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05:04
never heard of it
user116211
WTF!
user116211
Griffiths
user116211
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ hahaha
user116211
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ: BTW, why is your name in a different font?
05:07
I made it that way :)
user116211
O.O
Even mods have blue names.
@user36790 um, ok
user116211
@0celo7 I really had problem in understanding this book
user116211
Don't hate it but don't like it either
05:11
holy shit this normal vector will kill me
What's your favourite physics textbook @user36790?
user116211
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ which topic?
user116211
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ O.O
user116211
05:13
There is actually no good book on overall physics
Ok, Newtonian mechanics.
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ Arnold.
user116211
Fat books that come under two or three authors like Resnick, Halliday, Walker and many others are Engineering books; not physics. You can't learn many things from them unless you only want to cram fomulas
user116211
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ French's Newtonian Mechanics
I would like to one day read Rudolph and Schmidt's classical mechanics book.
user116211
05:15
@0celo7 Did you ever follow thermodynamics?
@user36790 I read Fermi's book on it.
user116211
@0celo7 Oh! That small pink book.
@user36790 Yes.
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ Well, it's not what you asked for because it introduces Lagrangian and Hamiltonian mechanics only a third of the way through, but I've always been a fan of Marion and Thornton (now sadly out of print).
user116211
@dmckee Archive?
05:17
@dmckee Have you heard of Rudolph and Schmidt
@0celo7 No. What level is the math? We're looking for a new Junior level mechanics text.
@user36790 Sadly it is no longer in my possession.
@user36790 Probably, but I don't recommend things that aren't copyright kosher.
user116211
@dmckee:
05:19
@dmckee from the preface "We assume that the reader is familiar with elementary algebra and calculus, as well as with the basics of classical mechanics."
user116211
@dmckee But its price is equivalent to buy a Samsung Galaxy!
user116211
@0celo7 I bought in Aug, 2015; very cheap
@dmckee but of course -- the book is written by a pair of Germans
@user36790 Yikes. I might ask for a desk copy for my own edification, but I don't think I'll be able to recommend it for adoption.
user116211
@dmckee Yeh
05:21
@dmckee this introductory mechanics text invokes the word "topological space" on page 1
damn Germans
user116211
@0celo7 introductory doesn't mean it will start from ABC
user116211
It means you are well aware of the subject before reading that book
@dmckee seriously, have you looked at Arnold?
that's the German book
Arnold.
@0celo7 The students are not that mathematically prepared.
@0celo7 Make a list of stuff you want me to ask Bob Wald when I visit in 2 weeks
05:25
@FenderLesPaul nah
I keep meaning to get a copy for myself, but that's a different matter.
you won't do it
you've never once done anything you've said you will
not going to start hoping now
user116211
@0celo7 Heard of Vol 5 but WTF it is Vol 60!!
@user36790 the second edition
@dmckee Get it now.
@0celo7 wanna talk about the rope problem now?
user116211
05:27
@0celo7 second edition is called Vol 60!
It's a fun little book. Exercises are terrible.
@user36790 I suspect the volume number is in the "Graduate Texts in Mathematics" sequence.
@user36790 yes
@FenderLesPaul doing homework
@dmckee I thought this was clear.
05:28
I'll TeX up a solution for it now and you can look at it whenever
user116211
@dmckee: What about Statistical Mechanics?
user116211
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ roar
@FenderLesPaul throw in the black hole fall in thingie and we're golden
The maximum lifetime one?
05:29
yes
@dmckee I'm so used to my CAS, I can't solve $x=\mathrm{e}^{-t/t_0}$ for $t_0$ by hand.
@user36790 I don't know the field well enough to have a favorite. I used Goodman in college.
user116211
@0celo7 wow
user116211
05:31
@dmckee Oh! For me, Reif is the best
And a combination of the profs notes and L&L and and some other little text in grad school. Hated that.
user116211
@dmckee Have you read Reif?
