spocktorwho

We use Newtonian equations when quantum effects can be ignored because they are so small. So technically it would be wrong, but it's good enough for that certain problem.

Well that depends on your definition I guess. If you mean reversing gravity, then your right, gravity is just (as we currently understand it) attractive. There are other means to defy gravity though, but when I jump I don't confused it anti gravity. Counteracting gravity, setting up a system where the effects of gravity are counteracted compleatly by some other force, could be called anti gravity.

I should explain that I don't have any modeling project in mind, per se. I just want to learn something that would be adaptable to future use. I've heard of C and python, and got a recommendation of Java from a friend of mine...

What's R, klaynos?

Don't start with Java. Java is an object-oriented language and is very complex. I wouldn't suggest it to start, but C and Python would be good starters.

There's no such thing as anti-gravity. Gravity is a purely attractive force.

None of Newton's work had much (if any) to do with electrons, but he did predict that light was made of particles.

1. To my understanding, only if it is a quantum particle, like an electron or a quark.

2. We don't know.