Somehow my flag for too broad got declines on this question: What is time dilation really? . Just the fact that the answer spans over 3 actually answers proofs by definition that this question doesn't below on a StackExchange site. There is a limit on answer length with a reason. Wanted to flag W...
Hey guys, I have a basic question, why is it that the notion of "Force" in QM usually ignored, even though we talk abt terms like <-dV/dx> and d<p>/dt which are similar to "force", but the books dont usually use the term force.. why is that?
@vzn since the election I haven't really gone back in, so I dunno. I guess it's mostly quiet, I haven't seen any flag-fests or meta posts coming out of it.
@TheGhostOfPerdition Because the significance of force is classically that you think about it as acting on a point of an object. Quantum objects don't have definite positions, it doesn't really make sense to speak of a force acting on them
Re David Mulder's warm congratulations on my canonical questions, if his question got heavily downvoted and my answer got heavily upvoted I wouldn't be crying myself to sleep.
I suspect there aren't enough of us in the chat room to form a representative sample of the site membership, but I would be interested to know how people feel about my recent trilogy of canonical Q/As.
@JohnRennie Yes and kind of, but given that we want canonical questions and answers I think the legalistic approach to "too broad" is not in the interest of the community.
@TheGhostOfPerdition Because quantum mechanics is a Hamiltonian theory. You can do mechanics in the Hamiltonian form too, and you don't talk about force then either.
Aside. I'm teaching Classical Mechanics this semester and while student latch on the Lagrangian Mechanics as useful it is really hard to motivate them to take Hamiltonian mechanics as seriously.
Thinking about it now, I suppose the canonical questions might be useful because we're always trying to increase the amount of interesting/high-level questions at the expense of uninteresting low-level questions. And the more prominent the canonical questions are, the fewer people will be asking them.
More-over, where there are many versions of a question asked by beginner there are usually many bad answers as well. And because they are spead all over the bad answers don't get voted down enough.
What I mean to say is, the concern some people might have had, that having featured questions on basic topics would bring in droves of amateurs who would then proceed to ask lots of other bad questions, maybe isn't such a big deal
How does excitation takes place like we know about state of energy of electron and it's excitation to higher energy?? How does atom excite why is there atoms energy levels??
@dmckee I tend to think of Hamiltonian mechanics as the more elegant of the two. Have you done Noether's theorem for the Lagrangian? Then you should be able to convince them that being able to directly generate the symmetry from the Noether charge is a powerful tool - in Lagrangian mechanics you can't really get a symmetry from a conservation law, in the Hamiltonian formalism it's obvious
Hey guys I hope u could help me out, I want to be a physicist, I have a job now which I cannot afford to leave to pursue higher studies (Financial constraints), So I'm only doing Self study now... I still manage to study 30 hrs per week... Any suggestions or tips on how I can do better?
@dmckee Might they then be convinced that first-order Hamilton equations of motion are "simpler" than the second-order equations the Lagrangian formalism generates?
@TheGhostOfPerdition what qualifications do you have? In the UK I'd ask about GCSEs (age 16) and A levels (age 18) but I don't know what the corresponding Indian qualifications are
@sharafzaman Engineering. Math. Process optimization. Software development. Image processing. Electronics. Many things related to physics, but not really physics.
@TheGhostOfPerdition pretty much just what I said, that it's not as interesting of a job as it looks from the outside. Lots of stress, low pay, and very little flexibility. It has perks, of course, but also significant disadvantages.
@ACuriousMind But you usually have a master degree, right. Many (most?) US programs go straight from a BS to a Ph.D, so part of the difference is in doing the master's equivalent course work.
@TheGhostOfPerdition I don't think people without PhDs get jobs as lecturers, and most lecturers are actually researchers who are lecturing on the side.
In the UK it's very hard to get an academic post as a physicist, and you're competing with people much younger than you and with a physics degree and PhD.
@HariPrasad Then keep plugging away at it. A lot of stuff that "physicists" do, also needs doing in other jobs. It just gets lumped under different titles. and with different auxillary work.
@ACuriousMind Yes I do have plans of doing a Masters and a PHD, But the thing is its hard to quit my job, coz in my country Its very hard to get decent physics profession
There are lots of jobs that involve applied physics. I went to work for Unilever, a company that makes consumer goods then worked for 12 years studying colloid science.
Anyway I want to sneak something in before the chat session ends: on generalizing the homework policy, there seems to be a clear favorite answer suggesting that some kinds of calculation requests should be on topic. We should try to figure out how to focus that. Next chat session I hope to have something more prepared to discuss on this topic, but until then, let's think about it.
@TheGhostOfPerdition I'm reluctant to offer firm advice because I know so little about UK jobs let along Indian jobs, but I suspect you would find doing a PhD pretty hard.
@vzn If you work as an experimental physicist in industry then by age 40 you will either be a middle manager, a glorified lab technician or unemployed.
@JohnRennie In truth most of the jobs are mostly developmental, and many of your colleagues are going to be engineers. But development departments also do some resaerch and a physicists skills are useful for that.
@TheGhostOfPerdition if cost is a big concern, that's not a bad way to start. You can go through community college for a couple years, then transfer to a 4-year university to get a bachelor's degree, and then apply to grad schools. Once you get into grad school, you no longer have to worry about finances (well, relatively) because you get paid a stipend.
@TheGhostOfPerdition Don't be deceived by the golden badge. I know how to have fun with metrics, and that's about all. I bow at the feet of the real relativists hereabouts :-)
Universities continuously spit out ambitious young scientists eager to get to the bench. Someone with the skills to organise them into a productive team is enormously valuable to a company.
@dmckee It's lucrative too! The reason I can afford to spend so much time on the Physics SE is because Unilever paid me so well while I was working for them :-)
@JohnRennie I don't expect to make as much at the end of my university career as Dad did when he was forty. And he was only a part-time manager (but they did give him nearly half of their new hires to train).
How does excitation takes place like we know about state of energy of electron and it's excitation to higher energy?? How does atom excite why is there atoms energy levels??
