When do you know you have understood physics?

[ipsky]

This is rather a philosophical question, so I will limit it to a topic in physics. I'm interested in knowing your opinion, and perhaps your thoughts on how physics is being developed and progressed today.

 

[fresh_42]

I voted with Feynman:

"If you can't explain something to a first year student, then you haven't really understood." ~ Richard P. Feynman

 

[hutchphd]

For me (internally), it is when I believe I can walk in front of an audience at any level of sophistication and explain the topic at hand. Pretty close to the Feynman attribute.
I do however know that know nothing.

 

[russ_watters]

How much of physics? These days nobody can know all of it.

 

[kyphysics]

“What I cannot create, I do not understand.”
-Richard Feynman (one of two quotes scrawled on his blackboard discovered after his death)

He seemed to mean you should be able to break a topic down and "recreate" it from scratch in your own words/understanding and build it back up to explain to someone. You shouldn't just accept someone's explanation or vague gesture at an explanation, but really break it down to a point that you can build it back up in your own logic/words/understanding.

 

[bobdavis]

I'm surprised that none of the options was "When your understanding matches experiment"

 

[Wrichik Basu]

The options are not enough, unfortunately.

As a student whose interests lie in beams, when I read a paper, I know I have understood it when I read another paper along the same lines, and I find that with my knowledge of the earlier paper, I can understand the other paper. Often, I read a paper twice or thrice, and then make notes from it, which summarizes the main points in the paper, and then I know which parts I have understood, and which I haven't.

In a recent virtual visit to the ATLAS, a question was asked which was not in the realm of the hosts. It was regarding beam operation in the LHC, and I had already read a paper on that specific topic, so I answered it. Well, definitely not in very layman terms, so not akin to explaining it to a child. But afterwards, I had a good feeling that I was able to answer somebody's question.

 

[ipsky]

"When your understanding matches experiment"

What experiment(s) have helped you know what you have understood?

The options are not enough, unfortunately.

What additional options would you include, and why?

 

[Wrichik Basu]

What additional options would you include

"None of the above."

and why?

See my post #7. None of the given options apply to me.

 

[ipsky]

See my post #7. None of the given options apply to me.

Yes, I understand none of the options apply to you. I thus asked for the option(s) that 'do' apply to you. I'm hesitant to consider comprehension of a few papers, and answering a few questions on them, as a measure of how well one understands a topic in physics. If you believe it has helped you, then I would like to know how accurately others can evaluate the same for themselves.

 

[Fred Wright]

IMO one never truly understands a topic in physics, one merely gets used to it (kind of like marriage).