Cosmic expansion is not to blame for expanding waistlines
Unfortunately, physicists can explain why we can’t use cosmic expansion as an excuse for a spreading waistline.
If the force involved – electromagnetic in the case of atoms – binding the system together is stronger than a certain critical value, the system will be entirely unaffected by the cosmological expansion.
“This means that the solar system – which is quite tightly bound by gravity – doesn’t expand. Your desk doesn’t expand. Your dog doesn’t expand. But clusters of galaxies, which are only loosely bound by gravity, will feel this effect,” says Richard Price, a physicist at the University of Texas.