What Happens if Two Universes Collide?

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While there is no compelling evidence to suggest that there is more than one universe, there are premier physicists who plausibly suggest that there are.  These suggestions (they might be called hypotheses) are based primarily in mathematical interpretations, or extensions, of accepted physical theories, most notably, of quantum mechanics.  Collectively, these extensions are known by such names as the Many Universes Theory, or, Multi-Verse Proposal, among others.

Some of the projections from the Many Universes Proposal include the idea that, among an infinite number of universes, “Everything that can happen, must happen, and must happen an infinite number of times.”  While that idea has some glaring problems, the fact that it is spoken by premier physicists indicates that the theory enjoys great intellectual repute.

One of the open questions arising from the proposal is the question, can universes collide, and if so, what is the result?

The significance of the question is vastly more than at first meets the eye.  It is not as simple as if two ships were colliding, or even two continents.  A more apt analogy would be that of two volatile, dissimilar molecules colliding, or perhaps even more dramatically, the collision of a particle with its anti-particle counterpart.

In order to better appreciate this significance, we should remember that an important part of cosmological theory involves the randomness of the physical constants which define a universe.  All the properties of our universe are expressible in the mathematical values of such constants as the speed of light, the strength of gravity, the nuclear forces and so forth.  Alterations of any of these, particularly the most sensitive of them, would radically affect the stability of the universe.

Therefore, if two universes collide, and if they have large enough differences in their constants, the result could be the destruction of both universes—or at least changes in them that would result in chaotic disruptions.

Even more peculiar results could occur if the two universes have not only different values of their constants, but actually different constants entirely.  While our universe is said to have twenty-seven fundamental constants, what would happen if we collide with a universe that has more than that, or fewer?  What if the other universe has no gravity?  Or if it has forces that do not exist in our universe?

Finally, there are questions which may have no discernible meaning, such as, what exists (if anything) between universes?

Do we even have a framework for considering such questions?

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