The h Bar

@Sidarth My judgement is biased from having it used for a GR course with a terrible instructor, but generally I found that it focused too much special situations where you can avoid doing the formal math by physical reasoning, and told you too little about the general mathematical structure of the theory.

Sidarth

ohh....that is bad....

0celo7

The mathematical structure is just Riemannian geometry with a minus sign :P

Slereah

4:07 PM

Here's some relativity done without any french loans

anglish.wikia.com/wiki/Roomtide

"Roomtide, also Minkowski swathe or Minkowski swathetime, is a middlemost byset of roomlore. Roomtide binds the three roomspans or shapeworks with time. The Beholding of Onlay, as forsaid by Einstein, is said to work in roomtide."

0celo7

What...

Sidarth

wth??!

Slereah

Yeah so shut up about French :p

0celo7

@Slereah Lol this $300 book still says "cf. Hawking and Ellis (1973) for details"

Slereah

@0celo7 Don't they all

Physicists don't like to rewrite proofs

0celo7

4:09 PM

@Slereah This book goes into more details on the math

This is a mathematics text

Sidarth

@Slereah...you have a good book on relativity in mind?

Slereah

Depends what you want out of it

0celo7

But they say "cf. Hawking and Ellis" for the physics

Sidarth

@ACuriousMind is busy i guess

Slereah

Generally Wald is my recommendation

Wald's a pretty good all rounder

Sidarth

4:09 PM

Wald huh...

0celo7

@Sidarth Carroll.

ACuriousMind

@Sidarth Well, that too, but I just can't recommend a GR book.

Slereah

Carroll's also good

and the other guy

0celo7

Wald is a bit much, @Slereah, if he was considering Schutz.

Slereah

What's his name

German name

Something-mann

0celo7

4:10 PM

Straumann?

Slereah

Yeah

0celo7

Straumann is pretty terrible for an intro.

Sidarth

wald looks a bit old??

0celo7

@Sidarth That's true, he's not even on Steam right now.

Slereah

If you want an easy introduction to GR I recommend

0celo7

4:11 PM

Zee

Slereah

amazon.com/The-Geometry-Spacetime-Introduction-Undergraduate/dp/…

It goes pretty slow and starts out with 2D surfaces immersed in 3D

also it discusses acceleration in SR as an intermediary

0celo7

@Sidarth Go with Zee or Carroll. Those are in order of increasing difficulty.

They both explain the special theory.

Zee will also teach you some linear algebra and calculus of variations along the way.

Sidarth

i want to learn GR @0celo7

0celo7

I know, that's why I recommended two GR books.

Slereah

Otherwise we would recommend cooking books

0celo7

4:14 PM

@Slereah Have you heard of "Buseman functions"?

Slereah

Nope

Is it one of those special functions that are only useful for one equation

Sidarth

@Slereah ....cool down buddy

;)

Slereah

The emission of neutrinos on a pretzel shaped emittor

0celo7

Oh come on!

Sidarth

and thanks both!

Slereah

4:15 PM

I can check the Abramowitz

0celo7

The $300 book outsources proofs to O'Neil

Slereah

if u want

0celo7

@Slereah It's some GR thing

Slereah

Let's make a GR book with all the proofs

And sell it for

ONE MEELION DOLLARS

0celo7

@Slereah How about this

We take Steenrod, Hawking-Ellis, O'Neil, Straumann, Wald, Visser, Beem et al.

Tape them together

Then we have ALL of the GR proofs

Slereah

4:17 PM

Gonna be a big book

But

None have the proof for the Godel spacetime

0celo7

Christ

Oh and might as well throw in Bredon too

Gourgoulhon too

Slereah

Do we include Birrel Davies

And

Stephani

0celo7

Sure, also Wald QFT

Yup

Slereah

also experimental GR

0celo7

Jost Analysis, Jost PDE, Jost Geometry too

Slereah

4:20 PM

Can't really thing of any good source of experimental GR

0celo7

F. John's PDE book too

Slereah

Particle data group is the closest I have

0celo7

Print out the whole PDG website, stick it in there

Weinberg's new cosmology book

Slereah

Most of it is just meson crosssections

0celo7

Ok, this is a good book.

3507

4:21 PM

Who would read this 5000 page book?

