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vzn
vzn
3:00 PM
@BalarkaSen part of english culture (not just american!) is the "melting pot" :P
 
Tanuj
Tanuj
@BalarkaSen You literally know so much about English literature / Writers , but still don't appreciate it. I mean I wouldn't like it if I was English.
 
John Rennie
John Rennie
Joseph Conrad blatantly wasn't English. He was Polish.
Born Józef Teodor Konrad Korzeniowski
 
Balarka Sen
Balarka Sen
Yeah, he didn't come to Britain until his thirties or something IIRC
It's not moving the goalpost to call non-examples as non-examples
 
John Rennie
John Rennie
Karl Marx - he was English. I mean he's buried here!
 
vzn
vzn
lol @#%& trollish hairsplitting. wikipedia refers to him as polish-british in 1st few lines case closed :P en.wikipedia.org/wiki/Joseph_Conrad
 
Tanuj
Tanuj
3:02 PM
@BalarkaSen How do you know all of this OMG that's incredible.
@JohnRennie The economist ? Oh the father of economy
 
Balarka Sen
Balarka Sen
@vzn You're up for a debate you haven't researched clearly about. The birthplace, descent and early life of a writer is a heavy influence on the author's writing.
 
Tanuj
Tanuj
Oh and what about Jane Austen ?
 
John Rennie
John Rennie
You're up for a debate you haven't researched clearly about - that would be a first
Jane Austen!! - :: John faints away in shock ::
 
Tanuj
Tanuj
@JohnRennie lol what happened ?
 
Balarka Sen
Balarka Sen
@Tanuj Oh I mean I appreciate it. I was making a slightly controversial statement about the proportion of English language literature written by British people (I'm open to statistical refutations of it, though).
 
John Rennie
John Rennie
3:05 PM
George Eliot
The other miserable bastard I can't remember ...
 
Balarka Sen
Balarka Sen
@vzn If you think it's waste of your time you should not parttake in it :P You're wasting nobody but your own time
 
John Rennie
John Rennie
Google Google
aha, Thomas Hardy
 
Tanuj
Tanuj
@BalarkaSen cool , cool. I'll be taking book recommendations from you after May for sure.
John Keats ?
 
John Rennie
John Rennie
Not a novellist
 
Tanuj
Tanuj
@JohnRennie Okay , only novelists ?
 
vzn
vzn
3:07 PM
@Tanuj yes, surprise! poetry is literature :)
 
Tanuj
Tanuj
Well I was gonna William Wordsworth as well
 
John Rennie
John Rennie
I think it's novellists - @BalarkaSen do poets count?
 
Balarka Sen
Balarka Sen
The British had a thing for Romanticist poetry, I'll give you that. Keats, Shelley, Byron - yes, Wordsworth. I'd add William Blake in the mix, because he's one of the better of the post-Romantic generation
@JohnRennie I think there's no reason for it to not count
 
John Rennie
John Rennie
@Tanuj I wandered lonely as a soliton
 
vzn
vzn
lol re moving the goalposts let the record show the challenge was stated wrt literature
36 mins ago, by Balarka Sen
@CaptainBohemian It was a half-joke. The more serious half is something along the lines of, Britain contributed very little to the English language literature in the past two centuries.
 
John Rennie
John Rennie
3:08 PM
OK poets count
 
Balarka Sen
Balarka Sen
@JohnRennie HAH
Amazing
 
John Rennie
John Rennie
There are shedloads of influential (but tedious) English poets
 
Tanuj
Tanuj
Oh and Wayne Rooney !
 
John Rennie
John Rennie
By the vzn definition T. S. Eliot was English!
 
Tanuj
Tanuj
iirc he has an autobiography :p
 
Balarka Sen
Balarka Sen
3:10 PM
Let's agree to say that vzn's definition is useless garbage
 
vzn
vzn
sigh, seems you guys just like to argue sometimes, not nec wrt logic/ fairness etc :( ps stated no "defn"... again words in my mouth, 2 vs 1 etc
 
John Rennie
John Rennie
That would also be a first :-)
 
Balarka Sen
Balarka Sen
You know, it's not easy to determine what Eliot's influences was
 
Tanuj
Tanuj
Alright guys , I'll take your leave now , really so much of a learning experience , I got to know about so many great authors , I'd even forgotten some.
 
