Mr.Ziggety said 10 years, 7 months ago:

One thing that blows my mind is just the simple atom. Most of us know about the basic structure, protons clumped together with neutrons in between, but have you ever considered the amount of energy needed to keep that together? Protons are charged particles, and as such they repel each other. This repulsion force becomes exponentially more powerful as the protons get closer together, as explained by coulumbs law. So in order to have big bunches of protons stuffed together microscopically close to each other would take an enourmous amount of energy to overcome that repulsive force for even an instant. But somehow the neuclei of atoms all over the universe manage not to explode over millions of years. Where does this limitless amount of energy come from? It blows my mind.

timj said 10 years, 6 months ago:

The concept of strong nuclear force exerted by the neutrons that holds the nucleus together blows my mind. I am a chemistry teacher, not a nuclear chemist of physicist, so my understanding of this concept is limited. But it does blow my mind.