@user36790 I read about a third of it and liked what I saw. But it assumes preparation that only about a half of our typical thermal physics students have.
user116211
@dmckee Really he explains things quite intuitively with many examples
If I knew the subject better I might try to write a statistical physics text from a classical perspective.
user116211
05:34
@dmckee O.O
@dmckee that German book looks interesting
I do have about five pages of revtext notes on the subject, but that is the barest introduction.
they tie the stability of orbits in phase space to the topology of the configuration manifold -- or something like that
they are apparently writing a book on yang-mills in the same style
@0celo7 Which is very cool, because it lets you think of classical and quantum theories in the same frame of mind. But it also makes my poor, tired, little experimental brain hurt.
@dmckee huh?
this has nothing to do with quantum mechanics
it's a nerd circlejerk over making $F=ma$ as abstract as possible
05:36
Perhaps I misunderstand. Marsden kicked my ass up one side and down the other.
Right now my copy is on load to a math prof. I think he likes it.
hmm, a book that contains the word "cech cohomology" is not good for a junior physics text in America
@user36790 reif is amazing
@user36790 are you trying to self-study stat mech?
user116211
@FenderLesPaul yep
If so I'd suggest a combination of books: Reif, Kardar (Vol 1), and Kubo's problem book in stat mech
user116211
@FenderLesPaul there are actually two books that is written by him.
05:39
Pathria is also a good replacement for Kardar but a lot of the problems in Pathria are also in Kubo
Why a "combination"?
Kubo's problem book is really useful if you're trying to really learn stat mech
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ in my experience just one of them wasn't enough
I had to use all three to get a decent handle on stat mech
user116211
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ you want permutation?
especially given how important the subject is
and how poorly it is taught
05:41
@user36790 two books written by whom?
user116211
@FenderLesPaul reif
Ah ok I didn't know
I meant the one on thermodynamics and statistical physics
user116211
@FenderLesPaul one is berkeley phys course
Yeah not that one
user116211
other is the one you quoted
05:42
I don't like the Berkeley physics course textbooks
user116211
@FenderLesPaul Baby reif!
except for Purcell of course
user116211
@FenderLesPaul Crawford?
Not a fan
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ fite me irl
bruh
user116211
@FenderLesPaul Actually Reif wrote the Berkeley one for undergrads and high-schoolers, I suppose
user116211
It is a copy of the original one + more intuitive examples and pictures; lots of pictures
did you know that Hawking-Ellis is used as a lullaby in Germany
and that the kids who can't do the problem sets in Arnold are thrown from the Zugspitze
user116211
@FenderLesPaul The most horrendous are Kittel's Mechanics and Wichmann's Quantum Physics
user116211
05:46
The later book really sucks
user116211
It is the worst book ever
user116211
on QM
haha
never heard of it before
05:47
Ask Wald what his favourite books are :P
Wald
Hawking-Ellis
Wald's other book
user116211
@FenderLesPaul It even tried to pack in this book QFT!
Wald's third book
oh he has a pop sci book
that's right
user116211
05:49
I hate pop sci
I'm going to ask Jim Hartle if he likes Wald's book
user116211
They make layman more lameman
I'm also going to ask Bob Wald if Wheeler ever called him a mathematician
user116211
The best layman book ever written by anyone is
@user36790 I think Zee is the best
Einstein Gravity
user116211
@0celo7 Zee?
@dmckee maybe you could run a GR course out of Zee
I'm not kidding when I say all you need is calculus and linear algebra for it
no bullshit ^
no topology
no crazy bundles
no bundles at all
I think the students would like that. What I don't know is if enough of them would do the out of class reading.
05:53
@dmckee If you're willing to trust me, get a desk copy of Zee.
user116211
Another layman book
user116211
One Two Three... Infinity: Facts and Speculations of Science is a popular science book by theoretical physicist George Gamow, first published in 1947, exploring some fundamental concepts in mathematics and science, but written at a level understandable by middle school students up through "intelligent layman" adults. The book is illustrated by Gamow. == Overview == Beginning with an exploration of elementary numbers, the book opens with a description of the "Hottentots" (Khoikhoi), said to have words only for "one", "two", "three", and "many", and builds quickly to explore Georg Cantor's theory...
It's a very gentle intro to GR that doesn't shy away from letting things get hairy. You can warn students about those sections.
Hairy as in computationally, not conceptually or mathematically.
@dmckee He reviews Newtonian orbits, the action principle
special relativity
no tangent spaces or any of that crap
Isn't Hartle better while doing the same stuff?