Balarka Sen
Balarka Sen
His family was one of the bigshot families of that time
 
John Rennie
John Rennie
3:11 PM
@BalarkaSen near fatal doses of psychedelic drugs?
 
Balarka Sen
Balarka Sen
The Eliot family
They established the MIT I think
@JohnRennie lol
 
vzn
vzn
@Tanuj thx for your nice contributions, some of my faves, nice to be reminded :)
 
Tanuj
Tanuj
@vzn Yea , same here ! Really enjoyed this ! Looking forward to similar discussions in future :)
 
vzn
vzn
lol "discussions" yeah! :) :P
 
Balarka Sen
Balarka Sen
Oh, er, I guess D. H. Lawrence is also a fair name
 
Tanuj
Tanuj
3:13 PM
@vzn I know :p
 
John Rennie
John Rennie
@BalarkaSen Women in love - nudge, nudge, wink, wink
 
Balarka Sen
Balarka Sen
lool
 
vzn
vzn
@Tanuj always amazes me how some foreigners know the culture better than insiders, its a bit shameful (on the insiders)... :| good ol isolationism & all that etc
 
John Rennie
John Rennie
Who wrote the one about the gamekeeper?
 
Tanuj
Tanuj
@vzn I guess its just about personal interest and nothing more than that.
@vzn Are you English too ?
 
vzn
vzn
3:15 PM
@Tanuj ok nevertheless you are honestly better informed than many english students.
@Tanuj US/ american. a lot of british literature is studied in our english classes.
 
John Rennie
John Rennie
Aha, Lady Chatterley's Lover. That was Lawrence too! One track mind that lad.
 
Tanuj
Tanuj
@vzn nice :)
 
Balarka Sen
Balarka Sen
@JohnRennie Oh god
 
John Rennie
John Rennie
I bet you're sorry you started this now :-)
 
vzn
vzn
@Tanuj are you at the university? what are you studying?
 
Tanuj
Tanuj
3:16 PM
@vzn Aha , I didn't know that. How old are you ?
 
vzn
vzn
@Tanuj uh, let me just say ~2x the university dudes in here. o_O
 
Tanuj
Tanuj
@vzn Not yet in college , hopefully will be getting in one in about 3 months time
 
Balarka Sen
Balarka Sen
@JohnRennie Now that made me wonder who wrote Fanny Hill.
 
vzn
vzn
@Tanuj cool, glad to hear it (coincidentally similar to BaSe), think youll make great student what do you want to study?
 
Balarka Sen
Balarka Sen
John Cleland. British, apparently
Influential? Up to the reader!
 
John Rennie
John Rennie
3:18 PM
Google, Google - 1748. Doesn't really count.
 
Tanuj
Tanuj
@vzn What is BaSe ? And well , I'm not sure but computer science.
 
Balarka Sen
Balarka Sen
Yea, well, I did say two centuries. Fair.
 
Tanuj
Tanuj
@vzn Ah , I see.
lol :p
 
vzn
vzn
lol :P
@Tanuj good choice, way2go, try out Computer Science sometime :)
 
Tanuj
Tanuj
@vzn Yup , I will once I get to study it .
 
vzn
vzn
3:20 PM
@Tanuj the great thing about Computer Science is you can study it anytime these days & it helps to do that too :)
 
Tanuj
Tanuj
@vzn do what ?
 
vzn
vzn
@Tanuj lol study CS. the internet awaits. etc
 
Tanuj
Tanuj
ok. Well I would love to , after I'm finished off with my exams and stuff
 
vzn
vzn
@Tanuj yeah study hard good luck nice chatting bye
 
Tanuj
Tanuj
@vzn Thanks dude , have a good one . Bye
 
vzn
vzn
3:23 PM
sure yw :)
 
Balarka Sen
Balarka Sen
It's probably hard to determine the various interlinks between actual literary influences. I'd call Samuel Beckett (Irishman) one of the best playwriters of the century - but it's really hard to say that without giving credit to the absurdist theater that originated as Elizabethan absurdism.
So, prejudices aside, it's probably not as black-and-white.
 
John Rennie
John Rennie
Speaking of cultural landmarks, it appears Netflix has just bought the rights to all the Monty Python films and TV series.
 
