[juggernot]

This question may be completely ridiculous, so I will start this post with a warning. I'm not a scientist by any means, so I apologize for my ignorance. To be clear, when I say the universe I simply mean the total area that matter and energy occupy. From what I understand, the big bang catapulted matter out into space and it has been moving through it ever since. I've heard recently that empty space or 'vacuum' actually has energy. At the very least a vacuum has pressure, even if it is negative pressure. I assume then that all empty space is exherting a force on all matter. In other words, the earth is being tugged at by the negative pressure of empty space? Is this correct?

The following is a couple of follow up questions. If I have made a false assumption earlier the following questions will be void.

-If empty space exherts a force on matter, is it possible that the big bang was actually a big pull? That the force of empty space ripped pieces of matter away from the gravitational singularity?

-From what I understand we have an infinite amount of empty space exherting forces on us. Is there anyway this force can 'theoretically' be harnessed to do work?

Thanks for your help.

[Pluto]

G'day from the land of ozzzzzzz

If the Big Bang originated from a singularity being a Black hole. Than nothing could have made it eject matter away from it, not even a super vacuum.

So there had to be some form of mechanism, to eject matter away.

The mechansim must have :
1) Ejected degenerate matter that formed our normal matter.
2) The ejected matter must have had a protection of some form to not be effected by the extreme gravitational pull of the BH.
3) That this process occured everywhere at the same time and not in one spot.

I do not agree with the above, that does not mean that I'm right.

[modest]

Originally Posted by juggernot

From what I understand, the big bang catapulted matter out into space and it has been moving through it ever since.

The universe isn't necessarily expanding into anything. The Big Bang isn't "matter being catapulted into space." Nasa's page on the Big Bang explains:

Please avoid the following common misconceptions about the Big Bang and expansion:

• The Big Bang did not occur at a single point in space as an "explosion." It is better thought of as the simultaneous appearance of space everywhere in the universe. That region of space that is within our present horizon was indeed no bigger than a point in the past. Nevertheless, if all of space both inside and outside our horizon is infinite now, it was born infinite. If it is closed and finite, then it was born with zero volume and grew from that. In neither case is there a "center of expansion" - a point from which the universe is expanding away from. In the ball analogy, the radius of the ball grows as the universe expands, but all points on the surface of the ball (the universe) recede from each other in an identical fashion. The interior of the ball should not be regarded as part of the universe in this analogy.
• By definition, the universe encompasses all of space and time as we know it, so it is beyond the realm of the Big Bang model to postulate what the universe is expanding into. In either the open or closed universe, the only "edge" to space-time occurs at the Big Bang (and perhaps its counterpart the Big Crunch), so it is not logically necessary (or sensible) to consider this question.

Originally Posted by juggernot

I've heard recently that empty space or 'vacuum' actually has energy. At the very least a vacuum has pressure, even if it is negative pressure. I assume then that all empty space is exherting a force on all matter. In other words, the earth is being tugged at by the negative pressure of empty space? Is this correct?

Vacuum energy is revealed as the cosmological constant in general relativity. It is part of gravity. If there are two large bodies such as the Milky Way and the Andromeda galaxy then there is some interaction between them, pulling them together, which is gravity. The cosmological constant (or vacuum energy) lessens the force of gravity between them. They still pull on each other, but the attraction is just a little less. Without the cosmological constant, gravity would be:

and with it, we have another term on the right, it's a negative term meaning it's a repulsive effect,

But gravity is still attractive overall.

Originally Posted by juggernot

If empty space exherts a force on matter, is it possible that the big bang was actually a big pull? That the force of empty space ripped pieces of matter away from the gravitational singularity?

This assumes that there was something outside the singularity pulling on it. But, cosmology doesn't make that assumption. We assume the singularity is the whole universe. Any empty space, or any vacuum energy would be inside the singularity as part of our universe.

Originally Posted by juggernot

From what I understand we have an infinite amount of empty space exherting forces on us. Is there anyway this force can 'theoretically' be harnessed to do work?

This is a common question, as wiki says:

The existence of vacuum energy is also sometimes used, outside of mainstream physics, as controversial theoretical justification for the possibility of free energy machines. It has been argued that due to the broken symmetry (in QED), free energy does not violate conservation of energy, since the laws of thermodynamics only apply to equilibrium systems. However, consensus among particle physicists is that this is incorrect and that vacuum energy cannot be harnessed to do usable work. In particular, the second law of thermodynamics is unaffected by the existence of vacuum energy.

Vacuum energy - Wikipedia, the free encyclopedia

You also might enjoy the thread SNe Ia, Implications, Interpretations, Lambda-CDM...

~modest

[Pluto]

G'day from the land of ozzzzzz

Modest said

We assume the singularity is the whole universe. Any empty space, or any vacuum energy would be inside the singularity as part of our universe.

I think you have me confused.

Please explain

[modest]

Originally Posted by Pluto

I think you have me confused.

