So I’ve been reading Alan Turing’s biography by Andrew Hodges and find myself glued to the pages. Sadly, I suck balls at math (no pun intended). I truly do. It’s the subject that ruined my otherwise perfect GPA in high school. I’ve been trying to grasp some of the concepts mentioned in the book, and quantum mechanics is one of them. This is fascinating! I never saw that before. I mean I heard the words thrown around but I never understood what it meant. I guess I still don’t. I would love to go back to school and start all over and actually pay attention in physics, maths and chemistry. Anyway, there’s this thing on reddit, ‘explain it to me like I’m five years old’, and anyone who has ever done this properly will probably scream in protest, but it’s ok to dumb it down a bit to get across the idea to non-pros (hey, Stephen Hawking agrees!).

There seem to be a lot of people responding who overestimate the vocabulary of a five-year-old. Here’s my best shot at speaking to a kindergartner.

Physics is how we try to figure out what happens when we throw a rock at another rock. It’s pretty easy to see that throwing a small rock at a big rock is different from throwing a big rock at a small rock. One day, somebody got tired of playing around with big rocks and started using the smallest rocks he could find and throwing them at each other. These rocks were so small that you can’t see them with your eyes, you have to use other tools to know what they’re doing, kind of like when an ant bites you or a bee stings you, you can’t see what they did but you know they did something because it made your arm hurt. Even though they couldn’t see the rocks, they knew what was happening because the tools they made showed them, just like your arm tells you when you get stung/bitten.

So the next thing this guy did with his very tiny rocks was to launch them through a very thin hole at a sheet and see what happened when they came out of the other side. Most people would probably guess that tiny rocks that are shot through a tiny opening will make a tiny hole in the sheet. But that’s not what happened. The tiny rocks spread out once they went through the tiny hole and they wanted to go through the sheet more easily in some places than others. But this only happens when you use small enough pieces of rock. The big pieces of rock don’t act like that. We’re still trying to figure out why.

Some also posted this link to a video of the double slit experiment (which I found very helpful since I’m a visual learner):