Balarka Sen
Balarka Sen
I mean, shit, modern surrealism has fed off Lewis Carroll
Yeah vzn linked that earlier
 
0celo7
0celo7
@JohnRennie NetFlix?
 
John Rennie
John Rennie
@BalarkaSen ah, one of the downsides of having people on ignore is you miss the occasional useful thing they post :-)
6
 
0celo7
0celo7
3:30 PM
oooooooooooo
 
Balarka Sen
Balarka Sen
@JohnRennie Hahaha
 
John Rennie
John Rennie
@0celo7 huh?
 
0celo7
0celo7
@JohnRennie the F is not capitalized
 
John Rennie
John Rennie
Aha, OK.
 
Balarka Sen
Balarka Sen
@0celo7 You meant, "the f is not capitalized"
 
0celo7
0celo7
3:32 PM
whatever
 
Balarka Sen
Balarka Sen
git rikt
 
0celo7
0celo7
fine, smartass, do this proof for me
 
John Rennie
John Rennie
@BalarkaSen the pedantry chat room
3
 
vzn
vzn
huh? lol
2 days ago, by John Rennie
I love the way this chat room discusses real issues (not necessarily just physics) in a useful and informative way. With all the silliness and random flags we've been having recently it's easy to lose track of just how awesome this room can be.
 
0celo7
0celo7
@vzn please roast john
 
vzn
vzn
3:37 PM
@BalarkaSen btw re that theres this thing called "black + white thinking"... o_O
@0celo7 lol easy target but too risky, he trashed a lot of msgs lately, lucky not mine o_O
 
0celo7
0celo7
I would support you
@JohnRennie is my arch nemesis
3
yes, I agree he is a fundamentalist
 
vzn
vzn
@0celo7 lol no kidding really why is that
 
0celo7
0celo7
exactly
 
John Rennie
John Rennie
@0celo7 rubbish, I am the kindest and most sensitive person I know
5
 
vzn
vzn
@0celo7 ahem ok since you point this out, there was some other stuff he said that deserves to be "addressed"...
 
John Rennie
John Rennie
3:40 PM
(though admittedly I might be biased)
 
0celo7
0celo7
@vzn oh?
 
vzn
vzn
@0celo7 reviewing recent comments he seems to draw the line between physics + philosophy in joking/ yet a bit )( odd ways at times. this relates to the (longtime) JD stigmatizing (a topic youve expressed interest in, though probably mostly facetiously).
@BalarkaSen f that :P
 
John Rennie
John Rennie
3:56 PM
Lunch - stuffed veg, very healthy!
 
vzn
vzn
Mar 9 at 16:29, by ACuriousMind
This is a chat, not a diary.
 
Shing
Shing
anyone familiar with the programming langauge Julia?
 
0celo7
0celo7
@vzn oooooooooooooooooooooooooooooooooo
@JohnRennie you got destroyed fucking lmao
@BalarkaSen come see this
 
John Rennie
John Rennie
@0celo7 I did? Oh well :-)
 
0celo7
0celo7
@JohnRennie Yes.
Mar 9 at 16:29, by ACuriousMind
This is a chat, not a diary.
No food pictures please
 
John Rennie
John Rennie
4:11 PM
@0celo7 was that aimed at me?
 
vzn
vzn
← lol, sometimes likes/ uses "diary" "feature" of chat, sometimes not :P
 
Semiclassical
Semiclassical
...yeah, me too
though there's always an option to make a new room for such things, and that's what I do if it's something truly obscure (or if it's likely to be tedious)
for instance, I wanted to do some somewhat tedious manipulations of an integral representation the other day, so I created a new room for that
 
vzn
vzn
@Semiclassical think new rooms are one of best chat room features, yet seems ppl rarely create new rooms or participate in them, its some strange SE psychology tendency
 
Semiclassical
Semiclassical
yeah, we tend to rely on the status quo of the room that are already there
 
0celo7
0celo7
@JohnRennie vzn redirected it
and you got destroyed
 
vzn
vzn
4:20 PM
@0celo7 lol impossible to "destroy" room owners/ co-mods they have (lethal) superpowers o_O
 
John Rennie
John Rennie
Oh well
 
Semiclassical
Semiclassical
chat jiu jitsu
 
0celo7
0celo7
@Semiclassical do you randomly know a non-mathematica way of proving $x\cosh x\le 1+x$ for $x\ge 0$
 
Semiclassical
Semiclassical
hm
$$x \cosh x-x=\frac{x}{2}(e^{x}-2+e^{-x})=\frac{x}{2}(e^{x/2}-e^{-x/2})^2 =2x\sinh^2\frac{x}{2}$$
But that doesn't seem like it'd imply an upper bound of 1.
 
