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3:00 AM
And copious benefits.
All the things I don't have at my little state school.
 
I expected something around 150k/year so fine
There is condensed matter guy at my uni leaving ship
 
@G.Bergeron In places like Boston and NYC those are the numbers that bounce around.
 
@dmckee my little state school gave me the things I needed to send me off somewhere nice, so I can't complain too much
 
for a place in the US
 
A lot of Harvard and MIT profs can afford to live in Harvard.
Which is just crazy talk.
 
3:02 AM
@dmckee But salaries are about the same here...
Maybe a bit less (but in canadian dollar)
 
so far the best advantage of my current university is the physics department has an alcohol budget instead of ban
 
@dmckee If you can do research, then it's fine
 
Last I looks the Canadian dollar was a lot closer to parity with the US dollar than it was for most of my life. At one point during the crash it was worth more than a greenback.
@G.Bergeron I am encouraged to do all the research I can with no money, no space, no equipment, no release time and no assistance.
 
@dmckee OK, but isn't somethin like 120k/year what you would expect uni prof to earn after some time in their career?
 
Actually, the IT people gave me a four year old computer and a monitor, so I've got some equipment...
 
3:04 AM
@dmckee ouch, this one hurts
 
@dmckee Grants from governement? Professors gets nothing from the university here
Actually they need to pay for lab space and all
 
they gave all of us decked out new computers for our offices
decked out enough that it's actually useful to run my long computations on (!)
 
Everything comes from grant which you get from 2 or 3 governement agencies
 
@G.Bergeron Hard to get a substantial grant when you have to teach full time. The adgencies are wary of your ability to get things done in a timely manner.
 
@dmckee What is full time?
 
3:06 AM
@G.Bergeron a hell of a buzz word (with somehow concrete consequences)
 
The uni does offer small amounts of money to students with pjrojects, so I spend some time thinking up things the students can do for ~US$400 or so.
 
And I know it's hard, research funding is a bit in crisis
 
@G.Bergeron 12 semester hours per term, Fall and Spring. In principle I have summers free.
 
I mean to get mine for the master, I had to pretty much have perfect grades as an undergrad. This is ridiculous
 
I feel bad for the adjunct faculty here @dmckee
it's in the graduate student union contract that we are paid the same as the adjunct faculty per class time
 
3:07 AM
You can feel be for the adjuncts everywhere. Even when the department head is looking out for the they get screwed by the system.
 
@vzn It's an interest free loan :)
 
they aren't even paid better than us
 
@dmckee Which is really nothing research wise. I'm so happy to be in theory. Once my livelihood is paid for, nothing much more is needed
@dmckee That's like two classes, right. But then what, the private university professors do not teach at all?
Me too, some friends want to go party
I think I'll go
 
@G.Bergeron as far as I can tell, for the majority of the department, yeah
 
Degrees of freedom come from the number of coordinate directions that a system can move in, right?
 
3:09 AM
@GPhys WHAT?
 
and the exceptions seem to be mostly their choice
They teach graduate classes
 
@G.Bergeron Three. Four in departments with the typical class is 3 units (but ours are usually 4).
 
if that counts
 
So if a particle can move in the $+x$ direction, then it has 1 D.O.F and if it can also retrace its steps, i.e. move in the $-x$ direction, then it has 2 D.O.F. right?
 
@whatwhatwhat Number of real number indexed parameters to specify a state in time
 
3:11 AM
At better state schools profs teach three to five courses a year. A prestige schools they teach two or three. Less if they have an endowed chair.
 
no that it is still one
 
@G.Bergeron Oh so then even if my particle can move in both the positive and negative x-directions, it's still only 1 D.O.F?
 
@whatwhatwhat Yep.
 
Ah I see.
 
@dmckee I think professors need only to teach 2 courses. But then they need to get grants.
Or byebye it is until tenure
 
3:12 AM
@G.Bergeron Yeah. Bringing in money is part of what goes with those reduced teaching loads.
 
