Big Bang not an instance of something from nothing?

[Area54]

3 hours ago, Airbrush said:

Then try your best to explain how a finite size can grow to an infinite size.   I am eager to learn.

As for what exactly is "nothing", is it simply the absence of all matter or energy?

If you read back through the thread you will find me enquiring as to whether or not it might be possible. I had no idea how it might come about, but I do not presume that my ignorance means it is impossible. My ignorance is really quite extensive and if I based my belief of what is possible on what I found credible, or what I knew was possible then I would be even more messed up than I am.

And I notice you never actually answered my question. So, I'll turn it into a statement. I believe you were using an argument from personal incredulity.

[StringJunky]

4 hours ago, Airbrush said:

Then try your best to explain how a finite size can grow to an infinite size.   I am eager to learn.

As for what exactly is "nothing", is it simply the absence of all matter or energy?

 

'Nothing' could be a placeholder word for 'We don't know'

[Airbrush]

23 hours ago, Area54 said:

If you read back through the thread you will find me enquiring as to whether or not it might be possible. I had no idea how it might come about, but I do not presume that my ignorance means it is impossible. My ignorance is really quite extensive and if I based my belief of what is possible on what I found credible, or what I knew was possible then I would be even more messed up than I am.

And I notice you never actually answered my question. So, I'll turn it into a statement. I believe you were using an argument from personal incredulity.

Yes personal incredulity to be exact.  In all the cosmology documentaries I've seen on Science Channel, never once did anyone mention a finite size growing to an infinite size in a finite amount of time.  Even if the universe grew a Trillion times every second, since the big bang, if it was finite at the start it would still be finite.  Infinity is a different animal.

Can anyone explain how the "tan function" is a model for a finite universe growing to an infinite size in a finite amount of time?  I forgot all my trig from high school.

 

[redhawk1974]

If everything was gathered together and exploded out in a big bang then would it not be possible that at some point in time everything going outward eventually stops expanding outwards and then gets sucked back in and gathers back into one place yet again and then cycle could repeat ? 

[beecee]

18 minutes ago, redhawk1974 said:

If everything was gathered together and exploded out in a big bang then would it not be possible that at some point in time everything going outward eventually stops expanding outwards and then gets sucked back in and gathers back into one place yet again and then cycle could repeat ? 

Firstly the BB was not an explosion: It was the evolution and expansion of space and time  (in the first instance, matter came later) from a hot dense state. Secondly, we have absolutely no evidence that any recollapse will occur, in fact recent observations of the expansion accelerating, is evidence against any recollapse.

[Area54]

19 hours ago, redhawk1974 said:

If everything was gathered together and exploded out in a big bang then would it not be possible that at some point in time everything going outward eventually stops expanding outwards and then gets sucked back in and gathers back into one place yet again and then cycle could repeat ? 

beecee's post is accurate, but until recently the possibity of future collapse, or of repeated recycling, was considered quite feasible, just as you suggest.

[MigL]

So Airbrush, you can accept a universe infinite in 'size', but not one infinite in 'rate of growth'.
Infinite is infinite; either you accept 'infinite' as a possibility or you don't. But don't pick and choose.

And another point I've previously made, as you wind the clock back towards T=0, you eventually get to the point where geometry is undefined ( in the space and time dimensions ). and since conservation laws of mass/energy and momentum arise because the Lagrangian is symmetric under translations in time and space ( see Noether's Theorem ), neither can be assumed to retain validity as you approach T=0.
IE, maybe you can have infinite mass/energy arise from nothing.

[Mordred]

And maybe energy is simply the ability to perform work and is an emergent system property. Not something that needs to be created or destroyed as it is a property and not a thing unto itself.

Coincidentally mass is the same way. Keep in mind you still have the conservation laws, 

(the above provides the key to understanding the universe from nothing model)

Edited September 11, 2017 by Mordred

[MigL]

Sure, but it makes perfect sense to speak of energy as a property of the universe in the very early times.
Just as it makes sense to speak of the temperature of the universe ( related to its energy ), before there were any particles to give the statistical interpretation of temperature.

Since you cannot have symmetry in temporal or spatial translation as time approaches T=0 ( at which point, there is only one direction ), I don't see how conservation laws can still be valid.

 

[Mordred]

I agree however the FLRW metric treats the Conservation laws as valud under the ideal fluid, adiabatic and isentropic expansion system.

The universe from Nothing model also treats the universe at any moment under the same definitions. 

This is a common misconception to the Universe from Nothing model, that it violates the Conservation laws, however within its mathematics it is constructed to preserve those laws.

The thing is we cannot measure "An absolute/true energy state." Hopefully this descriptive doesn't cause sphincters to compress, but lanquage has its limits.

We can only measure energy, relative to another arbitrary field coordinate. So we can only measure the potential differences in a field as your energy values. aka the definition of potential energy. (Energy due to an objects position within some field )

You often see this described roughly in numerous QFT literature.

The "absolute true" energy value is beyond any viable means to determine and can literally be any arbitrary value. We can never know orherwise.