No, Hartle is shit
05:56
Zee sounds like a crackpot
user116211
@FenderLesPaul Thanks for the recommendation
@FenderLesPaul tenured UCSB crackpot
Lmfao
Does he still do research (Zee that is)?
user116211
0
Q: Hiii everyone... newton's law of cooling

Edita  DanielyanHii guys I am doing physics experiment which is to find How does the boiling time depend on the amount of water? For this I heated differrent masses of water having my 50 Degrees Celsius as my ultimate temperature for all the masses ( initial temperature of water is 22 degrees Celsius). My physi...

user116211
Hi
05:57
@FenderLesPaul dunno, he's p. old
I think he does quantum biology now
@dmckee a complaint about Zee is that his coverage of g waves is opaque
lol wtf he published in 2011
and then didn't publish until Feb of 2016
user116211
@0celo7:
@user36790 other book
@0celo7 I took GR from Hartle.
@dmckee your point?
He was putting together some notes that he hoped would become a book.
I guess they did.
@0celo7 No point at all, except that I hadn't notice that he got them published.
@dmckee oh
I wonder if he kept the Groucho Marx quotes.
06:00
I thought there was an implied value judgement there
Hartle did really cool stuff research wise
I did not do well in the class. Too many other hard classes the same term, so I didn;t give it the attention it needed.
I wish he didn't become emeritus
Emeriti can still teach if they want to.
there's this one prof I see going into the chem building every day
70+
cane
06:01
Some of my best graduate classes were taught by emeriti doing it for the love of the subject.
I've heard he almost died once during class
@dmckee Well, get a desk copy of Zee and Hartle.
Your students will enjoy Zee a lot, it's a higher level than Hartle, but I think he really prepares you well for it.
@dmckee but he won't take students
@0celo7 there's a prof here who cancels class if elevator is broken
because he can't walk up stairs
(math prof)
@dmckee Seriously, this is my no-shit recommendation.
user116211
@FenderLesPaul o.O
@FenderLesPaul It is very unusual for an emeritus professor to take on grad students. I'm not sure it is even allowed at most palces.
06:04
Yeah that's what I'm saying
I wish he didn't become emeritus
@dmckee You should consider supplementing with Weinberg.
His stuff on quantum cosmology would've been fun to work on
@dmckee For instance, Weinberg has a fantastic proof of the uniqueness of the Riemann tensor.
user116211
@dmckee :What do emiritus profs do?
give talks, go home
user116211
06:06
o.O
@FenderLesPaul seriously though, he's making his grad students give "guest lectures" in his 600 level class
@0celo7 your supervisor?
I'm not going to name names
he's teaching a class on his research, essentially
so his grad students are presenting contemporary topics
namely what they're working on
user116211
@0celo7 @dmckee @FenderLesPaul @Sᴋᴜʟʟᴘᴇᴛʀᴏʟ o/
06:13
@0celo7 Nicee
@user36790 In all seriousness the title often means they get to keep an office, so they come in a putter. Go to colloquia, work on monographs, teach the classes they always wanted to offer but the school would pay them to teach, chat with people around the department, try to learn that thing they always wanted to do.
@dmckee so once you've mastered GR again you can solve the problem of the Gauss theorem
and the orientation of that damn normal vector
@kevinTahN. wazzup o/
although you might need something higher level than Zee for that problem
 
1 hour later…
07:32
There are Professores Emeriti that are still extremely active in research, though they are rare. The best example I know is Elliott Lieb - 85 and still producing papers with impressive rate and quality
Wow!
Does he still teach?
08:02
Hello
08:59
@DanielSank Lol this is hopeless
@JohnRennie I don't know why you still try---unless this was your first "bout"... Everybody knows what the outcome of these discussions is.
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ no idea...probably not
09:19
@JohnDuffield The link you provided to Einstein's book: Relativity the special and general theory is an earlier edition which is missing appendix 5 please read it over and note his explanation of the importance of the invariant :)
09:37
You fool
Are you trying to explain things to JD
@Slereah that's not very nice
But is it wrong
Being right is not an excuse for being mean
4
this is a lesson we've learned the hard way here
09:43
fools are cool
Captain H. M. "Howling Mad" Murdock, played by Dwight Schultz, is a fictional character and one of the four protagonists of the 1980s action-adventure television series The A-Team. The character of Murdock was almost written out of the series before it aired, as the producers found the character too "over the top". The popularity of the character among the test audience however convinced the producers to keep the part of Murdock. Murdock appeared on The A-Team from the series beginning in 1983 until its cancellation in 1987. South African actor Sharlto Copley played the character in the 2010 film...
