« first day (2029 days earlier)      last day (2885 days later) » 

user54412
2:55 AM
@ZachSaucier I very much agree that answer isn't satisfactory, and doesn't really answer the question. On the other hand, I'm pretty sure there is no really satisfactory answer. I hate to fall back on the tired cliche, but at least in this case "physics does not answer why" is really the most appropriate response.
 
@ChrisWhite Why?
 
user54412
That said, there are many interesting and fascinating things that could be said about gravity, but it's hard to come up with questions for which they would be the answers.
 
user54412
@BernardMeurer ...
 
@ChrisWhite Jokes aside good evening :)
Well it's evening here at least
 
user54412
it is here too, whatever timezone that may be
 
2:58 AM
UTCW
Chris White Universal Time
 
user54412
@3075 This is just the opinion of a single internet stranger, but I highly suggest having a roommate for at least your first year. There's a whole slew of social things one learns by being stuck in close quarters with strangers.
 
user54412
Especially when thrust into an environment where nobody has any friends, it's important not to isolate yourself and miss golden opportunities for meeting people when everyone is feeling particularly social.
 
@ChrisWhite That's good advice, I was thinking about that recently. I know it wasn't directed at me, but still
 
user54412
I try to sprinkle a little good advice in my otherwise directionless ramblings in this room.
 
@ChrisWhite You gave me more programming help in this room than most people in my life as a whole, I wouldn't call your rambling directionless :p
@ACuriousMind Can I ask you to ask a question to ask a question?
 
user116211
3:12 AM
-1
Q: Homework guidance

Bobbye BissetteI don't know where else to place this comment because I think I deleted my earlier question. This afternoon I asked a question about whether or not it was feasible for a gust of wind to alter the course of a car in a 48 ft. flyover. The responses I received were very nasty. Posters were quic...

 
user116211
I'm wondering which jerk upvoted it ;/
 
You know what
I'm going to run linux on my calculator
 
user54412
I hope that really means you'll program an abacus with a lightweight distribution, and then write an even lighter distro inside that one entirely using calls to bc
 
user54412
@MAFIA36790 This might not be good for your blood pressure, but you'll notice that most questions on this site get a single upvote no matter how much they don't deserve it.
 
@ChrisWhite Nope, I'm getting Debian on this thing
I don't care
It'll work
 
4:13 AM
0
Q: Homework guidance

Bobbye BissetteI don't know where else to place this comment because I think I deleted my earlier question. This afternoon I asked a question about whether or not it was feasible for a gust of wind to alter the course of a car in a 48 ft. flyover. The responses I received were very nasty. Posters were quic...

 
 
1 hour later…
5:19 AM
@ChrisWhite Calls to bc?
 
@DanielSank bc is an arbitrary precision command line utility
 
o_O
 
@BernardMeurer That's silly.
@ChrisWhite Does high performance coding eventually just warp your brain?
 
@DanielSank That's why it's awesome :)
@DanielSank I'm about to achieve something amazing
 
5:41 AM
@BernardMeurer ?
 
@DanielSank You'll see, I just wanted to build the tension :p
 
6:30 AM
@DanielSank @ChrisWhite Debian on my Ti calculator :)
 
 
1 hour later…
7:39 AM
I fel pretty good when I read a paper of less than 10 years
I'm like yeah, cutting edge B)
 
user116211
0
Q: Integration by parts with Dirac Delta function

RandomGuyI am having some hard time trying to understand the following "heuristic" integral, involving integration by parts with the Dirac's Delta. We start with the following relation $$ f(x) = \int_{-\infty}^{\infty} f(a)\delta(x-a)\,\mathrm da $$ which is my starting point. I found in a book the follow...

 
user116211
So, isn't it better at Maths?
 
2:54 PM
ahh why am i so bad at cycle decomposition notation
$\sigma = (1~3~5)(2~4)$ $\tau = (1~5)(2~3)$ , $\sigma \circ \tau$ is $(1~3~5)(2~4)\circ (1~5)(2~3) = ?$ Is the correct way of doing this, to do the permutation on the right then permute the newly permuted elements at the location of the previous elements?
so like 5 is now at 1, 1 is now at 5, 2 and 3 are switched. Using these new locations for these elements, do the left permutation?
$(1~3~5)(2~4) \circ (1~5)(2~3) = (5~2~1)(3~4)$ is what I get doing this.
answer is $(2~5~3~4)$
 
3:25 PM
Greatest question ever:
-6
Q: Does Sun speaks Om?

Parth TrivediIn india on whatsapp people forwards a pic that shows that Nasa says Sun has a voice and it is ancient om. Is it true or just fake cheating idea of Indian people?

