a perfect annihilation, we would be left with separate amounts of matter and antimatter, adding to zero.

By the division of an original nothing into two positive and negative parts, there is a creation, but it doesn’t have to offend any laws of physics or logic, does it?

I agree that two separate and opposite quantities equating to zero are not nothing, but my explanation answers your question of how we got something from nothing, does it not?

Chronos said:
I notice you go to great lengths to avoid addressing real science issues by imposing logical constraints amenable with your world view, rbj.

I don’t know if the logical constraints which you say rbj seeks to impose are biased by his world view.

However, I do think that it is very necessary that we impose rational and logical constraints when we are addressing science issues, otherwise we get these accusations of witches and fairies.
Scientific theories and hypotheses have to stand the test of logic as well as mathematics.

.
 
  • #39
Johninch said:
Scientific theories and hypotheses have to stand the test of logic as well as mathematics.

Not at all. Scientific theories must only stand the test of experiment. If it turns out that experiment is incompatible with logic and mathematics, then logic and mathematics will have to change.
 
  • #40
micromass said:
Not at all. Scientific theories must only stand the test of experiment. If it turns out that experiment is incompatible with logic and mathematics, then logic and mathematics will have to change.

It's difficult to make experiments in cosmology, particularly concerning the BB, so we have to fall back on observations and mathematics. Ideally all the information should match. But I don't see how we can exclude logic - you mean we don't have to think straight?

The main problem with your argument is that you seem to be ignoring the necessity to interpret the results of experiments, as if they all lead to obvious conclusions. Quite apart from quality problems in the execution in some cases.

.
 
  • #41
Johninch said:
It's difficult to make experiments in cosmology, particularly concerning the BB, so we have to fall back on observations and mathematics. Ideally all the information should match. But I don't see how we can exclude logic - you mean we don't have to think straight?

You seem to be equation logic with thinking straight. Logic is a mathematical discipline with a very specific meaning.Furthermore, the current accepted logical system in mathematics is classical logic. This has already been shown not to model reality. So we already had to abandon (classical) logic and find a new kind of logic.

The main problem with your argument is that you seem to be ignoring the necessity to interpret the results of experiments, as if they all lead to obvious conclusions. Quite apart from quality problems in the execution in some cases.

I don't see how I ignored anything. In science, you make experiments and observations to test your theories. If eventually they seem to contradict the established theory (and if there are no errors), then the theory is wrong. This includes logic and mathematics. I see no a priori reasons why mathematics should be able to model this world. In fact, I speculate that it probably doesn't (but this is just a guess, I have no single shred of proof or evidence for it).
 
  • #42
marcus said:
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.)

As stated I went and looked into the history of developments on the various inflationary/expansion models. After some extensive searching I realize what your saying in your previous post.

Here is what I've found out.

false vacuum became old inflation later replaced by new inflation. Due to problems in new inflation it later became chaotic eternal inflation. There are other models that derived from the original false vaccuum. However all these models failed to solve one key problem that of pocket/multi universe formation.
As far as I can tell string theory is currently working with Guth I can't recall what string theory model is representative in this line of research DQ something lol. I don't follow string theory it makes my teeth ache.

This paper is the latest I could find that involved false vacuum
http://arxiv.org/abs/1112.3005

At first I thought of starting a new thread on it however I quickly realized that there are aspects in it that I don't quite agree with. However that's another topic.
 
  • #43
Chronos said:
I notice you go to great lengths to avoid addressing real science issues by imposing logical constraints amenable with your world view, rbj.

Johninch said:
I don’t know if the logical constraints which you say rbj seeks to impose are biased by his world view.

besides that, i would like to know what real science issues i am going to great lengths to avoid. what are they? certainly not that "science" is about what is material and empirical. that real science issue is something that i push relentlessly.

perhaps it's that i don't afford "science" the totality of reality in my worldview. (i.e. i do not subscribe to the belief system of "Materialism" or "Physicalism". and, BTW, neither do John Polkinghorne, Freeman Dyson, or Owen Gingerich as best as i understand what they say and write.) is that it, Chronos?

However, I do think that it is very necessary that we impose rational and logical constraints when we are addressing science issues, otherwise we get these accusations of witches and fairies.
Scientific theories and hypotheses have to stand the test of logic as well as mathematics.

it looks like PF Mentor micromass has weighed in on this issue on the other side. and, from previous experience, i have to be careful not to say something that whoever admin doesn't like (Greg seems to be fine, but it's the captains under him).

anyway, having done work in science (only in acoustics - totally classical physics), engineering mathematics, and in logic, i must dispute a few things said here:

logic is not a sub-discipline of mathematics but it is the other way around.

i would disagree with this:

micromass said:
Scientific theories must only stand the test of experiment. If it turns out that experiment is incompatible with logic and mathematics, then logic and mathematics will have to change.

even when the experimenter is hallucinating? when the astronomer is peaking into his telescope and sees teapots or spaghetti monsters or even the same guy with a beard in Michelangelo's Sistine Chapel painting, he might need to question the empirical outcome of the experiment.

micromass said:
You seem to be equati[ng] logic with thinking straight.

he's not the only one. so did Aristotle (and quite a few others of his descent). might want to look up "logic" and "term logic" in wikipedia. (again, not to say that wikipedia is accurate in all things, but this looks reasonably decent.)

these formal rules of logic are solely about thinking straight. it's about applying consistency and about being clear about what a premise says and what it does not say.