@G.Bergeron well, the professors probably need to teach enough courses to get the poor little kids like me to the end of their degree
maybe not every university has so many extra bodies to do this
:P
 
@dmckee And there are only two funding agencies here, federal and provincial
Unless you're curing cancer, building quantum computers or doing microfabrication if you see what I mean
 
how do you guys learn what you learn about physics? im in high school and i know more about the easter bunny then some of the questions asked on here
 
@GPhys Yeah, well one per semester is quite enough
@mochacat School < Internet < Books
4
<<<<<<< Papers
 
@G.Bergeron @dmckee I think the NIH adjustment to the budget here is larger than the NSF entire budget
 
3:15 AM
papers :(
 
@GPhys Yeah these kind of things are probably reflected worldwide
 
any good places to start? i live close to a nice library and i'm going to have alot of time over break
 
I heard they managed to fund a swanky gravity wave doohicky though ;)
 
Like one F35 being the budget of the whole federal funding agency in natural sciences
 
22 years later they even found one
 
3:16 AM
@mochacat Books then
Don't start with papers, it's useless but that is still where I learnt the most over time
And nowadays you have like infinite resources about basic topics on the web so watch lectures, go on wiki trips, what suits you
 
@mochacat You have to take enough course work to set the stage, but the real learning comes from (a) applying what you have been taught to harder problems; (b) reading enough to see what is being done with these things on the cutting edge; (c) teaching and supervising student researchers where more book learning happens than anywhere else; but most of all (d) research.
You build up to it, and it take time.
Even the people who look smart now started ignorant and struggled along the way.
 
@dmckee I agree coursework is structures and gives you the constant push in the back because you have to hand-in stuff.
 
do you think i should wait and see what happens in school first before I take things into my own hands? @G
 
I am passionate, but sometimes you would just go over material lightly unless being thrown in.
@mochacat If you have the motivation do it!
Whatever you learn and however inefficient you are is not a problem. Think that most people do not learn stuff on the side!
Everything I know about electronics and programming was learnt on the side
Electronics mostly in high school and then programming later on
 
that's where i hope to get, i just have to build some foundation and then scrape together some motivation. i envy you guys who learn so many things on your own
i love physics/electronics/web-dev and i'm making good time in everything except for physics. i keep shunting it aside for something else
 
3:25 AM
@mochacat It might help to have a project when learning on your own. It gets you motivation but also restriction from not just spreading your time on covering material only on the surface.
Physics is harder to learn on you own in my opinion
 
yeah physics is brutal. there's always some foundation that i'm missing but i'm getting there
 
School < Internet < Books LOL who starred that?
 
@G.Bergeron yo
 
@mochacat A degree helps in that it is paced
Haha
Alright it's getting late and I want to meet with friends... See you people
 
arite cya @G.Bergeron :) thanks for the talk
 
3:28 AM
@G.Bergeron bye friend!!
 
vzn
@G.Bergeron (rats keyboard died) what kind of (comp) experiments?
 
what?
 
vzn
@G.Bergeron oops mixed up. anyway plz seriously think over the spkr session & get back to me, there seems to be an audience hungry for experts around here :)
 
all right i'm gonna be off now too. you guys have fun talking about your red-shifts and ricci tensors. hope to be more active on stack exchange in the future :) have a good one guys
 
@mochacat bye new friend!
 
3:30 AM
@vzn Ok will let you know as soon as possible
 
vzn
@GPhys what kind of (comp) experiments?
 
bye :) @whatwhatwhat
 
vzn
@G.Bergeron thx much think its a real highlight around here when it happens... "once in a blue moon"... youre in great company if you look at the list :)
 
3:47 AM
Hi guys. And girls. :)
What are you all talking about?
 
@DanielSank Whats up
 
@Skyler grocery shopping
 
nice, btw, you like nutella?
 
@Skyler uhhhh, sure. Who doesn't?
 
@DanielSank met a few actually
 
3:52 AM
Exactly, who doesn't.
 
probably a statistically disproportionate amount of people
 
 
2 hours later…
5:25 AM
Anyone here?
@JohnRennie you there?
 
