L13.4 Charged particles in EM fields: potentials and gauge invariance

MIT 8.06 Quantum Physics III, Spring 2018
Instructor: Barton Zwiebach
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L13.4 Charged particles in EM fields: potentials and gauge invariance
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[@victoriarisko]

No one makes Challenging Physics more fun and entertaining!!!

[@SolSystemDiplomat]

I find one notebook for maths and one notebook for chapter notes plus completing the chapter before class… but when I get stuck on a maths problem… and this is the important part… when I get stuck on a maths problem, I write down exactly what my question is and move on to the next maths problem. All those questions I could not answer get answered during my prof’s office hours. Always schedule a time. I dropped my study time a night from 6 hours to 3. There is no class that cannot be conquered with proper study habits.

[@AkamiChannel]

I came here bc I wanted to understand c. Now I realized I had better go through a whole EM course before trying to understand this video.

[@arlesterchristian8805]

Great lecture. One question - for the professor or anybody else that might know on this thread - what is an example of the lamda function that needs to be found that makes the equations gauge invariant/symmetrical? I have seen a lot of videos like this that make reference to being able to 'add the gradient of some function lamda' to the equations for the fields but I have not found a worked example of what that might look like. A link to such an example or explanation would be fine. Thanks in advance for response.

[@jimmyleo4718]

If my lecturer can do lecture like this, I will learn better in physics.

[@TarunKumar-er8qq]

Why he wrote the third equation of maxwell with 1/c2 .

[@danielfajardo963]

Because he's using the Gaussian system of units

[@Summering-o8s]

Love u!!!

[@johanastborg8066]

thanks!

[@4pharaoh]

When trying to describe anything in nature, in any pedagogical method other than using math on a chalk board he reverts to using his hands to mime what he is trying to convey. Surely describing a Wilson Loop shouldn't look like a game of Charades. I know MIT can spring for something a little more substantial than chalk alone for 100K/year•student. My personal opinion: This limited approach to teaching is inexcusable 19 years into the 21st century. Also, these Videos are advertisements for MIT. Your future students critique them, your competition will one day cite them. Don't get me wrong... I am watching this for free, and I do sincerely thank you, I do appreciate it. So please take it as intended: As Constructive Criticism. The harshness of my comments are strategic, meant to sting not to harm, to encourage reflection not reflex. to stimulate reform not rebuttal.

[@allenho2778]

This is not constructive criticism. I was drawn to physics by nothing more than a professor using chalk and blackboard. I continued my studies until I received my Ph.D. many years later. I also disagree that these videos serve as advertisements for MIT. In science, to be cited by competitions is a great honor.

[@Scarhandz]

This was a beautiful and imo, correct critique.

[@Scarhandz]

@@allenho2778 I think what he means is, technology has far exceeded the usual simple teaching methods of chalk on wall, human reads, like a cave man. Despite producing amazing talent....might be time for a change. I say... "Here, Here. 👏👏".

[@curiosityzero2151]

@@allenho2778 agreed.

[@kgfcccvvhbbbc7565]

@@curiosityzero2151 I don't interest my professor use chalk or anything. I understand quantum lecture him. My professor is hero in my minds 😊😊😊