0celo7
0celo7
$x\cosh x$
 
Semiclassical
Semiclassical
4:25 PM
thanks
 
0celo7
0celo7
maybe that has a maximum at 1
 
Semiclassical
Semiclassical
but I don't think this bound is true. cosh(x) grows like e^x/2 for large x
and that alone is enough to ensure that 1+x can't bound it
 
0celo7
0celo7
 
John Rennie
John Rennie
Taylor expand cosh x?
 
Semiclassical
Semiclassical
oh, coth not cosh!
big difference
 
0celo7
0celo7
4:27 PM
oh
typo lol
 
Semiclassical
Semiclassical
coth tends to 1 for large x
 
0celo7
0celo7
yes, but from above
 
Semiclassical
Semiclassical
right.
 
0celo7
0celo7
so this isn't immediately clear
 
Semiclassical
Semiclassical
oh, sure. but it makes it at least plausible
anyways, now the manipulations to be made are a bit different though still easy
first: $\coth$
oh good, latex knows it
$$x\coth x-x = x\left[\frac{e^{x}+e^{-x}}{e^x-e^{-x}}-1\right]= x\left[\frac{2e^{-x}}{e^x-e^{-x}}\right] $$
 
0celo7
0celo7
4:30 PM
I got $2e^{-x}$ in the numerator
 
Semiclassical
Semiclassical
yeah, you're right
so that's $x e^{-x} \csch x$
oh ffs latex, you know coth but not csch?
 
Slereah
Slereah
@0celo7 Earman says that the Bruhat theorem isn't enough to guarantee that spacetime from initial conditions is deterministic
And that the spacetime being maximal isn't the same as being determinism maximal
Does that sound like a thing u would know
 
0celo7
0celo7
no
but the real issue is that Bruhat--Geroch only works for a GH spacetime
 
Slereah
Slereah
Well not too surprising
But he claims that this may not be enough
i think
 
Semiclassical
Semiclassical
for reference
 
Slereah
Slereah
4:33 PM
and that's the whole reason behind the "hole-free" issue
 
0celo7
0celo7
@Semiclassical So is it obvious that $xe^{-x}csch(x)$ is bounded above by 1 lol
 
Semiclassical
Semiclassical
yeah, that's the question ain't it
or again equivalently $\frac{2}{e^{2x}-1}\leq \frac{1}{x}$ for positive $x$
 
0celo7
0celo7
Ah, easy
 
Semiclassical
Semiclassical
yeah, I see it now
 
0celo7
0celo7
It's decreasing
 
Slereah
Slereah
4:35 PM
Really why do we mourn for Hawking when Geroch is still around
Geroch is pretty great
 
0celo7
0celo7
And 1 at 0
 
Semiclassical
Semiclassical
if you rearrange what I just wrote, that's just $e^{2x}\geq 1+2x$ for $x\geq 0$
 
Balarka Sen
Balarka Sen
$e^x \geq 1 + x$ is one of the most useful inequalities of all time
 
Semiclassical
Semiclassical
which is just the usual convexity bound
 
Balarka Sen
Balarka Sen
For positive $x$
 
Semiclassical
Semiclassical
4:36 PM
ya really
 
Slereah
Slereah
Apparently there's another book of weird GR issues where Geroch wrote an article on the topic
"Foundations of spacetime theories"
It has Earman, Geroch and Malament
That sounds great
 
Semiclassical
Semiclassical
actually, isn't that valid for all real $x$? It's not useful for $x<0$ here because we divide by $x$ which can be negative
 
0celo7
0celo7
Yeah I was trying to use that one but it was going the wrong way around
 
Semiclassical
Semiclassical
no, I mean $e^{x}\geq 1+x$
 
0celo7
0celo7
oh, yes, of course
 
Balarka Sen
Balarka Sen
4:38 PM
Yeah I guess so
 
Semiclassical
Semiclassical
but you end up rearranging that and divide by $x$ in the process
 
0celo7
0celo7
it's a tagent line of a convex graph
 
Balarka Sen
Balarka Sen
Right
 
Semiclassical
Semiclassical
which would reverse the inequality for $x<0$
so I think this completely addresses it
So: $e^{2x}-1\geq 2x$ for all $x$
 
Balarka Sen
Balarka Sen
@0celo7 what is this, supa hot fire?
 