3
 
WOW @SirCumference that edit changes the question quite a lot. Going to bookmark that
"give me a chance to edit it" priceless..
 
user116211
3:42 PM
@SirCumference When did people begin to believe Whatsapp messages?
 
user116211
Damn
 
@mafia Not saying all religious people are unscientific (though most are), it doesn't surprise me that all of his rep is in a religious SE.
 
user116211
Just don't give a shit to go deep on this... forget that.... you'll always get a troll.
 
that looks really interesting @vzn I wonder what @acuriousmind 's thoughts are on that.
 
vzn
3:56 PM
@Obliv :)
 
user116211
@Obliv Even he is a troll in that religious site ;P
 
4:29 PM
@Obliv Just like with that funny bump in the LHc results, I think "Wait and see" is the only reasonable thought on that. Let other experiments confirm this anomaly/get a statistically robust result, and then go on to figure out what experiments to do to distinguish between the proposed explanations.
 
are there only 2 different $n$-cycles for every $S_n$?
 
user147690
@Obliv What do you mean?
 
user147690
What are the two you had in mind?
 
I ask because $S_3$ only has two $3$-cycles
 
user147690
Which are?
 
4:36 PM
$(1~3~2)$ and $(2~3~1)$
written in whatever order
 
user147690
And why are there no more?
 
because there is only two directions to cycle these numbers to form a new cycle
but they end up forming the same cycle
 
user147690
And what about in S4?
 
user147690
1234,1243,1324?
 
user147690
Draw the cycles as graphs, then change the labels
 
4:38 PM
and 1,4,2,3 and 1,4,3,2
are there any more than these
 
user147690
1 more
 
I see..
 
user147690
In math you should aim to find counterexamples, by considering simple cases
 
user147690
Also I would in general worry about seeing S3 has two 3-cycles and consider that there are 2 n-cycles in Sn
 
user147690
That would be an insanely strong claim
 
4:43 PM
I was influenced by there being only 2 reflections in $D_{2n}$ so I thought maybe that had something to do with it
 
user147690
2 reflections?
 
$s^2 = 1$
 
user147690
There is one reflection, it is it's own inverse
 
yeah thats what I meant
 
user147690
How did that influence you though?
 
user147690
4:45 PM
Do you know the Weyl group?
 
I looked at $(1~2~3)$ and $(3~2~1)$ as the only two orderings that can be represented by 1 cycle each and they are reflections of each other
no i dont
like $(1~2~3) = (2~3~1) = (3~1~2)$ and $(3~2~1) = (2~1~3) = (1~3~2)$
there exists only 1 unique cycle for each case and I thought every group $S_n$ could be 'flipped' in reverse order so that only 1 unique cycle exists for each reflection.
but I didn't consider that you can re-arrange all of the elements within the first and last elements
 
5:27 PM
Wait
I think I get it
Ghosts can go through wall, but
The reason they do not sink to the center of the earth, or fly off into space (if they are immune to gravity) is because they will follow mostly geodesic motion
Wait no
They should still sink
How do ghosts work
 
vzn
6:25 PM
@Slereah thx for your interest in the speaker series. are you serious about being available? did you +1 the meta ad? @Obliv what about you? ps Obliv plz star that nature article if you like it :)
 
Errr sure why not
I mean I already ramble all day long
It wouldn't change much
 
vzn
cool :) ... @DavidZ is Slerieah ok as the invited guest? DZ also was thinking you would be an excellent starting guest. think while there has been much valuable feedback, would like to get it going 1st time without a lot of overhead/ setup etc
@Slereah it would be a new level, assure you. could you update your SE profile with key info eg your phd thesis link, or was it masters? did you ever post it in here?
 
6:44 PM
I only have a master thesis :(
also it's in French
 
vzn
@Slereah no problem :) could you translate the title/ abstract (somewhere on web)?
 
sure
 
vzn
@Slereah thx :)
 
Hm
I don't think there is an abstract?
Basically it's about path integrals in non-relativistic quantum mechanics, how operator ordering works in it and an application to Riemannian spaces
 
vzn
@Slereah ok. wondering, do you have any physics papers in english?
 
6:53 PM
Nope
None that I ever finished, anyway
 
vzn
lol ok np
 
vzn is now wondering why he booked some random jerk for his big physics talk
 
vzn
@Slereah lol not sure who you are referring to :P
 
It is meee
 
vzn
@Slereah uh, just try to keep the 4 letter words & refs to blood going well on your cereal for outside the speaker session ok? :P
 
6:56 PM
Well it wouldn't be one on colloids, anyway
 
vzn
@Slereah maybe will have to introduce you by naming your favorite comedian (great taste on that btw)... :P
 
7:12 PM
Hello! What is this exactly?
 