0celo7

@Slereah I've got a few of them, I'll start taping

Slereah

If you want a good GDP book, try "Handbook of physics and chemistry"

0celo7

@3507 Dedicated students of GR

Slereah

That is the most GDP book

0celo7

@Slereah The one by CRC?

Slereah

4:21 PM

Yeah

0celo7

Yup

Slereah

Nothing but big tables of values for various shit

0celo7

every engineer has a copy of that

some even have multiple copies

in case the Koreans attack

they can rebuild the GDP after the war

Slereah

it can be used as a weapon, yes

3507

@0celo7 I found a book similar to that though for solid state physics, it's 2000 pages but it doesn't have problems... oh well.

0celo7

4:22 PM

@3507 oh, we would not have problems either

Slereah

That is one thing that is missing from GR

0celo7

we'll do all the problems in all of the books

Slereah

There's no solid state physics in GR

0celo7

solid state physics is GDP-heavy, GR is not

3507

well there is relativistic solid state physics.

Slereah

4:23 PM

Yeah but not GR

user54412

@Slereah You have to admit that English sounds much more awesome

Slereah

@ChrisWhite Sounds like a paper written by Gandalf

FenderLesPaul

sup

0celo7

@FenderLesPaul is anything missing?

FenderLesPaul

what?

3507

4:26 PM

@FenderLesPaul read $\Uparrow$

user54412

@Sidarth Depends what you're looking for. Note most of the regulars here are PhD-level mathematicians. Your profile doesn't say where you are in your studies, but if you're just looking to get a taste of GR to whet your appetite, Schutz is fine.

0celo7

Wald, Wald QFT, Straumann, Hawking-Ellis, Steenrod, Bredon, O'Neil, Visser, Beem et al., Birrel-Davies, Stephani, Jost Analysis, Jost PDE, Jost Geometry, Weinberg 2008

@FenderLesPaul Tape these together for the best GR book

FenderLesPaul

Choquet-Bruhat

Sidarth

@ChrisWhite ......intuitively answer.....Schutz or carrol

FenderLesPaul

Christhodoulou

0celo7

4:28 PM

Oh shit, forgot that one @FenderLesPaul

Never heard of the second

FenderLesPaul

It' the 500 page book that's dedicated to the proof that Minkowski space-time is a stable solution to the Einstein equations

0celo7

oh, right

link?

I was meaning to read that

FenderLesPaul

amazon.com/Nonlinear-Stability-Minkowski-Princeton-Library/dp/…

0celo7

$94

WHY

Why can't all books be $40 like Wald

dmckee

The publishers set the price they think will generate the most profit.

0celo7

4:31 PM

Or on Springer for $25

@dmckee I know, doesn't mean I have to be happy about it.

Beem et al. is $300 and it looks like the most complete book on spacetime topology there is

dmckee

And authors often pick presses for reasons other than the price you are going to get charged. Relationship with the editor. That's the only press interesting in a book on "Differential Foo Geometry" right now. Etc.

user54412

@Sidarth I read Schutz, then Carroll, then Wald, ... and now I do research related to GR, so it must have been a reasonable thing to do. If you can start with Carroll, that's great, but if it all seems over your head, start with Schutz. (Carroll's book grew out of these lecture notes, so you can get a taste for the level.)

FenderLesPaul

Because Wald's wife passed away so he doesn't need money anymore

0celo7

But I'll never read it now because I can't read a 600 page PDF

FenderLesPaul

except for research

dmckee

4:33 PM

The interesting question is, could a scientific publishing concern that aimed to minimize list prices consistent with profitablity be a viable thing?

0celo7

@dmckee Springer seems to manage.

Sidarth

@ChrisWhite thanks buddy..:)

0celo7

Their student prices are more than reasonable.

Sidarth

great advice

0celo7

Of course, I'm sure they fuck the university on the subscription price.

dmckee

4:33 PM

Kinda like Dover Press but for new works and taking advantage of internet driven workflow.

Springer doesn't suck on that front, but I'm really interested in something even better.

Only I have know idea how to support the beginning of such a project.

I suppose there is Kickstarter but it takes someone to run the project. Someone with the right skills.

