Cosmogenesis .

[Cyclone]

I don't have an issue with the idea that our little bit of the universe was possibly more dense in the past.

 

The problem big bang theory is that it doesn't explain the something from nothing, the maths and physics don't work at the point of infinite density, which is would have been if it started with a black hole in a universe that already existed.

How did nothing, non existence suddenly turn into a point of infinite density and what mechanism caused it to expand, what mechanism keeps it expanding.

 

Writing big doesn't change the fact that despite me asking you many many times you still haven't answered these questions.

 

We accept that science hasn't explained or answered all of the questions yet.

 

That doesn't mean you just get to make up any old rubbish and expect it to be taken seriously.

[sutty27]

An eternal universe would be in thermal equilibrium.

 

Only if you believe that matter and energy aren't interchangeable.

 

Its simply not logical to believe that once there was nothing, (something we don't even know is possible) then from nothing existence emerged ( But we don't know how) with a finite life span resulting in it's death only for it to languish for all eternity in it's dead form.

 

How did non existence turn into existence?

 

---------- Post added 13-05-2016 at 07:35 ----------

 

We accept that science hasn't explained or answered all of the questions yet.

 

That doesn't mean you just get to make up any old rubbish and expect it to be taken seriously.

 

That's why I don't take it seriously, all the stuff that is made up to make the Big Bang modal work.

 

And unbeliever does think it is a proven fact hence for several pages I have been trying to convince him that it is not.

 

Which part?

We don't know with absolute precision that the total energy of the universe is zero, but we know that it's close.

We do know the rate of expansion of the universe as a function of time with reasonable precision.

We also know that energy is consistently conserved across the whole spectrum of physical interactions and events.

We don't completely understand inflation (at least last time I checked) but we know it occurred.

As I said earlier, we'll know a lot more in several years down the line when there's a lot more gravitational wave data. The particle physics data from the LHC feeds into this as well in terms of addressing the excess of matter over anti-matter and in general studying the kinds of things which are possible at very high energy densities such as the start of the universe which are reproduced in the LHC collisions.

Hypotheses about the nature of the universe are properly constrained by the data we already have. Although one is free to speculate where such data has yet to be collected.

 

 

Most of the above in unproven assumptions not proven facts.

 

 

And unbeliever asked for our opinions.

 

I'm interested in what the forum thinks on the matter of how the universe started.

I've listed all the options I'm aware of that are reasonably popular.

I've left an "other" just in case...

 

I'd be grateful if those voting other could enlighten me.

 

 

So I am simply doing what he asked members to do in the OP.

 

 

If the event we call Big Bang happened (which is still not confirmed) then it is more likely to have happened in a universe that already existed, it's highly unlikely to have happened out of non existence, something that has never been proven to be possible.

[unbeliever]

Only if you believe that matter and energy aren't interchangeable.

 

All such "interchanges" happen in ways which are consistent with the second law of thermodynamics. Your model (such as it is) is not consistent with the second law of thermodynamics, and various other laws. Therefore it is a load of dingos' kidneys.

As I said before. Not even wrong.

 

Its simply not logical to believe that once there was nothing, (something we don't even know is possible) then from nothing existence emerged ( But we don't know how) with a finite life span resulting in it's death only for it to languish for all eternity in it's dead form.

 

It's the only model which fits the data and is consistent with the laws of physics.

I don't care if it doesn't sit right in your head or whatever else "logical" means to you. The universe doesn't care either.

 

 

An eternal universe would be in thermal equilibrium.

This is an unavoidable consequence of the second law of thermodynamics.

It has been understood for over 150 years.

https://en.wikipedia.org/wiki/Heat_death_paradox

You only have to learn a little bit of 19th century physics to understand this.

Quantum mechanics and general relativity are irrelevant.

[sutty27]

All such "interchanges" happen in ways which are consistent with the second law of thermodynamics. Your model (such as it is) is not consistent with the second law of thermodynamics, and various other laws.

 

Yes it is.

 

It's the only model which fits the data and is consistent with the laws of physics.

It doesn't though, it only fits because of the unproven assumption that have to be made to make it fit.

[unbeliever]

Yes it is.

 

No. It most definitely is not.

You're suggesting that your eternal universe is not in thermodynamic equilibrium because all process which take place in it are reversible. Whilst energy can be converted into matter and vice-versa this only happens in the direction of increasing entropy. That is the essence of the second law of thermodynamics.

Any process which increases entropy brings the universe closer to thermodynamic equilibrium.

 

As I keep trying to tell you:

An eternal universe would be in thermal equilibrium.

This is an unavoidable consequence of the second law of thermodynamics.

It has been understood for over 150 years.

https://en.wikipedia.org/wiki/Heat_death_paradox

You only have to learn a little bit of 19th century physics to understand this.

Quantum mechanics and general relativity are irrelevant.

 

There's no way of escaping this. You can't get around the second law of thermodynamics. Your model is absolute unmitigated nonsense.

[sutty27]

No. It most definitely is not.

You're suggesting that your eternal universe is not in thermodynamic equilibrium because all process which take place in it are reversible. Whilst energy can be converted into matter and vice-versa this only happens in the direction of increasing entropy. That is the essence of the second law of thermodynamics.

Any process which increases entropy brings the universe closer to thermodynamic equilibrium.

 

 

If our universe had a start and is a one time only event, and is indeed expanding and will expand for ever then it will reach thermodynamic equilibrium in the very distant future.

 

But this wouldn't happen in an infinite universe with no begging because the big bank assuming it happened wouldn't be a one time only event.

 

 

You claim the universe emerged from non existence which must have already been in a state of thermodynamic equilibrium, otherwise it wouldn't have been nothing, it would have been something.