0celo7
0celo7
4:40 PM
@BalarkaSen I love it
@vzn well done
 
Semiclassical
Semiclassical
then $\frac{2x}{e^{2x}-1}\leq 1$ for $x\geq 0$
where we need the restriction $x\geq 0$ since $e^{2x}-1<0$ for $x<0$
and then adding $x$ to both sides gives the original bound to be shown, woo
 
Balarka Sen
Balarka Sen
I don't see why stating that stuffed veg is very healthy for lunch is equivalent to writing a diary, @0celo7 @vzn
That seems poor philosophical equivalence by extrapolation
 
Semiclassical
Semiclassical
I think the proper comparison is less "like writing a diary" and more "like twitter"
 
Balarka Sen
Balarka Sen
Clearly you two haven't been purplepilled by Jordan B. Peterson well enough
 
Semiclassical
Semiclassical
@0celo7 so that was fun.
 
0celo7
0celo7
4:44 PM
 
Balarka Sen
Balarka Sen
@Semiclassical Honestly, there's nothing per se wrong with stating "I'm doing X right now" on the chat. I didn't really get what ACM is bothered about in the original objection but I didn't bring it up because it felt like a minor issue
 
Semiclassical
Semiclassical
nice
I don't either, really. I can sorta see an argument for it as 'spam' but ehhh
 
Balarka Sen
Balarka Sen
yeah, spam is more like, if you're like, writing a full page of diary
 
Semiclassical
Semiclassical
This isn't like the main site where the aim is to have a curated collection of content
 
0celo7
0celo7
I think the actual context was one of Secret's mental breakdowns, no?
 
Balarka Sen
Balarka Sen
4:46 PM
@0celo7 No, this was not about Secret's messages
It was to Cows
Who writes what he's doing on a regular basis on the chat to an empty audience
 
0celo7
0celo7
ah, yes
 
Semiclassical
Semiclassical
tbh I have the latter on ignore.
 
0celo7
0celo7
153 pages
 
Semiclassical
Semiclassical
I usually can't understand Secret but at least he says interesting things.
 
0celo7
0celo7
I still have the Mega Calculation to do
 
Balarka Sen
Balarka Sen
4:48 PM
@Semiclassical I agree with this
If he makes his "idea-blogs" shorter to fit in the context of chat, I think he's a perfectly fine member of the chat
Or rather, if he opens a blog himself for extended write-ups and then links it along with a summary
 
Semiclassical
Semiclassical
There's a limit, of course.
Or even just use a sub-room consistently for that purpose
 
0celo7
0celo7
he does have one
 
Balarka Sen
Balarka Sen
True
 
0celo7
0celo7
it's like the room in ass creed 1 when you have the vision thingie
 
Semiclassical
Semiclassical
lol
 
Slereah
Slereah
4:50 PM
@Semiclassical stop those lies
 
0celo7
0celo7
@Slereah Not Nice.
Get banned.
 
Semiclassical
Semiclassical
I made a room recently in order to have a spot to ramble about stuff
 
Slereah
Slereah
If it's a crime to say that Secret only does inane rambling then let history remember me as a criminal
 
Semiclassical
Semiclassical
which I haven't used much
but it's there if I need it
 
Balarka Sen
Balarka Sen
@Slereah I'd use a (milder version of that) for Kenshin, not Secret
 
Slereah
Slereah
4:52 PM
@BalarkaSen Kenshin is even worse because he's smug about it, too
He's like a teenager that just found a wikipedia page about basic philosophy concepts and thinks himself like the wisest man who ever lived
 
Balarka Sen
Balarka Sen
Lol
I won't publicly say if I agree with that description
 
Anonymous
Secret normally listens if you tell him to stop and take his messages elsewhere. I don't see any bad intentions there. Some people just like to talk!
 
