6. The Relative Strength of Electricity and Gravity

Electricity is stronger than gravity. The entire mass of the earth is exerting its best gravitational efforts to pull that object down, yet the small amount of static electricity you have generated defeats those efforts. It is a good thing because it enables life to exist. If electricity were weaker relative to gravity than it actually is, this would be more difficult. It's possible that evolution could produce a way for life to adapt to such a circumstance.

5. The Schwarzschild Radius

Einstein put forth his relativity theory to explain black holes in the form of a system of equations which were extremely difficult to solve, but Schwarzschild managed to find a solution to them in the midst of a war. Not only that, but he also showed that for any given quantity of matter, there was a sphere so small that if all that matter were packed inside it, it would become a black hole. The radius of the sphere is known as the Schwarzschild radius.