system
Given the following post, respond as if you're commenting on Reddit:
human
Were superconductors theorised first or discovered?

The title say it all really.

Were they mathematically predicted first or just discovered by accident or similar?
gpt
In the early 1900s, there were competing theories about what would happen if a sufficiently pure metal were lowered towards absolute zero. Some thought that the trend of lower resistance would continue all the way down, others that electrons would become immobile and resistance would increase towards absolute zero. Heike Kammerling-Onnes tried to test this using mercury, which was easier to purify than solid metals. He found something totally unexpected, that the resistance didn't just smoothly decrease, but that there was an abrupt drop to zero at around 4 kelvin.