0celo7

Welp, I have a crappy-looking stubble but if I try to shave it won't end well

@dmckee There was a post on reddit about what you would do if you had $4.2 trillion

Personally, I'd buy a fucking huge library

Sidarth

good night ppl

0celo7

with every book that could ever possibly interest me

Slereah

I don't think you're gonna spend 4.2 trillions on that

Those are "buy a country" numbers

you can just hire a bunch of mercenaries and take over a nation for that much

0celo7

I'd buy ACM a million copies of BBS

Slereah

4:40 PM

You will still have 4.2 trillions after that

that's how much that is

you could buy out every pair of pants on earth and still be the richest man ever

0celo7

I know

ACuriousMind

@0celo7 Uh, why?

0celo7

@ACuriousMind For the lulz

ACuriousMind

I won't be laughing about that :P

0celo7

Where would you put all of them, anyway?

That's a lot of paper

ACuriousMind

4:42 PM

Give them to the homeless? I dunno

Maybe I'd buy a nice fireplace

0celo7

Wow

I give you a nice gift and you just throw it away?

I would give @Slereah some money so he doesn't have to work

ACuriousMind

@0celo7 Maybe I also wall myself in with them and people will find my skeletal remains after digging though thousands of BBS copies

0celo7

@ACuriousMind :D

I could get the "monographs in mathematical physics" series in hardback

That would set me back several thousand.

@ACuriousMind Oh.

I would hire @Danu to typeset Milnor into LaTeX.

ACuriousMind

lol

0celo7

That might be the first reasonable thing I've said :D

ACuriousMind

4:46 PM

@0celo7 He could be your "personal time travel advisor"

Valentin Tihomirov

Is it right that a photon is a wave that collapses when detected?

0celo7

While he's at it, he could put Wald and HE into LaTeX

and fix the horrible notation in HE for vectors

ACuriousMind

@ValentinTihomirov No.

0celo7

And after all that, I'd still have 4.2 trillion

ACuriousMind

We have plenty of questions on the site on wave-particle duality, some of them should clear up your confusion

0celo7

4:48 PM

@ACuriousMind I could pay for PhD, too

Shit, I could just BUY any university I wanted

ACuriousMind

Why would you want to buy a university?

0celo7

They'd have to do research for me

We would have the most important questions of our time answered

"how do I stop my hands from sweating while playing BF4"

ACuriousMind

"how do I solve quadratic equations?"

0celo7

you're pretty mean, you know that

ACuriousMind

Yep, I know :)

0celo7

4:51 PM

I could BUY stack exchange

I'd be the god-king mod

instaban for gravitational wave questions

@ACuriousMind Think about it, if I bought, say, Harvard

I could have the physics and math faculty writing proofs for me all day

and the engineering faculty growing my wealth

ACuriousMind

@0celo7 What would be the difference to them writing the proofs as they currently do?

0celo7

@ACuriousMind the proofs would be on things that are of interest to me

PhD level quadratic equations, etc.

homotopy proof of Godel something something

ACuriousMind

I don't think mathematicians are so easily lured by money

They'll continue to prove whatever they are interested in

0celo7

@ACuriousMind with 4.2 TRILLION I could pay them 10 grand a day and still have 4.2 trillion

it's an obscene amount of money

of course, I'd invest 95% of it

I could BUY apple

@ACuriousMind then I buy their friends and family and torture them until they write my proofs

I would hire Trump as my personal adviser

ACuriousMind

Uhhhhhh

0celo7

4:56 PM

@ACuriousMind what

ACuriousMind

With that prospective future, I think I will indeed choose to perish inside my fort of BBS

0celo7

what prospective future?

you don't want me to be god-king :'(

ACuriousMind

@0celo7 That is an accurate observation

0celo7

@ACuriousMind hater

why wouldn't you want me to be happy :(

ACuriousMind

@0celo7 You have to learn how to be happy without godhood

0celo7

4:58 PM

I don't think that can ever happen

you can thank yourself for that

ACuriousMind

Huh?

0celo7

inferiority complex

Well, this was fun, but I shouldn't procrastinate any longer. Cheerio.

Danu

@0celo7 I'd gladly do it if someone paid me to do it

user54412

Thanks to LIGO I'm close to rep-capping for the third day in a row. All I need to do is keep this up for... 5 more months... and I can get the legendary badge.

Danu

Shaddap!

I'm so jealous

user54412

5:07 PM

Of John Rennie?

user54412

me too

Danu

Lol

Jacobadtr

hi

3507

does anyone here own a copy of jackson em (3rd edition)?

dmckee

@ChrisWhite You've more patience than I. For some reason I have lots of patience for silly questions from my students and very little for Internet People.

And for some reason I now want Internet People to be a band with a hit single SMTP.

