Part of the Big Bang perplexes me

[Silvestru]

31 minutes ago, MarkE said:

All energy together make up the value 1, and all gravity makes up the value of -1, which makes 0, and therefore a flat universe. Observations support the zero-energy universe idea, that matter (positive) is cancelled out by gravitational attraction (negative). There is a constant in the Friedmann–Lemaître–Robertson–Walker metric that determines whether the universe is curved and infinite, curved and finite, or flat. The energy densities for those three curvature cases are positive, negative, and zero.

I think you are talking about the density parameter (not a constant) but you are wrong.

• Quote

   

  • If Ω = 1, the universe is flat
  • If Ω > 1, there is positive curvature
  • if Ω < 1 there is negative curvature

   

   

8 minutes ago, wallflash said:

Is this everything not energy?

Ok but energy is a property. It is not expanding.

The quote from MarkE was:

Quote

 The fact that there is energy in the first place, and that it is expanding

It's like me saying that the viscosity is expanding, what about location or boiling point? Those are also properties. Are those also expanding?

[StringJunky]

25 minutes ago, wallflash said:

 

 

True, but this "everywhere" would be in one infinitesimally small and dense  point if it began from one singularity.

 

Yes. Whatever the size of the universe it is 'everywhere'. The error some people make  in visualising the universe is from the position of being outside of it when you can only ever be inside.

[wallflash]

23 minutes ago, Silvestru said:

 

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Ok but energy is a property. It is not expanding.

 

 If the universe is comprised of energy, and the universe is expanding , is the energy that makes up the universe expanding or more energy-space being created ? How would the universe expand without one of these concepts being necessary?

[Silvestru]

9 minutes ago, wallflash said:

 If the universe is comprised of energy, and the universe is expanding , is the energy that makes up the universe expanding or more energy-space being created ? How would the universe expand without one of these concepts being necessary?

Well...ignoring the fact that you didn't read my previous comment about how it's a property....  it's called the Law of Conservation of Energy.

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

Lets take your example about the expansion of the universe: New "volume" is created as space expands but it also releases stored gravitational potential energy which converts into intrinsic energy that fills that volume. It all evens out.

This is also a part of https://en.wikipedia.org/wiki/General_relativity

 

Edited March 27, 2018 by Silvestru

[wallflash]

36 minutes ago, Silvestru said:

Well...ignoring the fact that you didn't read my previous comment about how it's a property....  it's called the Law of Conservation of Energy.

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

Lets take your example about the expansion of the universe: New "volume" is created as space expands but it also releases stored gravitational potential energy which converts into inartistic energy that fills that volume. It all evens out.

This is also a part of https://en.wikipedia.org/wiki/General_relativity

 

I didn't ignore it, simply saying it is a property isn't really an answer explaining how the universe can be expanding without something occurring with the energy that comprises it to accommodate this expansion , either more of it or an expansion of existing. What I have read suggests more space-energy is created as the universe expands,which is what I was driving at.

 

As far as the conservation of energy, I have read someone, I don't know if it is Krausse or Hawking , say that the laws of relativity and thermodynamics  cannot be applied at the initial moment of the BB, as they break down. If this is so then does  this not  negate the conservation of energy as an explanation of why energy cant expand with the universe? The universe expands faster than the speed of light, so what limits us doesn't necessarily limit the universe.

Edited March 27, 2018 by wallflash

[Strange]

3 hours ago, wallflash said:

everything in the universe is moving away from everything else due to expansion from a single point

The “single point” comes from a naive extrapolation using GR. But we know our current theories can’t describe what happens before a certain point in time. It is assumed that a theory of quantum gravity will explain more about the earliest times, etc. 

1 hour ago, wallflash said:

 If the universe is comprised of energy, and the universe is expanding , is the energy that makes up the universe expanding or more energy-space being created ? How would the universe expand without one of these concepts being necessary?

Dark energy seems to be a property of space so, as space expands, total energy increases (if that’s what you mean).

Edited March 27, 2018 by Strange

[beecee]

Hmmm...OK, here's my 2 cents worth, as outlined to me long ago by an Astronomer.

The most important point I see is that the BB theory tells us that the universe/space/time [as we know them] evolved from a hot dense state, at a point t+10-43 seconds. Noting the high lighted parts, it can therefor be seen that this [the BB] applies to the observable universe, as detailed here.......http://www.astro.ucla.edu/~wright/infpoint.html  

"The Universe was not concentrated into a point at the time of the Big Bang. But the observable Universe was concentrated into a point. The distinction between the whole Universe and the part of it that we can see is important. In the figure below, two views of the Universe are shown: on the left for 1 Gyr after the Big Bang, and on the right the current Universe 13 Gyr after the Big Bang (assuming that the Hubble constant is H_o = 50 km/sec/Mpc and the Universe has the critical density.) 

The size of the box in each view is 78 billion light years. The green circle on the the right is the part of the Universe that we can currently see. In the view on the left, this same part of the Universe is shown by the green circle, but now the green circle is a tiny fraction of the 78 billion light year box, and the box is an infinitesimal fraction of the whole Universe. If we go to smaller and smaller times since the Big Bang, the green circle shrinks to a point, but the 78 billion light year box is always full, and it is always an infinitesimal fraction of the infinite Universe".

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

In my own mind, and in a way I believe can be best understood, I see this incredible story line like this.  Space and time, [as we know them] evolved with a tremendous impetus we have termed Inflation, in the first early incidents of time at around t+10-43 seconds. Since that time, and up until around 5 billion years ago, the gravity from the mass energy density of the universe [stars, quazars, BH's planets etc] acted to slow the expansion rate. Then gradually the constant impetus behind the actual expansion of spacetime, [that which we now term DE] is slowly over taking the effects that gravity was having in slowing this expansion rate, so that now, today, we actually see an acceleration in that expansion. [Remembering that this DE is consistent everywhere, and the density within the universe is lessening] 

Any errors, alterations, and/or corrections needed in that summary gladly welcome. But I believe it is put in a way [dumbed down if you like] that explains the BB/Inflationary model so that even I can understand it.

[MarkE]

7 hours ago, Silvestru said:

Can you provide a paper on this or a serious source?

The Zero-Energy universe is BS as far as I know.

LMGTFY.

8 hours ago, MarkE said:

The fact that there is energy in the first place, and that it is expanding

8 hours ago, Silvestru said:

Energy is not expanding.

I was referring to ‘the universe’ , not to 'energy', thanks for pointing that out, and excuse for being grammatically not clear enough. Energy itself isn’t expanding, a particle can’t expand, particles can however divide (which was the main point I was trying to make), and because they divide, the space between those particles expands.

A long time ago I’ve read this book called ’13 things that don’t make sense’. If I remember correctly, there was a quote in it that went something like “Dividing matter will generate less and less, but dividing energy will generate more and more”. I’ve always thought that this was an interesting idea. Maybe it’s true after all, even though it doesn't make sense.

[Airbrush]

"The Universe was not concentrated into a point at the time of the Big Bang. But the observable Universe was concentrated into a point."

Right, because the observable universe has a definite finite shape, a perfect sphere.  At the "time of the big bang" we don't know anything about the universe being a "point" right?  Would it be more proper to say the big bang started out with no definite shape, from a region of unknown size?