universe seems expanding, scientist say. is it happening in quantum level or only stars n planets n heavenly bodies r separating?? if it is happening in quantum level then all the particles like molecules, atoms, nucleus, protons, quarks.... r separating resulting in uniform expansion on EVERYTHING. so does it really effects the size of universe??

is expanding really the best word to describe what is happening to the universe?

We do observe galaxies moving away from us so expanding on a universe level sounds ok to me. But on a quantum level or even a galaxy level there is no observed expansion.

 

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I am no expert in this area, but my understanding is thus; the expansion happens on scales where there is no greater opposing force, on galactic scales this is gravity, all the way down to atoms where EM is too strong for the expansion to override it. And further down the strong and weak interactions are too strong.