Morning
 
5:41 AM
@vzn My homework
Time for anonymous course evaluations!
 
user228700
@JohnRennie: Morning, morning! :-) Still in Dubai, apparently :-/
 
You have mail ...
 
[Division by zero] Actually... one can call this one an example of an associative unit zero divisor division by zero algebra (i.e. an associative algebra that allows both an inverse of zero and a zero divisor with nilpotent inverse), as the element 3 is actually the unique zero element (being a (one sided) absorber and additive identity)

Why on earth this is a zero element instead of 0 requires further analysis
 
user228700
@JohnRennie Awesome! I'll wait :-D
 
user228700
@JohnRennie: I checked. They don't work on Sundays and on every second Saturday. Isn't today the 2nd Saturday of this month? Great :-/
 
5:50 AM
That's a pain. Just wait and see what happens I guess.
 
user228700
Yeah. At least it's on its way :-)
 
oh right
constructive criticism
 
user228700
@JohnRennie: I figured out s'thing I know me 3 months ago wouldn't have been able to!
 
Congratulations :-)
All the way through school and university I'd look back at the previous years work and think that looks easy :-)
 
user228700
I derived the electric field intensity at a point on the axis $x$ distance away from the center of a uniformly charged disc.
 
5:55 AM
disc or ring?
 
user228700
Disc!
 
Area integrals!
 
maybe I shouldn't attempt to write constructive criticism right now
 
user228700
Well, not really :-P I considered the element to be small concentric rings.
 
user228700
It was awesome when I figured it out. I had no faith in the fact that my answer would match but I finished and yaay, what dya know, it matches!
 
user246160
5:58 AM
@Kaumudi Isn't that given in all physics textbooks ? :P
 
Ah OK. So it is a 2D integral, but the first integral just gives you the field for a ring so the next step is just adding up the rings. Still, it's not a trivial problem. I didn't do calculations like that until 1st year at university.
 
user228700
@TheStackExchange Nope. I did it from scratch. Well, I knew the expression for a ring but yeah, nothing else.
 
user246160
@Kaumudi You could use gauss law....
 
user246160
It would be easier
 
user246160
But taking rings is the standard way
 
user246160
5:59 AM
:)
 
user228700
@JohnRennie Yeah. I felt super happy! :-D
 
user246160
@Kaumudi It is given in my books fortunately with proof
 
user228700
@TheStackExchange My textbook asked me to solve this before introducing Gauss's law.
 
user246160
I see :)
 
user246160
Congrats !
 
6:00 AM
@Kaumudi You'll find there's a kind of critical mass type effect. At first integrals like that seem very hard but then one day you realise they have become routine.
 
user228700
:-P Thanks. It's not a big deal but I felt awesome.
 
user228700
@JohnRennie I'll tell u when I get there :-)
 
That happens over and over. When I first started learning GR it seemed incomprehensible, but now many parts of it feel just, well, easy :-)
 
user228700
God, u said many parts of GR are almost intuitive now :-o That's s'thing else.
 
At the moment quantum field theory seems incomprehensible but I'm confident that if I keep at it one day it will seem easy as well.
3
 
user246160
6:03 AM
@JohnRennie How many years did you take to learn GR ? :) I haven't started yet :P
 
@JohnRennie I cannot even begin to comprehend that QFT will begin to be shoved on me in a year or so
 
@TheStackExchange I first got intrested over a decade ago! But I do it just as a hobby for fun. If you do it at college it's a much more intense course.
 
