Originally Posted by eburacum45

I am not a cosmologist, so I can only give you the dumbed down version;
yes, the space inside our local group of galaxies is expanding, and the space inside the Earth, and inside atoms; but the expansion is very weak, so cannot overcome the forces which hold those objects together. Gravity, nuclear forces, and so on make sure that these objects do not expand in the same way that the Universe as a whole does.

I beleive that the expansion does actualy inflate atoms, the Earth, and the Local group slightly, so that they are larger than they would be if expansion didn't exist;but I don't think that has been measured (as far as I know). It is an incredibly small expansion on the scale of anything we can directly measure.