system
Given the following post, respond as if you're commenting on Reddit:
human
Why is Gravity still considered a theory, and will Evolution always be one too? When/How does "theory" get dropped from the title? thanks.

thank you in advance for your answer.
gpt
There are really three relevant words here, so I'll provide the definitions of all of them.

A hypothesis is basically an educated guess. When most people say theory, they mean hypothesis. It's something that's gotten into our everyday vocabulary, which is somewhat unfortunate since it can cause people to misinterpret what a theory is.

A theory is a hypothesis or a summary of a group of hypotheses that have been repeatedly supported. Something that is a theory has been supported a large number of times, and there is not solid, peer-reviewed evidence against it. 

A law is also something that has been supported repeatedly, but the main difference between it and a theory is that it is a summary of observations, not of hypotheses.  It doesn't explain why something happen, it just states that it does. It's a law that the universe seems to follow. 

Hopefully these definitions provide an adequate explanation of how these terms get used, and of why evolution is a theory, and why it will continue to be. Saying "It's just a theory" is something that's made it's way into public use, but in science, that's something that's basically nonsense to say. A theory is quite weighty.