[Bill S (OP)]

I’ve tried on a number of occasions to get an answer to this, including in a recent thread.  Perhaps separating it from other material might do the trick.

Consider the statement: “The total amount of energy in the universe is zero.”
Are there two ways in which this could be interpreted? 

1.  There is no energy in the Universe.
2.  There is a specific amount of positive energy in the Universe.  There is also a specific amount of negative energy in the Universe.  These amounts are equal, therefore, the balance is zero.

In the case of our Universe, there is, manifestly, an energy content, therefore 1 cannot apply.

If 2 is the appropriate interpretation, although the positive and negative energies cancel each other, they cannot destroy each other; thus, there must be a difference between “zero energy” and “a zero balance of energy”. 

I’m prepared to acknowledge that my reasoning could be wrong, but I would appreciate knowing how/where.

[Colin2B]

Howabout we start with this:

There is the same amount of energy before the big bang as there is now. The total amount of energy in the universe is zero. That's how energy remain conserved as it was created. There's two kinds of energy; positive and negative. Negative energy comes from gravitational potential energy and positive energy comes from particles. You can read about it in The Inflationary Universe by Alan Guth. I can make those pages available to you if you'd like?

[Bill S (OP)]

Thanks Colin.

I started with that, and it all seems to have gone down hill from there. 

[yor_on]

Are you thinking of transformations Bill?
Entropy?

And how it can exist?

[jeffreyH]

During the big bang there was a period when there was only one force. This was a combination of the strong, weak, electromagnetic and gravitational forces. As the big bang progressed these forces separated out. The question to ask is what was the energy balance during this process and how does it relate to the current state of the universe?

[Bill S (OP)]

Are you thinking of transformations Bill?

No. I'm thinking: is there a difference between no energy and two lots of energy, each of which cancels  out the other, but both of which remain. 

  The question to ask is what was the energy balance during this process and how does it relate to the current state of the universe?

OK, so I asked the wrong question!  Does this mean that no one knows the answer to my question; there is no answer to my question; or, my question is so silly, it makes no sense to anyone other than me?

[geordief]

What is (an example of) "energy balance"?

Would it be kinetic energy versus potential energy?

In what sense can it be said that the energy balance of the universe (or any "closed" system) is zero?

@the OP is my "Why is energy observer dependent?" thread connected possibly?

[Bill S (OP)]

What is (an example of) "energy balance"?

There's two kinds of energy; positive and negative. Negative energy comes from gravitational potential energy and positive energy comes from particles.

I have no quarrel with this as an example of energy types that might balance.  I don't see it as answering the original question. 

[geordief]

I have no quarrel with this as an example of energy types that might balance.  I don't see it as answering the original question. 

Are you assuming energy is a "thing" rather than a property?

Just because it may be zero (on overall balance) does not mean that it is a property of nothing. (a misunderstanding of "energy is zero"?)

[jeffreyH]

Are you thinking of transformations Bill?

No. I'm thinking: is there a difference between no energy and two lots of energy, each of which cancels  out the other, but both of which remain. 

  The question to ask is what was the energy balance during this process and how does it relate to the current state of the universe?

OK, so I asked the wrong question!  Does this mean that no one knows the answer to my question; there is no answer to my question; or, my question is so silly, it makes no sense to anyone other than me?

No it wasn't the wrong question at all. I just extended it. There can never be just zero energy. Otherwise nothing exists. The energies can balance out. Imagine an object at its apex of a trajectory upwards in a gravitational field. The kinetic and potential energies balance. This does not mean that the energy of the object is gone. It still has rest energy.

[acsinuk]

If the fundamental energy in the universe were electrical then it could balance if the negatively charged matter balanced the positively charged stuff?

[PmbPhy]

No. There's no difference.

[geordief]

No. There's no difference.

Can you  make a (useful)  distinction between global energy and local energy?
Haven't got around to looking at your link yet...

http://www.newenglandphysics.org/physics_world/cm/what_is_energy.htm

[PmbPhy]

I was addressing his comment

1.  There is no energy in the Universe.
2.  There is a specific amount of positive energy in the Universe.  There is also a specific amount of negative energy in the Universe.  These amounts are equal, therefore, the balance is zero.

Which to me are sentences saying the exact same thing in two different ways. I don't know what you mean by global and local. Energy is energy. To me there's little difference in calculating the energy of a charge sphere (global) and that in an immediate area such as between the plates of a capacitor.

By the way. I hear that the person who wrote that page is a crackpot.

[geordief]

I don't know what you mean by global and local

Well, a small system  might have the energy of the interactions between its elements measured and the result  might sum up to  a positive or a negative amount ** depending on the frame of reference within the  system.

As the system is decreased in size and corresponding energetic measurements are made then the outcome might be described as "local" compared to the outcome if the system was increased in size infinitely (then it would be "global").

But then ,I think you may have correctly understood  my meaning judging that from your " charge sphere (global) and that in an immediate area such as between the plates of a capacitor" comment.

**eg potential energy would be the negative of kinetic energy ,perhaps.

[Bill S (OP)]

There can never be just zero energy. Otherwise nothing exists. The energies can balance out. Imagine an object at its apex of a trajectory upwards in a gravitational field. The kinetic and potential energies balance. This does not mean that the energy of the object is gone. It still has rest energy.

Thanks Jeffrey, that seems to say quite clearly that there is a difference between zero energy and a zero balance. 

[Bill S (OP)]

1.  There is no energy in the Universe.
2.  There is a specific amount of positive energy in the Universe.  There is also a specific amount of negative energy in the Universe.  These amounts are equal, therefore, the balance is zero.

Pete, I’m probably confused, but I have to ask if you are saying that statements 1 & 2 above are “saying the exact same thing in two different ways”. 

[jeffreyH]

There is a difference between the absence of energy and a balance of energy types. I think elsewhere @chiralSPO made the point that even at absolute zero there is still motion. The zero point energy. So that does make the distinction. If we ignore zero point energy then we are left considering a state without any relative motion between objects. Not a tenable position with the known forces.

[Bill S (OP)]

Not a tenable position with the known forces.

Consider the statement: “The total amount of energy in the universe is zero.”
Are there two ways in which this could be interpreted?

1.  There is no energy in the Universe.
2.  There is a specific amount of positive energy in the Universe.  There is also a specific amount of negative energy in the Universe.  These amounts are equal, therefore, the balance is zero.

In the case of our Universe, there is, manifestly, an energy content, therefore 1 cannot apply.

This was my "low-tech" way of expressing the same idea.

[jeffreyH]

If a concept is becoming complicated then it is losing its merit.