If you tried reading those words and succeeded, you can speak German pretty well. These words were spoken by a very famous person, about the topic I am about to deliver!
Einstein thought entanglement was a "spooky action from a distance". This is also the idea that he played with until his passing. He thought it was so impossible that if he didn't find the truth of the matter, he would change professions.
At the basics, entanglement is very simple. 2 subatomic particles can "share information". Here's where Einstein got angry. The mathematics show that at any distance, the "information" is sent instantaneously. That is, faster than the speed of light (that was precisely when Einstein stopped making hair appointments).
Remember that I said "electrons are weird little buggers"? Well, there are smaller subatomic particles. Let's say, sub-subatomic particles. These wee things that make up the other wee things (smaller building blocks for the neutrons, protons and electrons). These are leptons, quarks and bosons. Bosons are the force particles aka the particles that help hold atoms together. Quarks are the fundamental masses of the subatomic particle. Leptons are what gives a subatomic particle its spin.
It's weird to think about but all subatomic particles have a spin to it. Scientists have actually given it a numerical value of 1/2 or -1/2 (up or down). The spin of the particle is what information is sent. (A bit of romance ahead) Each subatomic particle has a counter part somewhere in the universe. They are "related" to each other. If an electron has spin up, then its counterpart has a spin down value to it.
That doesn't sound to weird, so why did Einstein freak out? Say these particles were separated to either side of the universe, what do we have? We have one spin up lepton on the far left (for visual purposes) and one spin down to the far right. If the spin changes (which it can) than the other changes to oppose it, instantly.
This concept has helped the idea of quantum teleportation. Scary to think that we could travel faster than the speed of light. But in order for us to travel quickly, we need to build a "holding" bin to put the opposite spinned subatomic particles in.
I hope you have enjoyed my 3 part series on Quantum Mechanics. Any and all comments and questions are welcome. As always if you have an idea for this blog, don't be afraid to tell me, via comments as well.