A..."chat"
In this case, the main chat of Physics
 
No, I mean what is it for? Why, on StackExchan ge?
 
chatting n stuff
 
I am sorry but I don't understand why an entity having questions answered would like to have a chat.
 
7:15 PM
Is this done in order to reduce load upon comments?
 
nope. its just cause its fun
 
12
A: Real use of Chat?

Shadow WizardThe real answer is really, really simple. There is no real use for chat That's it. Once you grasp this fact, you understand the meaning of chat.

 
here we ask the important questions
those which cannot be asked in the main site
eg, @JohnRennie may I ask you whos the handsome gentleman from your profile picture?
 
I'm afraid that's me
 
7:18 PM
Oh well, I guess it's cool...
So, @AccidentalFourierTransform Did you draw your own profile picture?
 
@JohnRennie I totally didnt know ö
@AdamKarlson nope
 
For instance
Why do ghosts float
 
@AdamKarlson if you scan back through the chat room history you'll see that lots of physics is discussed here. Though there is much random nonsense discussed as well!
 
we can play a game
guess who I am
 
Ah.... So, it's SE on a party night?
 
7:20 PM
"blah blah manifold blah blah pokemon"
3
"yada yada einstein-de haas yada yada"
 
Is it @0celo7
Oh that's JD
 
2/2 cmon people youre not even trying
guess we know who won
 
Looking Glass Universe?
 
wot
 
I tried....
It's a YouTube channel... It bore resemblance to it.
 
7:24 PM
Any thoughts on 'intersection theory' in differential topology? Seems like it's like a coordinate-free generalization of the fact that you define a system of non-linear equations by the intersection of surfaces?
 
Dunno what that is
 
Hey... Can someone help answering a question?
 
Ask the question and see ...
 
-3
Q: Work done in less than a circle

Adam Karlson For a horizontal uniform circular motion, involving conservative centripetal force, (much like in case of satellite) Work done in a full circle is zero. But what about half circle or any other random displacement? Is it also zero? Is the work done zero due zero displacement (in a full circle) o...

For some reason it has so many downvotes!
 
7:33 PM
I'd guess the downvotes are because your question is unclear
 
By work energy theorem, shouldn't work done always be zero?
 
If the force acts at right angles to the motion then the work done is always zero
 
In a circumpolar satellite. The work done is zero going from North to North, but what is it from North to South Pole? Shouldn't it also be zero?
 
But in general if you move in a circular arc the force will not always be normal to the velocity so the work will not be zero
 
That's the question, does it always? I used an approximation of circular path as a straight line... And by keeping force constant along that, (and also perpendicular to it), it came out to be always zero
But if its not normal to velocity, won't speed change?
 
7:42 PM
You're considering the special case of a body in a circular orbit around a spherical mass. In that case the force is always radial and the velocity is always tangential so $\vec{F}\cdot\vec{v}$ is always zero.
But you don't make this clear in your question.
Suppose I consider a roller coaster that does a circular loop. The work done right round the loop is zero, but between the bottom and top of the loop the work is not zero.
 
@3075 physics app dropped
 
So this is an example where over a semicircle in a conservative field the work is non-zero
 
8:02 PM
@BernardMeurer what do you mean?
 
Apparently, hyperreals require ultrafilters to define a measure on $N$ so that the measure is 0 on finite sets and 1 on $N$
 
@3075 Dropped on quest that is, showed up
 
@BernardMeurer I thought you meant they dropped it, like declined.
you have bad word choice.
 
@3075 Not yet :v
 
@BernardMeurer what about compsci?
 
8:05 PM
@3075 Still on Deny and Brian haven't sent me anything, I'll just be pacient
 
k
did you call diana kim?
you should.
 
Wait
 
or did she reply to your email
 
They say the set of "big" subsets of $N$ is a filter
And they say that $\emptyset \in U$
But earlier they said that $m(\emptyset) = 0$
D:
WHICH ONE IS IT
 
@3075 No replies from her yet
 
8:07 PM
@BernardMeurer call
 
The empty set isn't even cofinite
 
@3075 519-888-4567, ext. 36243?
 
should be
idk
sounds right
 
Ah, apparently the trick for hyperreals is
You look at sequences in $R$ converging at different speeds
Apparently the ultrafilter is how you get those
 
@3075 Alrighty
 
8:10 PM
@Slereah why does the hyperreal extension of the interval $^*(0,1)$ contain infinitesimals?
 
And that is done by the equivalence relation that, if two series have a cofinite number of identical factors, they are the same
Well as I said
You can have two different series which go to, say, 0
Like $1/n$ and $1/n^2$
But in the hyperreals, those may be different numbers
Because the rate of convergence is also taken into account
Not just the limit
 
would $^*[0,1]$ be compact?
 