@TheStackExchange I'm interested in the answer to this question as well
Could someone help me with my question? Have not understood it yet. Link
 
user246160
@JohnRennie No idea if in engineering they will teach GR. I hope to learn it for fun next year :)
 
@JohnRennie From what I understand, after we do the regular Quantum run through, our university has QFT 1-3 where QFT 3 is aimed at the theorists, and there's a separate class on (more basic (?)) particle physics
 
6:06 AM
@TheStackExchange GR isn't that hard. It's basically differential geometry and if you're comfortable with calculus then you can pick it up pretty quickly. I doubt it will be taught in an engineering degree!
 
user228700
@JohnRennie U didn't ask to see, but u should see how ur student (:-P) has been improving:
 
user228700
 
user228700
 
that reminds me
I'm so glad I only have to grade typed lab reports
 
user228700
 
6:07 AM
Your notebooks are so much tidier than mine :-)
I do the calculations on large sheets of paper and when I've finished it looks like a drunken spider walked through a puddle of ink :-)
 
user228700
It's safe to say that I'm a bit of a perfectionist so that's no surprise :-P
 
I found a yellow notebook on Amazon that my pen put down well on, so I bought 12 of them
 
user228700
@JohnRennie x'D That's such a wonderful description.
 
@JohnRennie I use loose leaf printer paper and when I'm done it looks like I've set out to intentionally waste trees
 
The trouble is that I tell my niece off for not writing things down carefully when doing maths problems, and she just looks at me as if to say look who's talking :-)
 
user228700
6:11 AM
:-P I see.
 
@GPhys I know that feeling :-)
 
I found some of my math papers once from when I was quite young (elementary-middleschool-early high school)
I did all my calculations in the margins of the paper arbitrarily
they were completely filled with quick calculations (like adding,multiplying 2+ digit numbers, etc) in arbitrary orientation while the main body neatly written
 
NB mistake, that configuration have no zero divisors because 3 but not 0 is a zero element. (It is also not associative for one entry)
 
user246160
@Kaumudi So, you had that pizza ?
 
6:32 AM
Hi guys.
 
user246160
@SwapnilDas hi
 
@TheStackExchange Sup?
 
user246160
Allylides Methanides and Acetylides :-D
 
user246160
Ionic carbides
 
Oh God.
 
user246160
6:34 AM
@SwapnilDas you?
 
user246160
:)
 
@TheStackExchange NLM
 
user246160
@SwapnilDas Oh i see...that is one hell of a chapter..problems never seem to end :P
 
Exactly!
 
user246160
@SwapnilDas Did you join the jee chatroom ?
 
user246160
6:37 AM
Oh yeah,,you did...sorry :P
 
Yes :)
 
user228700
@TheStackExchange What kind of person dyou take me for? I eat the food the first chance I get. And that too, pizza! Shiv shiv.
 
"Shiv Shiv" ><
 
user246160
@Kaumudi Hehe. I wanted to know whether the pizza was delivered to your home, safe and sound :-D
 
user246160
Once I ordered a pizza and my neighbor bought it instead. He has the same surname :P
 
user246160
6:48 AM
Nowadays I wait outside the house for the delivery guy to arrive !
 
user228700
x'D That must've sucked.
 
user246160
@Kaumudi I was planning to kill my neighbor that night by stabbing him with a knife ;D
 
user228700
My parents went and brought it home from the pizza place. It's not very far from my home and my cycle didn't have any air I'm the tyres.
 
user228700
@TheStackExchange Oof. That's a little rough :-P
 
Cycle. RIP.
 
user246160
6:51 AM
@Kaumudi I don't compromise on my food. Like ever :D BTW you got from dominos or pizza hut ?
 
@Kaumudi did you really eat a chocolate pizza?
 
user228700
 
user246160
@Kaumudi You should buy an air pump for home :P
 
user228700
@JohnRennie No, not yet :-D It doesn't sound very good, does it? :-/
 
user228700
@SwapnilDas Nah, it's fine <3
 
user228700
6:53 AM
@TheStackExchange Dominoes.
 
@Kaumudi it sounds pretty terrible :-)
 
I can't drive a cycle now perhaps.
 
user228700
@JohnRennie :-P Well, I'll let u know next month, possibly...
 
user228700
@SwapnilDas Why not? :-(
 
user246160
Some of my friends said that the choco pizza tastes well, if taken in small doses :P
 
6:54 AM
@Kaumudi You can get them inthe UK though I've resisted the temptation so far.
 
@Kaumudi not driven from the last 5 years perhaps.
 
