Einstein’s Nightmare
Albert Einstein called quantum entanglement “spooky action at a distance” because he didn’t believe it could be real. He was wrong—it is real, and it’s one of the most verified phenomena in physics.
What is Entanglement?
When two particles become entangled, measuring one instantly affects the other, no matter how far apart they are. Change the spin of one photon in New York, and its entangled partner in Tokyo changes simultaneously.
This happens faster than light could travel between them.
The Math
|Ψ⟩ = 1/√2 (|↑↓⟩ - |↓↑⟩)
Two particles in perfect anti-correlation: if one spins up, the other must spin down.
Real Applications
- Quantum teleportation - transferring quantum states across space
- Quantum networks - the future internet
- Fundamental tests - proving quantum mechanics is real
The Mystery
No one truly understands how entanglement works. We can use it, measure it, and rely on it—but the mechanism remains one of physics’ deepest mysteries.
The universe is connected in ways we’re only beginning to understand.