Kurzgesagt’s “Quantum Computers Explained”

Published by whurley (03/24/2017)

Hands down the best video explanation of quantum computing on the Internet.

When someone asks me about quantum computing–what it is, how it works, where they can learn about it–I like to start them off with this video. I think it’s the best to date on the subject. Also, these guys are fun and engaging, and the animation is solid. Kurzgesagt makes getting your head around quantum computing as easy as it can be. After watching “Quantum Computers Explained – Limits of Human Technology,” you’ll understand the basics. If you need more than that, stay tuned to this blog in the future.

The video starts with a short, amusing history lesson on technology in general (our “brain machines”). It explains how classical computers work–circuits, basic modules, logic gates, and transistors. Then it covers our current situation. Computers have been getting smaller and faster at a predictable rate. As part of that, transistors have been getting smaller.  Like really small.  Smaller than a virus.  The new SnapDragon processor contains 30 billion of them (with a “b”), and it powers the five-inch phone you have in your pocket right now.


But we’re about to hit a physical limit to the size of a transistor. Namely, the size of an atom. As things get smaller and smaller, we approach the scale where quantum mechanics come into play. Weird things kick in, like quantum tunneling. Quantum tunneling means that at the atomic level, particles like electrons can go through barriers that otherwise would  have prevented their passage.  In other words, a transistor that small might not be able to do its job of stopping the flow of electrons. It simply wouldn’t work.

Watch the video to pull that string. Trust me. If you’re interested in quantum computing it will be worth your 6 minutes and 45 seconds.