What Would Happen If the Earth Were Made of Protons and the Moon Were Made of Electrons

As part of their ongoing “What If?” series, Randall Munroe of xkcd and Henry Reich of MinutePhysics answered the very specific question about what would happen if the Earth were entirely made of protons and the moon were entirely made of electrons. The long answer is that electron moons cannot orbit proton planets, as the negatively charged electrons would bounce off of one another.

This is, by far, the most  destructive What-If scenario to date. You might imagine an electron Moon orbiting a proton Earth, sort of like a gigantic hydrogen atom. …However, electron moons do not orbit proton planets: if you put two negatively charged electrons together, they try to fly apart with a force about 20 orders of magnitude stronger  than the gravity pulling them together.

The shorter answer is that the entire universe would be sucked into a great big black hole.

There’s a huge amount of potential energy in this   scenario – the energy that we imagined  would blast all these electrons apart. That energy warps space and  time just like mass does.,,,,Would the attraction of this  universe-mass black hole cause the rest of the universe to collapse? Hard to say.