After reading the various answers to the question, I'm going to sneak through the door opened by Philip Anderson and nominate a discovery instead of an invention. And it is the Copernican Theory. Generally it was a counter-intuitive idea, and it ran opposite to the interpretation of senses (not to mention the Church) I mean, one could "see" the sun going across the sky. What could be more obvious than that? A nice move. It took a lot of intellectual courage, and taught us more than just what it said.
To arrive at the edge of the world's knowledge, seek out the most complex and sophisticated minds,
put them in a room together, and have them ask each other the questions they are asking themselves.