Here I go again. All ready to show my ignorance. I don't necessarily agree that energy requires containment. After all if you set off a stick of dynamite in a vacuum there is no containment for the energy released.
Then of course energy can provide its own containment. After all energy and mass are interchangeable. So a quantity of energy can generate a gravitational field that will contain the energy. This of course is a problem that I always had with the Big Bang Theory. With the entire mass of the universe contained in a point source, how did it start expanding? It seemed that the gravitational attraction of the mass should have contained the universe. That may be fixed by the idea of dark energy. It seems there is much more dark energy than there is normal(?) energy.
Containment requires forces which is my basic problem with Bill's conjecture that at the start of the universe we just had a bundle of energy ... you could not have that energy as a bundle without the containment forces in place else it would have exploded or imploded.
Well, at the start of the universe the energy that became the universe did explode, so I don't see a problem with that.
And on top of that we really have no idea what happened immediately after the start of the expansion of the universe. In the first few microseconds the energy density was so high that our current physics has no way to handle it. It is only after the Inflationary Period that things got cool enough for us to understand what happened.
Now I think I have driveled on long enough. I also seem to have kind of drifted around in what I had to say.
Bill Gill