Logic is a mathematical discipline with a very specific meaning.

perhaps logic in mathematics is a mathematical discipline, but otherwise that statement is false in that it is not sufficiently broad.

mathematics is about quantity (among other things like structure, but mainly about quantity). except in the boolean sense, logic need not be. and although quantity can be assigned boolean variables, it need not be. "value" is not exactly the same thing as "quantity".

logic, as a discipline, contains mathematics (when quantity is introduced to the discussion), and science (when the empirical and material are introduced to the discussion), and sociology, politics, and law (when human beings and human behavior are brought into the discussion), and, if i dare say so, religion (when notions of God and the metaphysical are brought into the discussion). and even this statement from me is also not sufficiently broad.
 
  • #44
rbj said:
real "nothing" would be no physical quantity (what i like to call "stuff") and no relationships or law of interaction either. and no one around to behold it.

The link below is including so many physical quantities that exist in universe .
Can you prove these quantities came from energy ? or came from another quantity ?
If you can not , that mean they came from real "nothing" .

http://en.wikipedia.org/wiki/List_of_physical_quantities
 
  • #45
This is what happens when you abandon a mathematical discussion and start arguing metaphysics and philosophy which are disciplines that go nowhere and terminate in pointless non mathematical / non empirical arguments and frankly Chalnoth hit the nail on the head many posts ago when he said "We don't know" as of now.
 
  • #46
big_bounce said:
The link below is including so many physical quantities that exist in universe .
Can you prove these quantities came from energy ?
This statement makes no sense whatsoever. Energy is a physical property of matter (pedantically, it is a property of every quantum-mechanical field).

big_bounce said:
or came from another quantity ?
If you can not , that mean they came from real "nothing" .
This is also incorrect. Just because we don't know how these physical quantities arose, that doesn't mean that you get to automatically substitute your favored explanation in its absence.
 
  • #47
WannabeNewton said:
This is what happens when you abandon a mathematical discussion and start arguing metaphysics and philosophy which are disciplines that go nowhere and terminate in pointless non mathematical / non empirical arguments and frankly Chalnoth hit the nail on the head many posts ago when he said "We don't know" as of now.

Well said I for one, like many others have gotten tired of the pointless bickering going on.
Debating is one thing, provided supporting articles, mathematics or reasonable analysis is included is one thing.
Personal based arguments is quite another.
If you have a problem with a model, then take the time to provide supporting evidence or problems with THAT given model.
If you look at this thread carefully enough some of the problems of false energy has been stated. The one that stands out the most is the problem of stopping the inflation.
That lead to a multiple of alternate modifications. Some of which I listed.
If I as NON scientist can spend the time looking for problems in a given model AND supply supporting material. Then so can anyone else.
 
  • #48
Chalnoth posted:

...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...

Are these necessarily different perturbations...??

In a very new series of papers from Ashtekar, et al, [recently discussed here] it seemed the authors had found consistent inflationary perturbations all the way back in the Planck regime...


Using LQG ideas and techniques, we have extended the inflationary paradigm all the way to the deep Planck regime. At the big bounce, one can specify natural initial conditions for the quantum state Ψo that encodes the background homogeneous quantum geometry, as well as for ψ that describes the quantum state of perturbations. There is a precise sense in which generic initial conditions for the background lead to a slow roll phase compatible with the 7 year WMAP data...

[I think Marcus had started a thread referencing these papers, but I did not record the thread link..]


A Quantum Gravity Extension of the Inflationary Scenario
Ivan Agullo, Abhay Ashtekar, William Nelson
(Submitted on 7 Sep 2012)
http://arxiv.org/abs/1209.1609


The pre-inflationary dynamics of loop quantum cosmology:

Confronting quantum gravity with observations
Ivan Agullo, Abhay Ashtekar, and William Nelson

...Using techniques from loop quantum gravity, the standard theory of cosmological perturbations was recently generalized to encompass the Planck era. We now apply this framework to explore pre-inflationary dynamics. The framework enables us to isolate and resolve the true trans-Planckian difficulties, with interesting lessons both for theory and observations. Specifically, for a large class of initial conditions at the bounce, we are led to a self consistent extension of the inflationary paradigm over the 11 orders of magnitude in density and curvature, from the big bounce to the onset of slow roll.
 
  • #49
Certainly. Anything with "Nothing/create" are good catch phrases. Zero/uncertainty to entropy to universe. Might want to check "The information as absolute" by S.V. Shevchenko, V.V. Tokarevsky.

http://arxiv.org/abs/1004.3712.

In informational conception the unique fundamental essence that exists is absolutely infinite Set “Information”, which include, for example, subset “Matter”; all what one sees is/are “words”.
Any element of the Set contains the Set totally because of to define the element is necessary to point out all differences of given element from every other element in the Set. The element “nothing” is only one of the Set’s elements –i.e. dynamical null set.

'Nothing' is fairly complicated stuff. You have to define nothing in specific way. The idea of "nothing" stems from this notion of a collection and analogous to empty set. So we can think of "nothing" as a term describing the set itself and not a necessity of zero in mathematical language. The universe might came from uncertainty. Nothing can only make sense if given limitations but can be use in both accounts.

Nothing is our imaginative construct to make sense of specific order in a specific task. It is associated with the mathematicians new concept of "zero" (as a number without any magnitude). It is a formal "nothing", like zero, but made up of +1 and -1, or equal amounts of positive and negative charges, or even completely balanced forces which give the appearance of zero activity, and, of course, many others of similar ilk.

To say that the universe came from nothing is a "fair assumption" relative to what we 'currently' know to a certain (v) degree of confidence.
 
  • #50
WannabeNewton said:
... and frankly Chalnoth hit the nail on the head many posts ago when he said "We don't know" as of now.

it hadn't been the instances when Chalnoth says "We don't know" that i had ever disputed what he/she said.

it was, in fact, the instances when he should have said "We don't know", and said something quite different (and virtually diametrically opposite) that i took issue with what he said. at least in the other multiverse thread.
 
Back
Top