The past few weeks have featured a few stories about how Albert Einstein’s theories, or the ideas underpinning them, have all been confirmed to a new degree of accuracy. That’s usually the case: Scientists try to disprove Einstein, and Einstein always wins.

But that’s not to say the man was infallible. He was human, just like the rest of us, and did make some mistakes. Here’s a few of them.

1) The cosmological constant
When he was crafting his theory of gravity, general relativity