Where did the universe come from? Atheistic origin science has no answer.

[Alex K]

I did not say virtual particle pairs and physical constants were the same. I was using an analogy. The point is that virtual particle pairs are allowed to exist because they add up to zero. (I am simplifying the borrowed energy aspect but the end result is still no net gain or loss of energy.) If all possible universes exist there would be a balance of opposites adding up to no net imbalance. Assuming the ‘all possible universes’ scenario violates no conservation rules.

Then make it "behave analogously".

 
String theory in general is still hypothetical and the news from the LHC is not encouraging. But we are already very far out on the hypothetical limb, so what the hell!
 

The idea that the LHC can somehow prove or disprove superstring theory is largely hype in my opinion. If we find supersymmetry, we've found supersymmetry. Just because it historically was coinvented in the context of the superstring doesn't mean that it needs superstrings - it works just fine as a standalone. But I just brought up string compactifications as a concrete example where people have looked at the spread of parameters in a multiverse, to illustrate that such scenarios, in the examples that are known, have no need for the measured physical constants to cancel out. I'm not aware of a realistic field theory where there's a viable symmetry of taking all constants to their negative value.

A general feature of M-theory constituents is dualities. In S-duality, strong interactions in one theory are weak interactions of different particles in another. In T-duality, a small radius of a compactified dimension is equivalent to a large radius. Ultimately compactified dimensions are thought of as embodied in a Calabi-Yau manifold. (Non-techie readers, imagine hyperdimensional swiss cheese. Sort of.) The mirror symmetry idea has it that different Calabi-Yau manifolds can yield the same results. It is not results that necessarily appear in opposite forms, but the underlying reality

That's right. Those are symmetries acting on the higher dimensional space and the string states, not the physical constants in the low energy theory.

BTW, imagine a universe in which the sign of mass-energy (non-virtual) is negative instead of positive. To a resident of such a universe could the difference be noticeable?
 

It depends what you mean. In special relativity, the mass shell condition E^2 =c^2 p^2 +c^4 m^2 allows a negative energy branch. Those are the tachyons, and they would look very differently.