> topped with a rich, decadent chocolate sauce, milk chocolate chips, white chocolate chips and finished off with a delightful brownie crumble.
 
So I've lost practice, and time also.
 
Hmmm ...
 
user228700
Hey, that actually doesn't sound so bad!
 
6:55 AM
@Kaumudi Nooooooooooooooooooooooooo :-)
Actually I suppose it's not that different to chocolate biscuits, and I like chocolate biscuits.
Maybe I'll buy one today and see what it's like.
 
@JohnRennie Even I do.
 
user228700
Gosh, that would still be SOOO much better than this:
 
user228700
 
user228700
@JohnRennie That's the spirit! :-P Tell us how it is if u do :-)
 
user228700
6:59 AM
What are u, their sales rep? I gotta tell u, u're doing a pretty bad job :-P
 
If I'm honest I'm still pretty sceptical about this
 
user228700
This argument is very very bad but still: YOLO!! :-P
 
user246160
@JohnRennie What are the pizza brands prevalent in the UK ? :-D Do you guys have dominos or pizza hut ?
 
user228700
@JohnRennie: C'mon, it's not only chocolate!
 
user246160
@Kaumudi As a matter of fact, I just found a bournville in my refrigerator, hidden few days back by my mom (under newspapers :P)....yahooooo....i stole it now!
 
7:04 AM
@TheStackExchange yes, both Domino's and Pizza Hut trade in the UK though I don't often buy pizza from them. I tend to buy the supermarket pizzas and add extra toppings of my own choice.
Pro tip: buy a basic cheese and tomato pizza, cook it nice and crispy then put butter chicken on top. Mmmmmmm :-)
2
I'm hungry now, and it's only 7 a.m.
 
user246160
@JohnRennie Sounds too good :)...but unfortunately I am on a diet....I need to lose 5 kgs before I can eat fast food again :P
 
user246160
LOL XD
 
user246160
12 noon here
 
@JohnRennie This is a scheme my wife and I use to great effect. Adding mozzarella balls and salami improves most pizzas. And sometimes sliced garden tomatos.
 
@dmckee Oooooooooooooooooooooh :-)
 
user228700
7:09 AM
@TheStackExchange OMG!!! Now I'm jealous of u :'-(
 
@JohnRennie U seem to be happy today, don't u?
 
@dmckee Can you get Polish sausage in your bit of the US? If so that works really well on pizza.
 
@JohnRennie Well. We can easily get a kind of mass produced thing that goes by that name. You have to work a little harder to get a good one. But I've never tried in on pizza.
 
user228700
@JohnRennie: Last question. Have u seen "Harvey", the movie?
 
@SwapnilDas I wrote a really good answer yesterday, I have a new laptop in the post to me and I've got a great meal planned for lunch. Right now life couldn't be better :-)
 
user228700
7:11 AM
@JohnRennie Ey! Another laptop? :-)
 
user246160
@Kaumudi Revenge is best when served cold >;) Anyway I am still thinking how much chocolate to eat. 73 kgs. Hmm. If I eat one chocolate it will add 300 calories. Then I need to run 5 kms to lose it again. Dhur! I have such a bad metabolism :P
 
12 hours ago, by John Rennie
@BernardMeurer: I need help. Clinical help that is. I just bought this for no better reason than I thought it looked fun :-) Dell Inspiron 17R-5720
 
user228700
@TheStackExchange x'D
 
It's an addiction, but unlike hard drugs it's unlikely to kill me.
 
user228700
But it might leave u broke :-P
 
user228700
7:13 AM
Last question!! Have u seen "Harvey", the film?
 
user246160
@Kaumudi He has too much money :P
 
user246160
Richie Rennie :-D
 
user246160
Harvey is a 1950 comedy-drama film based on Mary Chase's play of the same name, directed by Henry Koster, and starring James Stewart and Josephine Hull. The story is about a man whose best friend is a pooka named Harvey — in the form of a six-foot, three-and-a-half-inch tall invisible rabbit. == Plot == Elwood P. Dowd (Stewart) is a middle-aged, amiable though somewhat eccentric man whose best friend is an invisible 6' 3½" tall rabbit named Harvey. As described by Dowd, Harvey is a pooka, a benign but mischievous creature from Celtic mythology who is especially fond of social outcasts (like Elwood...
 
user246160
1950? Seriously ?
 
user228700
Yeah. I hear it's excellent :-) I need to watch it in June.
 
user246160
7:17 AM
I am going to watch Raees and Dangal :-D Yeah!
 