I wouldn't take fool as an offense...
I'm not "trying" to explain anything to him @Slereah He appreciates Einstein, so let Einstein explain it to him :P
@yuggib well then, we can all remember to call you a fool, but be wary of doing it to other people
Note that was added in 1954 just before his death.
FRANK DRUMMER
Out of a cell into his darkened space -
The end at twenty-five!
My tongue aould not speak what stirred within me,
And the village thought me a fool.
Yet at the start there was a clear vision,
A high and urgent purpose in my soul
Which drove me on trying to memorize
The Encyclopaedia Britannica!
Not just "mad" but: HOWLING mad :D
10:15
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ He does not mean the real Einstein
Only the Einstein in his mind
Possibly this one
I'm merely presenting THE evidence. Interestingly that book has 15 editions.
^ an italian improvement of the Masters' poem above
One of the main arguments of the book is that the newer concepts used by general relativity make Einstein's special theory redundant, and that once we're familiar with curved-spacetime arguments, SR just seems to get in the way. Since current "relativity" courses are based on special relativity, and current textbooks insist that SR has to be part of any credible larger theory, that message isn't likely to go down well with those tasked with teaching "syllabus" physics.
11:20
@DavidZ That's a little gem there.
11:34
The value of a "gem" is measured by how hard you have to work to find it.
PS I only learned that I only starting to understood the cause of moon phases just today
12:10
The phases of the Moon are the different ways the Moon looks from Earth over about a month. As the Moon orbits around the Earth, the half of the Moon that faces the Sun will be lit up. The different shapes of the lit portion of the Moon that can be seen from Earth are known as phases of the Moon. Each phase repeats itself every 29.5 days. The same half of the Moon always faces the Earth, so the phases will always occur over the same half of the Moon's surface. == Phases == There are 8 phases that the moon goes through. A new moon is when the Moon cannot be seen because we are looking at the unlit...
12:54
0
Q: Is QFT time symmetric, and how is it implemented?

SlereahIn electromagnetism, while the Maxwell equations are time symmetric, there is a choice to restrict solutions specifically to retarded potentials, imposing a time direction on the equations. And in QFT, as far as I'm aware, there is a restriction of what constitute an acceptable field to the small...

there it is
@Danu : the outcome of these discussions is that people learn some physics.
@Sᴋᴜʟʟᴘᴇᴛʀᴏʟ : I didn't say it was irrelevant, I said the physical real things he was talking about was light moving through space. And that the light-path length is the same in your parallel-mirror light clock and yours. That's the real thing that underlies the invariant interval.
@DavidZ : especially when he isnt right.
What if curved space and curved spacetime are the same
@EmilioPisanty : tell us how orbitals are completely fictional concepts again.
@0celo7 : well they aren't. Curved spacetime is inhomogeneous space. The inhomogeneity is not uniform, it decreases with distance from the massive body.
13:24
@JohnDuffield But what about curved spacetimes that are not homogeneous?
*that ARE homogenous, sorry
@JohnDuffield
Why does the Particle Data Group list mesons and baryons but not positronium or muonium
Why do you care?
What does IRL data have to do with wormholes
There are IRL data for wormholes
Although mostly to say "Nope, can't see any wormholes in the sky"
There was also that paper that listed effects to expect if there was wormhole and CTC production at the LHC
I suspect that it was a nope as well here
@Slereah I can't see any of those "particles" in the sky either
mb you should get some glasses then
They're all over the place
"In general relativity there is Thorn’s hoop conjecture which says that black holes form when, and only when, a mass M gets compacted into a region whose circumference in every direction is C < 4πGM [2]."
Hm
Never heard that one
" It has been proposed to use the Aichelburg-Sexl shock wave metrics to describe ultra-relativistic particles. Under collision of these waves one can expect a production of black holes"
"To get the transition amplitude between two particles and a black hole, or a wormhole one has to integrate the kernel (2) with the wave function ΨΣ′[h
′, φ′] describing two particles and the wave function ΨΣ′′[h′′, φ′′] describing black hole or wormhole. An expression for the wave function of the ground state of a black hole is considered in [7]."