Anonymous
Kenshin is a different case altogether
 
0celo7
0celo7
@Slereah is just a hater
 
Semiclassical
Semiclassical
I'd put it like this. One of my intellectual heroes is Euler. That's not just because he did so much, but because he was so adventurous in what he did
 
Slereah
Slereah
4:55 PM
it's true
 
Balarka Sen
Balarka Sen
@0celo7 I'd respond to that but I'm too lazy to actually bring myself to do it
 
Slereah
Slereah
i am filled with hate
I am basically the Grinch of physics
 
Semiclassical
Semiclassical
A lot of what he did is (rightly) longer considered to be rigorous
 
John Rennie
John Rennie
Enough with the character assassinations (that's my job! :-)
 
Semiclassical
Semiclassical
But he was willing to try things, see what they did, and publish it for the world to see
 
Balarka Sen
Balarka Sen
4:56 PM
@JohnRennie I mean we're having a public discourse, aren't we? That's what the mods wanted!!
 
vzn
vzn
@BalarkaSen cows is relatively new to the chat & think his lines are sometimes "contextless" but think it could be more hospitable to him, sometimes think its a wonder that anyone turns into regulars around here. think its great that ppl share interesting stuff going on with them personally "to a pt" etc
 
Semiclassical
Semiclassical
So Euler was more of an explorer/pioneer, by contrast with someone like Gauss who was more of a conqueror (not sure that's the best way to put it)
 
John Rennie
John Rennie
@BalarkaSen I think it would be different if Secret or Kenshin were here and you were asking them to stop. As it is you're just slagging them off.
 
0celo7
0celo7
Oh, we don't have a problem trashing Kenshin because he's smug
 
Balarka Sen
Balarka Sen
I wasn't slagging Secret
I just said I like him
which I do
 
John Rennie
John Rennie
4:58 PM
2 mins ago, by John Rennie
Enough with the character assassinations (that's my job! :-)
 
Anonymous
Same ^
 
Balarka Sen
Balarka Sen
@vzn I think what Cows says is ok, tbh
Anyhow I have to get going now
 
Semiclassical
Semiclassical
I'm very much an advocate of using ignore
 
0celo7
0celo7
@BalarkaSen Disagree.
 
vzn
vzn
@0celo7 lol hes interested in elliptic fns, what are you, an elitist? :P
 
Anonymous
5:00 PM
Cows is beyond my human understanding :P He seems sweet though
 
0celo7
0celo7
very elite.
 
Secret
Secret
(a couple of hours later...) nah I don't think I have enough foundations on analysis to solve that integral functional equation. I'll do that later, now to do a little bit more chem and then go to sleep
 
vzn
vzn
@0celo7 ok you @#%& elite(ist) undergraduate :P
 
Anonymous
Okay well let's stop talking about people behind their backs XD
 
vzn
vzn
@Blue ok. blue is the worst, lol :P
 
0celo7
0celo7
5:01 PM
@vzn for sure.
 
Secret
Secret
lol I am perfectly fine on that, as long people are saying what they actually think
 
0celo7
0celo7
he tried to kill @diobuceulb
 
vzn
vzn
@0celo7 diobuceulb, aka the chameleon, seems to ask for trouble o_O ... (but, trying to think of something nice to say) he has a kickass cool id :)
 
Anonymous
diobuceulb was a good friend. I miss him tbh. Circumstances just turn out to be bad sometimes and people misunderstand you. Maybe someday...
 
vzn
vzn
@BalarkaSen example of some of his at-times "contextless" writing: cutting edge coding, public speaking, math + physics research, & interviewing with top silicon valley companies. etc... honestly think he might be good for an AMA esp given no volunteers for dry spell over ~½yr... o_O
 
Slereah
Slereah
5:18 PM
"One can, within Newtonian mechanics, construct a solution representing two rocket ships which bounce between them a mass point with ever increasing speed. The result is that the rocketships accelerate in opposite directions; if the speeds are adjusted correctly, the ships can be made to escape to the "edge" of our Euclidian space in finite time, leaving nothing behind."
It's the dreaded bouncy double space invader whammy
 
vzn
vzn
@Slereah (lol missed that) memes are the scourge of this room and far @#%& worse than "inane rambling" :P
 