@Kaumudi no, I'm not a great film fan.
 
user228700
Raees?
 
user246160
@Kaumudi yep :)....seems fun
 
user246160
Raees (English: Wealthy) is an upcoming 2017 Indian action crime thriller film directed by Rahul Dholakia and produced by Gauri Khan, Ritesh Sidhwani and Farhan Akhtar under their banners Red Chillies Entertainment and Excel Entertainment. It stars Shah Rukh Khan, Mahira Khan and Nawazuddin Siddiqui. Raees is said to be based on criminal Abdul Latif's life, though the filmmakers deny this. The film is scheduled to be released on 25 January 2017. Raees is based on a real life character - underworld don Abdul Latif. "Latif played an important role in the decline of congress and growth of BJP in Gujarat...
 
user228700
Okay :-) I have too many things to do on my "June to-do list". Can't possibly list everything here. Anyhoo. Lunch time!
 
user246160
7:18 AM
I am going to watch more because of Nawaz than srk though :P
 
user246160
Ok bye
 
user246160
:)
 
@TheStackExchange People want success everywhere in life. What's the only place they want failure?
Any idea?
 
user246160
@SwapnilDas There are several places....
 
user246160
Like failure to die :P
 
7:22 AM
No 😛
 
user246160
@SwapnilDas Why, no?
 
Answer is a flower shop.
Don't you want a 'haar'?
 
user246160
Very low grade joke. -1 votes. :P
 
Lol, IAS interview question.
I had similar remarks, votes being -infinity
 
user246160
@SwapnilDas I would really leave the interview if the interviewers are so stupid !
 
7:24 AM
True.
 
Good afternoon
 
Good Afternoon
 
Can somebody help me in ques 17
In this what does P(AB) signifies
 
Image still loading :/
 
@koolman I think $P(AB)$ just means the probability of both $A$ then $B$ occurring.
 
7:35 AM
Then @JohnRennie P(AB) should be equal to P(A)P(B)
 
user246160
It is P(A intersection B)
 
@koolman Yes, and it is isn't it?
 
user246160
@koolman That is not true. It happens only when the events are independent.
 
@JohnRennie but there is P(B|A)
@TheStackExchange so what does it signifies
 
user246160
7:38 AM
P(AB) here means probability of both A and B occurring....intersection of the two events
 
@koolman P(B|A) means the probability of B if A has already occurred
The point is that after A there is one less ball in the bag so the probability of getting a blue ball changes after one white ball is removed.
 
@TheStackExchange but intersection of both A and B is zero
@JohnRennie then we cannot say P(AB) should be equal to P(A)P(B)
 
user246160
@koolman How on earth is it 0 ?
 
user246160
A and B are two consecutive events as defined in the solution
 
user246160
A is event of drawing first ball white
 
user246160
7:42 AM
B is event of drawing second ball blue
 
user246160
P(AB) is probability of both A and B occuring and $P(AB) \neq P(A) P(B)$ because A and B are dependent events
 
@koolman it's just a matter of notation. If you take P(B) to mean the probability of drawing a blue ball before any balls are removed then you're correct P(AB) is not P(A)P(B).
Because obviously the probability of drawing a blue ball changes when one ball has been removed.
 
@TheStackExchange as intersection of A and B is null , how white and blue ball are related
@JohnRennie ohk
 
user246160
@koolman Why is intersection of A and B null ? Can't the events occur one after another...B after A
 
@TheStackExchange yes
Ohk I got it
 
user246160
7:46 AM
@koolman so ? how is it null ?
 
user246160
good :)
 
Thanks @JohnRennie @TheStackExchange
 
8:24 AM
Hey people
in figure (a)
why will the red force be T/2 and not 2T?
The total force on the pulley by the 2 blue forces is 2T, each T from one side of the string.
 
sometimes PDEs really confuse me
 
partial differential equations
 
Is this related?
 