So how did nothing with no physical, mechanical, chemical, or thermal processes spontaneously change into a universe that does have physical, mechanical, chemical, or thermal processes?

Edited May 13, 2016 by sutty27

[unbeliever]

If our universe had a start and is a one time only event, and is indeed expanding and will expand for ever then it will reach thermodynamic equilibrium in the very distant future.

 

But this wouldn't happen in an infinite universe with no begging because the big bank assuming it happened wouldn't be a one time only event.

 

 

You claim the universe emerged from non existence which must have already been in a state of thermodynamic equilibrium, otherwise it wouldn't have been nothing, it would have been something.

So how did nothing with no physical, mechanical, chemical, or thermal processes spontaneously change into a universe that does have physical, mechanical, chemical, or thermal processes?

 

Making the universe spatially infinite does not prevent it reaching thermodynamic equilibrium.

There's nothing in the laws of physics to prevent spontaneous cosmogenesis. Nor is there any reason to assert that the void from which the universe emerged needs to be in thermodynamic equilibrium as there need be no processes in the void which drive it toward thermodynamic equilibrium. Nor is there any indication that an environment in thermodynamic equilibrium is incapable of producing a vacuum fluctuation leading to the formation of a universe.

There are however a myriad of processes in this universe which drive it inexorably toward thermodynamic equilibrium.

The fact that you find all this difficult to wrap your head around is neither here nor there.

 

 

An eternal universe (infinite or not) would be in thermal equilibrium.

This is an unavoidable consequence of the second law of thermodynamics.

It has been understood for over 150 years.

https://en.wikipedia.org/wiki/Heat_death_paradox

You only have to learn a little bit of 19th century physics to understand this.

Quantum mechanics and general relativity are irrelevant.

 

There's no way of escaping this. You can't get around the second law of thermodynamics. Your model is absolute unmitigated nonsense.

Edited May 13, 2016 by unbeliever

[sutty27]

Making the universe spatially infinite does not prevent it reaching thermodynamic equilibrium.

There's nothing in the laws of physics to prevent spontaneous cosmogenesis.

 

The laws of physics only apply to the universe they don't apply to non existence.

 

If laws of physics don't prevent spontaneous cosmogenesis then it can happen infinite times in an infinate universe meaning that the universe can't reach thermodynamic equilibrium.

 

 

 

 

 

Nor is there any reason to assert that the void from which the universe emerged needs to be in thermodynamic equilibrium as there need be no processes in the void which drive it toward thermodynamic equilibrium.

Nor is there any indication that an environment in thermodynamic equilibrium is incapable of producing a vacuum fluctuation leading to the formation of a universe.

 

The vacuum is part of the universe, if the universe had a start point then the vacuum didn't exist before it started so no vacuum fluctuations, you casn't apply the laws of physics to try and explain how everything came from nothing.

 

Physics is the branch of science concerned with the nature and properties of matter and energy.

 

If matter and energy existed prior to what you say was the start of the universe then the universe clearly already existed and what we see today is just an event in the universe which already existed.

 

There are however a myriad of processes in this universe which drive it inexorably toward thermodynamic equilibrium.

Only if you assume that it's finite with a beginning.

[unbeliever]

The laws of physics only apply to the universe they don't apply to non existence.

 

Some of them, yes.

 

If laws of physics don't prevent spontaneous cosmogenesis then it can happen infinite times in an infinate universe meaning that the universe can't reach thermodynamic equilibrium.

 

 

New universes born out of vacuum fluctuations in existing universes would be discrete and not part of the parent universe. If our universe was born in such a way rather than out of the void, then it makes no practical difference to anything we're discussing.

 

The vacuum is part of the universe, if the universe had a start point then the vacuum didn't exist before it started so no vacuum fluctuations, you can't apply the laws of physics to try and explain how everything came from nothing.

 

Didn't say vacuum, said void. Not the same thing.

 

Physics is the branch of science concerned with the nature and properties of matter and energy.

It's not limited to that.

 

If matter and energy existed prior to what you say was the start of the universe then the universe clearly already existed and what we see today is just an event in the universe which already existed.

 

There is no need for matter and energy to have existed prior to the start of the universe in the big bang model. Vacuum fluctuations are zero-sum.

 

Only if you assume that it's finite with a beginning.

 

On the contrary. The second law of thermodynamics includes no such assumption.

 

An eternal universe (infinite or not) would be in thermal equilibrium.

This is an unavoidable consequence of the second law of thermodynamics.

It has been understood for over 150 years.

https://en.wikipedia.org/wiki/Heat_death_paradox

You only have to learn a little bit of 19th century physics to understand this.

Quantum mechanics and general relativity are irrelevant.

 

There's no way of escaping this. You can't get around the second law of thermodynamics. Your model is absolute unmitigated nonsense.

[sutty27]

Some of them, yes.

 

 

 

New universes born out of vacuum fluctuations in existing universes would be discrete and not part of the parent universe. If our universe was born in such a way rather than out of the void, then it makes no practical difference to anything we're discussing.

It wouldn't be a new universe it would be part of the already existing universe.

 

 

 

 

Didn't say vacuum, said void. Not the same thing.

 

You said vacuum fluctuation, hence vacuum, a void is an empty space, and if the big bang created everything, prior to it's creation there wasn't any empty space.

 

 

 

It's not limited to that.

Well it definitely doesn't apply to non existence.

 

 

 

There is no need for matter and energy to have existed prior to the start of the universe in the big bang model. Vacuum fluctuations are zero-sum.

There's an need for a vacuum and that didn't exist, and vacuum energy is energy.