[Protagoras]

If we all agree that in a short time small changes can occur, then we must agree that in a long time, big changes can occur unless something stops them.

No we don't. You can posit that if you like, but it's not proof, nor scientific method.

We need to know what that something is and how it works.

Let me know when you do. I'm all for looking into things.

[crail]

If we all agree that in a short time small changes can occur, then we must agree that in a long time, big changes can occur unless something stops them.

No we don't.

Well small changes are observable. How could many small changes over a long time not add up to a large change?