Under math [latex] F_e=0[/latex]  (field energy) is literally the potential energy difference to the observer from the emitter. Change the coordinates of either and your energy value also changes. However to any observers in the reference frame of emitter. No change occurs in the emitter. ( just like voltage we require a potential difference to measure)

So one must be careful how one defines a conservation law under observations via relativity. Which quite frankly cannot decide if the conservation laws are applicable under relativity.

Think of it this way, all possible "Observers" are Within the system. Measuring a true energy field value requires an Observer outside the system, not one within.

The above also applies to "fundamental vs absolute observers. A fundamental observer in LCDM is not an absolute observer. We have no viable absolute observers.

No an Ether based absolute frame doesn't count, its still part of the system. (assuming there is an ether, which we know there is no evidence supporting such). It was a hopeful idea of finding a an "invariant reference frame, within our system".

Under GR all reference frames are inertial (variant). Lol if you include the above with the understanding that particles are field excitations. Then particles arise due to potential differences. ( quite frankly that is an obvious statement) once you accept the field excitation definition of a particle. The "rest mass" being an invariant quantity. Invariant to all observers quantity. The relativistic mass being the variant quantity.

A good way to explore the above is look at what happens to the number of particles within a box to different observers, where you get a different quantity of photons ( quanta) to different observers.

Important caveat. One often sees the statement "The universe at any given time has roughly 10^90 particles"

That is only true to fundamental observers...

(The Nothing in the model literally means to an observer in the same field potential. The universe arises from anistophy regions and how they evolve in our field potentials. (Potential energy).

Far too often the observer limitations of any given model is a missed detail in understanding those models. Lets take an example.

QED, look specifically at the IR/UV cutoffs, those cutoffs are specifically chosen, as they are defined by the killing vectors to a specified type of observer.

Every field treatnent theory is defined by the limits of the observer killing vectors of that system state.

 

 

Edited September 12, 2017 by Mordred

[Mordred]

8 hours ago, MigL said:

So Airbrush, you can accept a universe infinite in 'size', but not one infinite in 'rate of growth'.
Infinite is infinite; either you accept 'infinite' as a possibility or you don't. But don't pick and choose.

And another point I've previously made, as you wind the clock back towards T=0, you eventually get to the point where geometry is undefined ( in the space and time dimensions ). and since conservation laws of mass/energy and momentum arise because the Lagrangian is symmetric under translations in time and space ( see Noether's Theorem ), neither can be assumed to retain validity as you approach T=0.
IE, maybe you can have infinite mass/energy arise from nothing.

the above involving those killing vectors. ( For other readers, invluding OP. Migl already knows the above) she is ( if I recall correctly) too consistent with her posts in related threads, not to understand anything I posted above.

Edited September 12, 2017 by Mordred

[Strange]

5 hours ago, Mordred said:

the above involving those killing vectors.

Without the capital K it makes mathematics sound more dangerous than it is!

[MigL]

Thanks for the clarifications Mordred.

It is very hard not to put yourself ( as the observer ), 'outside' the universe as it shrinks back towards T=0.
Should have realized that gauge quantities ( where we measure differences as opposed to absolutes ) are a problem just like total energy conservation in GR. You cannot say anything about it because measuring energy in and out of the system involves being 'outside' the system.

[Airbrush]

On ‎9‎/‎11‎/‎2017 at 10:05 AM, MigL said:

So Airbrush, you can accept a universe infinite in 'size', but not one infinite in 'rate of growth'.
Infinite is infinite; either you accept 'infinite' as a possibility or you don't. But don't pick and choose.

Interesting point that I never considered, thanks for that!  Yet that increases my doubt about a SINGLE infinite structure called "universe".  Thanks again.  All we have seen so far are higher levels of finite organization (galaxies, clusters, and superclusters). 

Edited September 12, 2017 by Airbrush

[beecee]

On 7/29/2017 at 5:32 AM, Airbrush said:

"... the universe is the ultimate free lunch!  It came from nothing, and its total energy is zero, but it nevertheless has incredible structure and complexity. There could even be many other such universes, spatially distinct from ours."

Excellent article and not too difficult for me.

What about the incredible structure and complexity of the universe?  That is not nothing.  The universe did not come from nothing, it came from zero energy, some kind of potential condition from which a universe can appear.

The complexity and structure arose from whatever we chose to define as nothing...the quantum foam...virtual particles etc.

I came across a "TED" talk yesterday given in a similar non complicated narrative: It is a bit long around 18 minutes but I believe you should enjoy and possibly benefit from: I know I did. 

https://www.ted.com/talks/david_christian_big_history/transcript?language=en

 

[Dubbelosix]

On 26/07/2017 at 8:18 PM, Alfred001 said:

I found the above quote on Quora, but I'm not registered there and I don't know how the damn thing works and it was an old post, so I'll ask here, what does the guy mean by the Big Bang not being something from nothing?

 

 

I love this old chestnut, because it seems to be the one question almost all novice and actual academics struggle with. The big bang may not be the (beginning to everything) in which the early models considered as resulting from a singularity. Does the universe, or any post existence of a universe, imply it can come from nothing?

