We have found it of paramount importance that in order to progress we must recognize our ignorance and leave room for doubt. Scientific knowledge is … - Richard Feynman

Scientific knowledge is a body of statements of varying degrees of certainty — some most unsure, some nearly sure, none absolutely certain.

that in order to progress we must recognize our ignorance and leave room for doubt.

"I suddenly remembered that Murray Gell-Mann and I were supposed to give talks at that conference on the present situation of high-energy physics. My talk was set for the plenary session, so I asked the guide, "Sir, where would the talks for the plenary session of the conference be?"

"Back in that room that we just came through."

"Oh!" I said in delight. "Then I'm gonna give a speech in that room!"

The guide looked down at my dirty pants and my sloppy shirt. I realized how dumb that remark must have sounded to him, but it was genuine surprise and delight on my part.

We went along a little bit farther, and the guide said, "This is a lounge for the various delegates, where they often hold informal discussions." They were some small, square windows in the doors to the lounge that you could look through, so people looked in. There were a few men sitting there talking.

I looked through the windows and saw Igor Tamm, a physicist from Russia that I know. "Oh!" I said. "I know that guy!" and I started through the door.

The guide screamed, "No, no! Don't go in there!" By this time he was sure he had a maniac on his hands, but he couldn't chase me because he wasn't allowed to go through the door himself!"

"In its efforts to learn as much as possible about nature, modern physics has found that certain things can never be "known" with certainty. Much of our knowledge must always remain uncertain. The most we can know is in terms of probabilities."

I don't know anything, but I do know that everything is interesting if you go into it deeply enough.