I'm working on a few diffusion problems and I have no idea why they are easier than the same electrostatics problem
nope, just venting
 
8:33 AM
oh, okay
 
lets take a peek at yours for a sec
 
If I have 2 masses attached to each other by a spring which rotate about their center of mass and also slide down a frictionless plane, what are the relative motions of the 2 masses? My friend says gravitational, translational, rotating, oscillatory. I don't think that's right, I think there is only rotational and oscillatory. Which of us is right?
 
@OsheenSachdev i thinkn youre red arrow is drawn wrong
the 5kg mass is accelerating down
 
The keyword here being relative. I see how you get translational motion going down the plane, but that is not what is in focus here. I take relative motion to mean motion occurring between the 2 masses, ignoring the plane.
 
@Skyler Thats tension in the string
 
8:36 AM
@whatwhatwhat im seeing your starred comment and totally can relate sometimes
 
@Skyler the one about classes in heaven?
 
the annoyed with undergrad physics
checking context for the heaven one
thats some cheap tuition
 
My arrows are forces
@JohnRennie any inputs
 
btw im pretty sure T on the right is different than the other two
 
@OsheenSachdev the red force is 2T i.e. 8g Newtons
 
8:41 AM
actually scratch that
 
But the answer given is different
1 sec
 
@Skyler yea I don't find undergrad physics fun at all, and this is coming from a guy who, when he was young, would have fun by literally just imagining things. Like just sitting somewhere and thinking. I feel drained of enthusiasm and creativity :(
 
I REALLY like statistical mechanics, and quantum is interesting
classical kind of kicked my butt but I got it
 
Btw, my question above is just a conceptual one. If someone has 5 seconds to process it, that would be incredibly helpful :)
 
@JohnRennie Thank you, got clarified :)
 
8:43 AM
so far EM has just been a TOTAL drag
 
@Skyler EM was kinda interesting for me. QM kicked my ass - I just took a final on Wednesday where, for one question, I had the correct answer, erased it because it didn't make sense, then wrote a wrong answer in its place. When I asked my classmates later they said "Dude, it's QM, it's not supposed to make sense."
facepalm.jpg
 
@Skyler Electrodynamics always felt to me like an excuse for examiners to set stupidly complicated questions where we had to do boring calculations. And that's a shame because Maxwell's equations are actually really cool.
 
@JohnRennie do you know which of us is right?
 
@whatwhatwhat I guess it depends on how you look at the situation. I would interpret relative motion as being motion measured in the centre of momentum frame of the masses. In that case obviously there's no translational motion because in the COM frame the net translation is zero.
And likewise, in the COM frame the masses are moving freely i.e. not subject to any external force, so there is no gravitational force either.
So in effect you just have two masses on sperings and rotating around their mutual centre of mass.
 
need to reword
So in the COM frame, if we ignore gravity, doesn't this cause a problem with the oscillatory motion? Imagine the system oscillating and rotating as it goes down the plane. Doesn't gravity give it a weird rotational swing where as one mass swings down towards the bottom of the plane, it pulls on the spring harder. Likewise, as the other mass goes up the plane, the spring length shrinks down.
 
8:57 AM
@whatwhatwhat the plane is frictionless, so both masses have the same acceleration down the plane of $g\sin\theta$ where $\theta$ is the angle to the horizontal. Since both masses experience identical gravitational accelerations there is no effect in the COM frame.
I have to go work for an hour or so. See everyone later ...
 
9:50 AM
Is anyone able to help with shm
 
user246160
@John Ask.
 
For example with a pendulum, the sum of kinetic and potential energy at a point is constant, but why do we assume w(angular frequency) is constant
 
Hang on, is dtheta/dt = 2pif
 

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