Danu

5:14 PM

In other news, I AM ON HOLIDAYS

(FUCK YEAH)

Hey @ChrisWhite

3

Q: What is the structure of an event horizon for colliding black holes?

I would suspect that two black holes within close vicinity of one another would warp each other's event horizons such that the Schwarzchild's radius would no longer apply. Do the event horizons remain intact, during and after a collision or is there an intermediate, more complex structure? Wh...

user54412

That's a good question, but an involved one.

user54412

The shape of the horizon is coordinate-dependent.

Danu

@ChrisWhite Isn't there some kind of natural choice related to the final Kerr shape?

user54412

Even the topology (of the intersection with a sub-manifold) is coordinate dependent.

user54412

@Danu Sure, but the more unequal the two masses the worse that looks in the inspiral phase I'm pretty sure

user54412

5:25 PM

Or maybe it's the more equal they are?

user54412

@Danu Also, the last time I poured my heart and soul into a question about horizon shapes, it went essentially completely unnoticed.

Danu

@ChrisWhite Link? :P

user54412

This one -- I guess the problem was it was the right answer to the question, but the wrong question for the answer

Danu

@ChrisWhite Have you read the actual paper by Gannon?

Slereah

Just pick center of mass frame :p

and observer at infinity

Since that is what we are

user54412

5:36 PM

@Danu yes for that answer, but not line-by-line in too much detail

Danu

@ChrisWhite Did you get the essence of why higher-genus surfaces are not possible?

user54412

not really, or at least I don't remember having any sort of epiphany

HDE 226868

Did anyone else notice that Physics just passed 70,000 questions?

Danu

Yup

75 will be nicer

0celo7

80 will be even nicer

What's the growth rate for PSE?

Danu

5:49 PM

I think 75 is a nicer number than 80

Having 25 as a divisor is nice

user54412

By my counting this is #70k?

user54412

0

Q: What are some of the best Physics resources online?

Are there any sites similar to (in terms of function and quality) Paul's Online Math Notes, 17Calculus.com, or PatrickJMT.com, for Physics (besides Khan Academy)? I've googled this, but the sites I've found were described as high-school level, and I'm not sure if these would be adequate/appropri...

soft-question resource-recommendations education

Danu

:D

@ChrisWhite Oh god

user54412

@Danu 72 is even nicer

Danu

Hmm, you get a kick out of multiples of 24?

HDE 226868

5:50 PM

@ChrisWhite Oh.

Danu

I do also like the 2,3,4,6,8

user54412

so factorable <3

Valentin Tihomirov

upload.wikimedia.org/wikipedia/commons/thumb/d/d2/… says that when polarizer is at 45 degree, we loose $\sqrt 2$ of intensity/photons. That is because 1 is sqrt(2) shorter than the hypotenuse, which is used as source of the light. What if we turn the experiment upside down? What if we start to project the light from the leg of length 1 onto hypotenuse? Will we get more light at polarizer than falls upon it?

user54412

@HDE226868 Most of our milestones are homework, so perhaps an improvement?

HDE 226868

@ChrisWhite Fair enough.

dmckee

5:56 PM

"Will we get more light at polarizer than falls upon it?" Of course not. Where would the energy come from?

More generally I don't follow your argument but I think that you have misunderstood where Malus' Law (i.e. how polarizers effect intensity) comes from.

The angle is always measured relative the polarization direction of the incoming beam.

0celo7

6:16 PM

@dmckee Energy is not conserved in GR :^)

@adults do I need to cover a cotton dress shirt while ironing or will it be fine

I know I have to cover wool pants

dmckee

6:34 PM

@0celo7 I iron cotton shirts uncovered every time I iron them (not often). Never burned one yet. But you do need to keep the iron in motion.

0celo7

Hopefully I can get it out the dryer quickly and it won't have deep wrinkles yet

@dmckee How much does the topic of my undergrad thesis matter for getting into grad schools

user54412

Does revision 3 count as self-vandalism?

user54412

6:58 PM

Also, is anyone else bothered by how Einstein gets credit for so many things he got wrong?

user54412

Cosmological constant: said it was there, then said it wasn't

0celo7

@FenderLesPaul that stability book

user54412

Gravitational waves: said they exist, then said they didn't

user54412

Black holes: said they didn't exist

0celo7

is it just pages and pages of PDE or is there actual geometry there

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