Semiclassical
Semiclassical
reminds me of a fun problem in special relativity
 
Slereah
Slereah
@vzn You can take them from my cold dead hands
 
vzn
vzn
@Slereah its like a GR pinball or video game, hey someone should invent that :)
 
Slereah
Slereah
Well no, it's written specifically as Newtonian!
And the infinitely accelerated GR curve doesn't go to infinity in finite time
 
Semiclassical
Semiclassical
5:22 PM
"Two spaceships float in space and are at rest relative to each other. They are connected by a string. The string is strong, but it cannot withstand an arbitrary amount of stretching. At a given instant, the spaceships simultaneously (with respect to their initial inertial frame) start accelerating (along the direction of the line between them) with the same acceleration. (Assume they bought identical engines from the same store, and they put them on the same setting.)"
 
Slereah
Slereah
It goes asymptotically to a null curve
 
Semiclassical
Semiclassical
Will the string eventually break?
 
Slereah
Slereah
in finite proper time
 
bolbteppa
bolbteppa
$(i \frac{\partial}{\partial t} - e A_0) \phi = \dfrac{1}{2m} \vec{\sigma} \cdot (\mathbf{p} - \frac{e}{c} \mathbf{A})^2 \phi - \dfrac{1}{(2mc^2)^2} \vec{\sigma} \cdot (\mathbf{p} - \frac{e}{c} \mathbf{A})(i \frac{\partial}{\partial t} - e A_0) \vec{\sigma} \cdot (\mathbf{p} - \frac{e}{c} \mathbf{A}) \phi + \dots$
 
vzn
vzn
@Slereah yeah pinballs (one of my faves) are very newtonian but the "dreaded bouncy double space invader whammy" maybe got me carried away a little )( and sounded even GR like. re acceleration, speeds, rocketships, euclidean space etc
 
bolbteppa
bolbteppa
5:24 PM
That's the Dirac equation in an EM field expanded in powers of $1/c$, wtf does it physically mean to expand in powers of $1/c$, with the first order term reproducing the Pauli equation
 
Slereah
Slereah
The horrible space invader scenario in GR is Anti-de Sitter space
 
vzn
vzn
@Semiclassical lol it IS GR! :)
 
Slereah
Slereah
Where null curves go to infinity in finite time
 
vzn
vzn
← went on gym water slides + dry/ steam room + hot tub + indian restaurant with indian CS Msc student last nite + almost ran red light o_O
 
0celo7
0celo7
5:51 PM
@Blue no, the ship has sailed
 
Anonymous
6:05 PM
@0celo7 No grudges on my side.
 
Slereah
Slereah
It's pretty hard reading about spacetime holes because I know that most old papers are wrong
Geroch just claimed that Minkowski space doesn't have holes, but it was later proven that it was
I have no idea if there's a definition of holes that holds up in modern times
Although I've seen some paper with a definition that has every globally hyperbolic inextendible spacetimes as hole-free
which sounds reasonable
Actually, maybe I should send an email to Krasnikov
I've got his emails and he seems responsive
and he seems very invested in that business
 
vzn
vzn
@0celo7 lol "ship" returns 4d
 
Sir Cumference
Sir Cumference
6:30 PM
@JohnDuffield Do you care for cosmology?
 
Balarka Sen
Balarka Sen
6:51 PM
@Blue Why would diobuceulb call me "the opposite operator of cool and good" when I'd NEVER call him "get banned"? Oh well, I try so hard to be his friend - and maybe someday that will happen!
 
Qmechanic
Qmechanic
-1
Q: Is there another universe which is made up of antimatter, in large amounts like ours is made up of matter?

PitifulStudentCan it be possible that in the big bang, not one, but two universes were formed, one formed of matter, and the other formed of antimatter? It seems logical to me that since our universe is formed of matter, there must be some universe made of antimatter, so that a sort of an equilibrium is mainta...

universe big-bang antimatter thought-experiment
Primarily opinion-based?
 
Anonymous
@BalarkaSen I'm with DJT on that one. :P
 
galmeida
galmeida
"
"One can, within Newtonian mechanics, construct a solution representing two rocket ships which bounce between them a mass point with ever increasing speed. The result is that the rocketships accelerate in opposite directions; if the speeds are adjusted correctly, the ships can be made to escape to the "edge" of our Euclidian space in finite time, leaving nothing behind."
It's the dreaded bouncy double space invader whammy"
 
Tanuj
Tanuj
7:20 PM
@Blue Hi bro , do you remember any tricks or tips for remembering inorganic ?
 
