Physics vs. Engineering

As I read this column about quantum cryptography, I was struck by the difference between physicists and engineers.

Physicists like quantum cryptography, teleportation and computing because they're interesting. Using lasers to transport electrons across space, creating an unbreakable code, and light-powered computers that can crack any classical code in the world are awesome. Sure, the most complicated quantum computers in existence can barely manage to count your fingers AND toes, but the idea is still cool.

From the engineering side, though, quantum teleportation is a useless trick. Like quantum computing, it only works with a handful of particles, and until you can operate with the millions (or googols) of particles it would take to be useful, it's just a weird trick.

While quantum cryptography works now, it's unnecessary. Classical cryptography is strong enough, because getting someone to give you their password is easier than cracking either code. So a code that's mathematically impossible is functionally the same as one that's really really hard. And since it's way more expensive, it's useless.

But since I'm a physicist, I still think it's cool.