Quantum Physics (or Quantum Mechanics) is the study of why shit happens at a mind-blowingly small level. You know the amount of sympathy you had for Winona Ryder when she was picked up for shoplifting? Yeah, even smaller.
Albert Einstein was a smart mother fucker. He was the Shaft of theoretical physics. If anyone disagrees with that statement, this guy will be waiting for you out in the parking lot:
Feel lucky, punk?
Well, Einstein proposed a theory while working in a Swiss patent office that piledrived Newtonian physics in the wrestling ring of science, General Relativity. For the readers that had physics teachers with immaculate busts, the General Relativity defined previously unknown ideas about gravity, the speed of light, time, and dimensions of space-time. Unsatisfied with shattering the previous notions of gravity, Einstein immediately began to work on unifying his new picture of gravity with the only other force known at the time, electromagnetism. Enter, Scottish Physicist and Mathematician James Clerk Maxwell (well, 50 years prior).
Before James Clerk Maxwell, scientists knew that Electricity and Magnetism were connected, but didn't understand how to articulate their relationship mathematically (although Magnetism's facebook listed their relationship as "It's Complicated"). Maxwell entered the scene and said, in a rough Scottish accent, "Enough of this bullshit" and broke down the relationship between Electricity and Magnetism into four, all-encompassing equations that completely defined how electromagnetism behaved. Maxwell then proceeded to eat under-cooked red meat, liberally apply facepaint, and moon the army of Edward the First of England, as portrayed by Mel Gibson's blockbuster, Braveheart.
James Clerk Maxwell, as portrayed by Mel Gibson
Einstein soon found that even though gravity and electromagnetism traveled at the speed of light, that was nearly all they had in common. Electromagnetism turns out to be far stronger than gravity, comparitively. This explains why you don't fly to the center of the earth every time you tumble down the stairs at the end of a drunken night. The electromagnetic force of the electrons in your face repelling the electrons in the base of the stairs is stronger than gravity. In fact, the electromagnetic force is billions of times stronger than gravity, a fact Magneto often uses to pad his resume.
He really wants that CBS internship.
Soon after Einstein began the nearly impossible job of unifying electromagnetism and gravity, a new group of scientists, which included Max Planck, Niels Bohr, Werner Heisenberg, Erwin Schrodinger, Louis de Broglie, Max Born, and others, presented a brand new way of thinking about physics, Quantum Physics. Originally theorized by Max Planck, Quantum Physics presented 2 more forces, the Weak Nuclear force and the Strong Nuclear force, which added to Gravity and Electromagnetism. This theory explained how atomic and subatomic partles behaved, the relationship between the forces in the subatomic world, and why there are so many songs about rainbows.
Renowned physicist, Kermit T. Frog
A fundamental tenet of Quantum Physics is the idea that all matter and energy behaves as both a wave and a particle. This is known as Wave-Particle Duality, or the "Shit is All Over the Place" Theory. In layman's terms, the fundamental building blocks of everything in the universe travel as waves, but depart and arrive as particles. They do not, however, travel by means of waves, as described by the Johnny Tsunami Theory.
Wave-particle duality causes some scientific paradoxes due to superpositions. One famous thought experiment was proposed by Erwin Schrodinger. A cat is placed into a box, Dr. Seuss style, along with poison, a hammer, a Geiger counter, and a small amount of radioactive material. The original experiment called for MacGyver instead of a cat, but he kept escaping using the items in the box.
Fuck you, physics, I'm out of here.
The radioactive material has a 50% chance of decaying, setting off the Geiger counter, activating a relay, releasing the hammer, cracking the poison bottle, and killing the cat. If the atom doesn't decay, the killer Rube Goldberg machine does not fire, and the cat is alive. Based on the Copenhagen interpretation of quantum physics, the cat is both alive and dead at the same time until the box is opened and the cat is observed. In the Many-Worlds interpretation, both results of the experiment happen, but are decoherent - meaning there are 2 parallel universes, one in which the cat is alive and one in which he is dead. If the Many-Worlds interpretation is correct, there is an infinite amount of parallel universes containing all possible outcomes of all possible decisions in the history of the universe. That means there is at least one universe where Wilt Chamberlain has fucked exactly zero women.
Alternate Wilt "The Stilt" Chamberlain, displaying what percentage of the day he spends dreaming of actually having sex with a woman.