I’m still looking for the origin of momentum.
The universe is a zero sum game with momentum. All the local momentums add up to zero.
So it’s easy to see that as with light, from the point of view of the universe as a whole, nothing has overall been lost or gained overall by the creation of momentum.
However, unlike light, which is without mass, time, space, or motion (from its point of view), the universe has gained all four: mass, time, space and motion, the components of momentum.
This really matters to us. I mentioned earlier the Platonic principle that no part of a whole can perceive the whole. In order to do that, the part would have to be outside the whole, and then it wouldn’t be part of it. And the whole wouldn’t actually be the whole if something could be outside it.
We don’t care that what we see adds up to zero, because what we see are parts, and parts are definitely NOT zero.
But where did it start? Why are there parts at all? Where did momentum, the stuff of the universe, begin?
The Heisenberg Uncertainty Principle of Quantum Mechanics has an interpretation that offers an explanation that appeals to some theorists. Heisenberg discovered that there are pairs of attributes in the universe that have the unusual relationship that both cannot exist precisely together. One of these pairs is the qualities of momentum and position. A mass cannot have a precise position and a precise momentum at the same time. The relationship is even more troubled than that. If one is determined precisely, the other becomes undefined. It both doesn’t exist and it exists in all possible ways.
I need to make sure I’m clear here. This isn’t just a measurement problem in the normal sense, though that is involved. It’s not that the two really have precise values at the same time, we just don’t know them. They really can’t exist precisely together. As long as we know both only approximately, both exist—approximately. In our large scale inexact world, we can only know things approximately anyway, so we don’t have a problem.
So the argument for the origin of momentum says (roughly) that since 0 momentum and 0 position are exact quantities, that’s not a possible state. In other words, not existing is not allowed. And of course once one of these exists approximately the other also exists approximately, AND the momentum created has to come in pairs that cancel each other out, so the total momentum of the universe is always zero. (Note that the Uncertainty Principle functionally applies only to tiny individual masses, not to larger congregates, which is all we deal with on a daily basis.)
Physicists use this idea in our existing universe to explain some really arcane, but fundamental behaviors in the universe. Because of the uncertainty principle, it’s proposed that “empty” space is actually a boiling mass of particles being created and annihilated constantly at energy levels and in time spans so small that they never break through the threshold of Uncertainty Principle approximations into our observable universe. For QM physicists, this has to be true. It’s required by the science, and assuming it is true makes explaining some things easier, but of course, by definition, it can’t be observed.
So is that the answer? Momentum spontaneously begins out of null-where/null-when/null-thing, and the universe exists because not existing is an unstable condition and isn’t allowed by the laws of physics?
Physicists are rolling their eyes now at the gross oversimplification of that conjecture, but still, we have to start somewhere philosophically. One more blog!