Those seem to me pretty hopeful computations
"However if the fundamental Planck scale of quantum gravity is of the order of few TeVs"
So much hope
14:03
@0celo7 : A flat spacetime is where space is homogeneous. A curved spacetime is where space is inhomogeneous. A "homogeneous curved spacetime" is where the spatial inhomogeneity is homogeneous.
 
1 hour later…
15:05
@JohnDuffield Hmm, what do you call a spacetime with metric $g=-dt^2+a(t)(dx^2+dy^2+dz^2)$?
It's curved and homogenous!
No you fool
you wrote math
That will not do
15:22
Yesss, finally the silver QFT badge :)
@ACuriousMind Ignore the Eureka moment I @'d you
It was irrelevant
But the two theorems I sent you are important.
I'm going to try to generalize them later.
@ACuriousMind You know it might have to do with the strange structure group of the frame bundle on a Lorentz manifold.
Hmm, no. It's still a special group.
@ACuriousMind Am I missing something really obvious here?
@0celo7 How the hell am I supposed to know?
If I knew the actual derivation, I'd have pointed you to it long ago
But I don't care enough about this to spend time researching it
You should care :V
It's geometry
Ugh I wish I brought Lee with me.
15:45
@ACuriousMind There's probably a simple explanation in terms of sheaves.
16:03
@ACuriousMind do you really thing I did not know about T-symmetry violation :V
What do you think of me
Though i guess the answer will involve some T-symmetry stuff in the end, maybe???
I dunno
@Slereah Well, ask a more specific question! You're asking if QFT is defined to be time symmetric, the answer is it isn't, since there are T-violating QFTs.
Man
Did the best I could to specify what I meant!
If you're not asking about T-symmetry, I don't really know what you're asking
not quite sure how else to describe it
Well like I said
Maxwell's equation is T-symmetric
But we impose on it to only accept retarded solution
That kind of time orientation imposition
Isn't there an assumption that the momentum is always such that $p_0 > 0$
And if yes, how is it implemented, exactly
@Slereah That's precisely the starting point of Feynman-Wheeler, isn't it?
16:08
I suppose, yes, but Feynman Wheeler is kind of not really accepted nowadays, no?
So probably leaning more towards it being oriented somehow
@Slereah You have heard of the time ordering operator, right? ;)
True dat
Hm
Not an easy topic to think about with sleep deficit
I think you're right that there is a time orientation implicitly assumed to be given with the data in standard QFT. How else is the time ordering operator supposed to order stuff by $t_1<t_2$?
I should read that paper about AQFT in non-time orientable spacetimes
In particular, the LSZ formula sends $t\to\infty$, and this is distinct from $t\to -\infty$.
16:14
I'm sure that is the big topic they discuss
Oh well
Let's sneak out of the office
it's time for some week end
wtf are you two talking about
can we please focus on the important things in life
@0celo7 No, we're physicists.
@ACuriousMind huh?
Can you stop asking "huh?" every time I make a joke? :P
@ACuriousMind if you made jokes that were funny/made sense, I wouldn't have to
16:19
You don't have to. You can just ignore them.
@ACuriousMind Ok, Lee does not even address the issue of "outward/inward" for his proof of the divergence theorem
argh
@ACuriousMind Seriously, how the heck is outward-pointing defined?
16:34
Now suppose that an oriented (M, g) has a boundary 8M. Since 8M is basically a codimension one regular submanifold of M, the above con- structions can be applied to 8M so that 8M is Riemannian with induced metric. Since 8M has a global outward pointing vector field, we may nor- malize to obtain a global outward pointing unit normal field N along 8M. The orientation induced on 8M by the metric volume form iN volMlaM is exactly the induced orientation on 8M described previously.
AHHHHHH
PROOF DAMMIT
@ACuriousMind :
Maybe I should have said that "I don't care enough about this to spend time researching it" also means I don't care enough about it to spend time reading things about it in general.
@ACuriousMind Ok, will give you an update later.
@0celo7 That's really not necessary.
16:50
@ACuriousMind :(

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