It's possible that we are all smaller now than at any specific point in the past. Just as space-time may speed up, slow down or, go up or down, unbeknownst to us, it can also shrink or expand.

It is probable that the mystery of Quantum Mechanics lies in the fact that sub-atomic particles are in-between two worlds. In that they are abiding by two separate laws, two separate realities, at the same time.

I assume though that as these particle are tied to you, if they are in another universe, the occupants there observe that they display odd properties (like dark matter possibly?)

Land of the Free, home of the Brave.