Anonymous
@Tanuj Buy gigantic chart papers
 
Anonymous
And color pens/pencils
 
Tanuj
Tanuj
Uhm okay. I see where you're getting at
 
Anonymous
Yeah. And just write down all the NCERT stuff in brief
 
Anonymous
That's pretty much all you need to do
 
Tanuj
Tanuj
7:28 PM
also what about ydse ? Even if I remember the formulae , I can't solve its questions
 
Anonymous
YDSE is easy peasy
 
Anonymous
Maybe do more example problems
 
Semiclassical
Semiclassical
7:55 PM
random aside for myself: $\int x_i x_j \,d\Omega$ should be rotationally invariant, so $\int x_i x_j \,d\Omega=C\delta_{ij}$. taking the trace then gives $3C=\int 1\,d\Omega=4\pi\implies \int x_i x_j \,d\Omega = \frac{4\pi}{3}\delta_{ij}$
 
Semiclassical
Semiclassical
8:11 PM
In particular, $\int z^2 d\Omega=\frac{4\pi}{3}$ on the unit sphere. But it's probably silly for me to do it this way since in spherical coordinates it's just $$\int_0^{2\pi}\int_0^\pi \cos^2\theta\sin\theta\,d\theta d\phi =2\pi\left[-\frac{1}{3}\cos^3\theta\right ]_0^\pi=\frac{4\pi}{3}$$
 
0celo7
0celo7
9:03 PM
@ACuriousMind I need algebra help (quadratic equation)
@Semiclassical halp
 
Cows
Cows
Out of curiosity, what does the quadratic equation look like?
just curious as I know you can definitely solve it lol
 
0celo7
0celo7
$$0\ge -(C_8(1+\epsilon^{-1})\rho^{-2}-4H_2\sigma +(2(n-1)^2+\epsilon)K+C_9\eta)G+(2-\epsilon)G^2+2H_1^2\sigma^2-\epsilon H_2^2-C_{10}\eta^{-1}(Lip\, h)^2$$
 
Cows
Cows
hmm
what are you solving for?
$G$ or $ \sigma$
 
0celo7
0celo7
$G$, but I will get an inequality
and I don't remember which way the inequality will go here
$\epsilon<2$
 
Anonymous
Are there imaginary terms in there?
 
0celo7
0celo7
9:14 PM
@Blue don't think so...
 
Anonymous
Okay. Then why not just write it in the $(x-a)(x-b)\leq 0$ form?
 
Anonymous
After that it's easy
 
Anonymous
You can find $a,b$ from the quadratic formula
 
0celo7
0celo7
well, maybe there are imaginary parts
it's hard to tell
 
Anonymous
Hmm, even then the quadratic formula will give you the roots. Then use De-Moivre's and analyze
 
0celo7
0celo7
9:24 PM
well yeah I have the roots but the descriminant is something horrible.
 
Anonymous
Ah, well. The inequality itself does look horrible :P
 
0celo7
0celo7
it took me like 6 hours to derive it
 
Anonymous
Maybe try replacing those symbols with A,B,C,D, etc and plug into mathematica or wolfram
 
Balarka Sen
Balarka Sen
Horribilis horribilis
 
0celo7
0celo7
so by making $\eta$ very small, I can make the $c$ term arbitrarily large and negative
so that forces the parabola below the axis
this is by no means an optimal estimate though...wonder if I care.
 
Anonymous
9:26 PM
Trying to graph it (by estimation) often provides valuable insight
 
Anonymous
Very useful for cubics, quadratics, and higher orders
 
0celo7
0celo7
I've been doing this for a while, I know what graphing does :p
li probably has a mistake, nothing unusual about that
 
Anonymous
I hope you can find someone interested enough to touch that horrible thingy and help :P I'll run!
 
Anonymous
 
Anonymous
Anyway, that's another great video by 3B1B
 
Anonymous
9:36 PM
Released today
 
Anonymous
I need to learn how to do those animations
 
0celo7
0celo7
9:48 PM
@Blue I overlooked the easy fact that because it faces upwards and has one point where it's nonpositive, the two roots must be real by the intermediate value theorem
 
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