Please explain

Sure Pluto.

The misconception is here:

Originally Posted by juggernot

If empty space exherts a force on matter, is it possible that the big bang was actually a big pull? That the force of empty space ripped pieces of matter away from the gravitational singularity?

The idea has the singularity as a point in space. Matter or energy is pulled out of the singularity by vacuum energy and it expands away forming the universe.



In BBT, nothing leaves the singularity. Nothing is pulled or pushed out of it into the rest of the universe, because the singularity was the whole universe. Thinking that the singularity was a spot somewhere in space and expanded into space is a common misconception that is addressed in most all introductory texts on the big bang.

It's best thinking of the universe like an infinity large rubber band. If we zoom into a very small section of this rubber band and pretend there are some business people hanging about on it - we might say these people represent galaxies:

If the rubber band is stretched then the folks on it notice everybody getting further away.

The rubber band is the universe. When it was very small it was a singularity. Nothing ever left the rubber band to expand away from it - we are still on it. We are still part of the thing that was the singularity and it is still expanding. It doesn't (as far as we know) expand into anything.

~modest

[Pluto]

G'day modest


I thought that a singularity was an infinite small spot.

[modest]

Originally Posted by Pluto

I thought that a singularity was an infinitely small spot.

I don't know why you're saying this or what it has to do with my post above, but I'll comment on it.

A closed universe is not infinite. It has a limited amount of content. It will not expand forever. It will eventually contract back to a singularity. A flat or hyperbolic universe is infinite in size and presumably infinite in content. The evidence so far suggests that our universe is flat... and therefore infinite. This makes your question difficult to answer. Can an infinitely large size exist in an infinity small singularity?

A quote from "The Matter Myth", 1992:

I suppose infinity always dazzles us, and I have never been able to build up a good intuition about the concept. The problem is compounded here because there are actually two infinities competing with each other: there is the infinite volume of space, and there is the infinite shrinkage, or compression, represented by the big bang singularity. However much you shrink an infinite space, it is still infinite. On the other hand, any finite region within infinite space, however large, can be compressed to a single point at the big bang. There is no conflict between the two infinities so long as you specify just what it is that you are talking about.

I think this is the typical scientific answer, but I don't find it too satisfying. Two things we can say for sure without invoking the problem above:

1. The visible universe was an infinitely small singularity
2. The universe's mass used to be infinitely close together

But this is not related to my post above. No matter what size the primordial atom was - nothing left it. It was not a spot in space from which everything exploded out.

In our universe, as on the surface of the balloon, everything recedes from everything else. Thus, the big bang was not an explosion in space; it was more like an explosion of space. It did not go off at a particular location and spread out from there into some imagined preexisting void. It occurred everywhere at once.

If one imagines running the clock backward in time, any given region of the universe shrinks and all galaxies in it get closer and closer until they smash together in a cosmic traffic jam--the big bang. This traffic-jam analogy might imply local congestion that you could avoid if you listened to the traffic report on the radio. But the big bang was an unavoidable traffic jam. It was like having the surface of Earth and all its highways shrink while cars remained the same size. Eventually the cars will be bumper to bumper on every road. No radio broadcast is going to help you around that kind of traffic jam. The congestion is everywhere.

Similarly, the big bang happened everywhere--in the room in which you are reading this article, in a spot just to the left of Alpha Centauri, everywhere. It was not a bomb going off at a particular spot that we can identify as the center of the explosion. Likewise, in the balloon analogy, there is no special place on the surface of the balloon that is the center of the expansion.

Misconceptions about the Big Bang: Scientific American

~modest

[Pluto]

G'day modest

I' starting to understand your logic of thinking

You said

I think this is the typical scientific answer, but I don't find it too satisfying. Two things we can say for sure without invoking the problem above:
The visible universe was an infinity small singularity
The universe's mass used to be infinity close together
But this is not related to my post above. No matter what size the primordial atom was - nothing left it. It was not a spot in space from which everything exploded out.

I understand what you say, it does not mean that I agree with it.

The problem I have is "TIME".

Did the BB occur at the same time? Varies spots as per the link
Misconceptions about the Big Bang: Scientific American


Will it go back to a point at the same time?

[Eclogite]

Just as the Big Bang created space it also created time. I don't understand what you mean by did the BB occur at the same time: the same time as what? Anyway in a relativistic universe 'the same time' has no real meaning, as I understand it.

[Pluto]

G'day eglogite

You said

Just as the Big Bang created space it also created time. I don't understand what you mean by did the BB occur at the same time: the same time as what? Anyway in a relativistic universe 'the same time' has no real meaning, as I understand it.

Space and time are two items that cannot be changed, because they do not have any FORM, thefore cannot create.

Please read Modest comments on the BBT.
Misconceptions about the Big Bang: Scientific American
Misconceptions about the Big Bang: Scientific American

Re: BB occuring at the same time throu out the universe.