 

Well ... arguably, with the [right model] yes you can, in some ad hoc way show that a universe can arise from nothing, using only the dynamics of gravity. I have a really nice quote of Hawking in an unpublished work of mine on my computer I will search iit out for you. 

Found it: 

 

''Because there is such a law as gravity, the universe can and will, create itself from nothing.''

 

Hawking

I say ad hoc for a good reason, because in my own experience, it makes no philosophical sense to say something comes from nothing, and while philosophy is not generally trained into the scientist, logic should.

... For how can something come from nothing? 

 

It doesn't even make sense.

Unless you define nothing as

 

1) nothing 

2) absolute nothing

 

But then, how does nothing and absolute nothing differ, unless nothing wasn't actually nothing?

On 11/09/2017 at 7:09 PM, Mordred said:

And maybe energy is simply the ability to perform work and is an emergent system property. Not something that needs to be created or destroyed as it is a property and not a thing unto itself.

Coincidentally mass is the same way. Keep in mind you still have the conservation laws, 

(the above provides the key to understanding the universe from nothing model)

Though you know what side I am on

 

I think of the big bang related to chaotic and non-conserved processes -  I don't think I ever explained this to you, but when I think about big bang models incorporating singularities as involving the squeezing of the matter and energy into a condensed point, is unphysical for obvious reasons - it is akin to the problems of making a point in general relativity from a sphere, you will find its curvature inflate to infinity!

 

The situation of the big bang though, is perfect for non-conserving dynamics. Curvature is the only interesting thing when a universe is young, and Wilczek has shown that it is possible that gravity has a ... complimentary existence, if you will, with the electromagnetic force. He shows it is entirely consistent that as gravity increases as you reduce the size of a universe, it's charge tends to zero. This makes sense for particles in the early cosmology without charge and before electroweak symmetry breaking.

Edited September 28, 2017 by Dubbelosix

[Mordred]

ok measure an electric field with no potential difference between DMM leads.

Now apply that to a field, with absolutely zero difference in field values. 

Now add a potential difference in field values lo and behold suddenly an energy value arises and that field is more capable of performing work.

Energy is the ability to perform work.

 

Define potential energy under physics.

"the energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors"

One factor is anistropy in field values.

 

Now with those definitions firmly implanted read 

"On the zero energy universe"

https://arxiv.org/abs/gr-qc/0605063

 

see the conservation of energy/momentum juggling act with the potential and kinetic terms?

 I realize this paper is in GR formalism.

 

Edited September 28, 2017 by Mordred

[Airbrush]

14 hours ago, Dubbelosix said:

... For how can something come from nothing? 

It doesn't even make sense.

Unless you define nothing as

1) nothing 

2) absolute nothing

But then, how does nothing and absolute nothing differ, unless nothing wasn't actually nothing?

Though you know what side I am on

Something can come from nothing because "nothing" is not understood.  It's not what it seems.

"Absolute nothing" is only an idea and nothing can be known about it.

Yes, "nothing wasn't actually nothing"! 

[Dubbelosix]

Then its not really nothing. Not as we understand it.

[Mordred]

49 minutes ago, Dubbelosix said:

Then its not really nothing. Not as we understand it.

correct, but then most people don't understand energy either lol

[Dubbelosix]

I saw a popular writer once state, ''instead of thinking about nothingness before the big bang, maybe we should start thinking about everythingness.''

[Mordred]

Its a good policy to understand what we can measure first. On a side note, I always find it somewhat amusing that we are all taught in high school the above definition. Yet when we start thinking cosmology, GR and QFT. Everyone forgets them

[Dubbelosix]

Yeah its interesting.

 

It's also interesting how, (I think) it also shows, that philosophy is crucial in science - and sometimes, logic and philosophy are indistinguishable. 

Edited September 29, 2017 by Dubbelosix

[beecee]

2 hours ago, Dubbelosix said:

Then its not really nothing. Not as we understand it.

So our definition of "nothing" needs reappraisal? I absolutely agree. Is the quantum foam from which the BB arose nothing? Are virtual particles nothing?   Besides liking Lawrence Krauss and his universe from nothing thoughts, I have posted a few times before the following........https://www.astrosociety.org/publication/a-universe-from-nothing/

1 hour ago, Dubbelosix said:

Yeah its interesting.

It's also interesting how, (I think) it also shows, that philosophy is crucial in science - and sometimes, logic and philosophy are indistinguishable. 

As one who also adheres to the Krauss view on philosophy and as one who has been in a recent debate with a couple of other "philosophy supporters" who were in disagreement with his views, [and mine] I did actually mention re the scientific methodology being a common sense logical structure, which we all in some way [even lay people such as myself] follow everyday. http://www.scienceforums.net/topic/109509-philosophy-split-from-sam-harris-thread/?page=3&tab=comments#comment-1015087

 

[Dubbelosix]

25 minutes ago, beecee said:

So our definition of "nothing" needs reappraisal?

Maybe. My picture really is no more clear cut than other peoples. I think this struggle about the universe from nothing, is a common one.