Depends on the topology you define on it, I suppose
 
can you explain
because $^*(0,1)$ is not compact
 
not a clue
I don't know how they define topologies in $^*\Bbb R$
 
8:18 PM
@Slereah it would be fun to formulate a non-standard model with non-standard analysis :D
 
Well I am reading a paper on this
It's kind of vague, though
 
the mass of the photon could be $\mathrm dm$
counterterms would be "finite"
 
Well the point of any physical theory that would use such thing is
The measurable parts are all in $R$
 
@BernardMeurer did you call? D:
i'm curious what they will say because I also called them once and they were helpful.
 
@Slereah oh but if numbers depend on the rate of convergence, different renormalisation schemes would yield different results O.o
 
8:23 PM
Not really, no
 
(did you already notice that I have no idea about all this?)
 
The point of constructing the field is that the details of its construction don't really matter once it's done
 
@3075 Done, Diana is super cool
 
You use real numbers without worrying about Dedekind cuts
 
you dont know me!
;-)
 
8:27 PM
@3075 She said she'll double check and get in touch if there's anything wrong
 
Some random ramblings about string theory about to happen here :P
So AFAIK you literally write down the Lagrangian for a real string and then play with it, then things happen?
(bare with me, I am not trying to be specific)
 
the brane of my heterotic duality is a symmetry of the central vacuum in a holographic setting of tachyonic casimirs, whenever you have a supersymmetric extra compactification. Black hole.
 
What duality are you invoking there T S ?
 
I see
 
8:34 PM
science.
 
@kevinTahN. You don't "play" with it, you quantize it.
 
definitely, we quantize it
So the main characters at the beginning are the Nambu and Polyakov actions
?
 
The only relevance of the NG action is that it's the "natural" one to wrote down. All the string theory is done from Polyakov.
 
yes, indeed
 
@bernardM hey how hard do you think it would be to program a calculator that displayed the prime factorization of the solution each time?
 
8:41 PM
@ACuriousMind I've been meaning to ask you about what people who study statistical field theory actually do, I saw the table of contents of a book on the subject once and it had every thing from stat mech, qft, cft, ads/cft and even numerical methods in there. It looked quite sexy! but alas what is statistical field theory anyways?
 
@kevinTahN. And...what gave you the idea that I have any idea about statistical field theory? oO
 
@ACuriousMind well, you know quite a lot :D
plus there is still a jury out as to if you are secretly an advanced extraterrestrial AI
 
Well, all I could say about "statistical field theory" is that I think it's "just" QFT in Euclidean space :P
 
@BernardMeurer <3
 
that makes sense, I was leaning in that direction :)
 
8:48 PM
@DanielSank <3
@Obliv prime factorization is an NP problem, so programming it isn't hard but if the result is large it'll take a while to get prime factorization
 
9:16 PM
Can I write a math paper
It will be called "Let's just say that we admit the continuum hypothesis into ZFC"
"Like geez"
Get a clue guys
 
I might be posting this again, but in case anyone missed out on its brilliance,
-7
Q: Does Sun speaks Om?

Parth TrivediIn india on whatsapp people forwards a pic that shows that Nasa says Sun has a voice and it is ancient om. Is it true or just fake cheating idea of Indian people?

 
vzn
9:39 PM
@Slereah (forgot to ask) can you do a session at the std biweekly time? or do you have some other time preference? also if you would like some kind of intro in particular, plz let me know, otherwise will try to piece it together
 
@AccidentalFourierTransform me
@AccidentalFourierTransform the goblin
 
vzn
wondering what the difference is between an accidental vs intentional FFT
 
Yeah, no thanks google
 
...why did the first picture you posted have "space" instead of "good" in its heading?
 
because the original is this
But my Mac computer won't show that. So I just photoshopped the first one I sent ya to give you the idea
 
9:55 PM
...what?
 
@vzn it's not my job to determine the guest!
;-)
 
vzn
10:17 PM
@DavidZ np. was assuming (with that question) you have veto power. but seem to have no objections to anyone mentioned (so far) even potentially controversial speaker(s) eg Motl. thx for being so flexible. :)
 
@SirCumference you're bad at photoshop.
 
Jesus christ, stop slandering me
 
also if I search that with "how much does a space telescope cost" I get that image, but if I search what you did I don't.
did it with 3 different browsers and 5 different ips and same result.
what that implies is that maybe it did display that a few years ago, but your image is fake.
:/
 
10:36 PM
Server is down, right?(for main site)
 
@ramsay Doesn't look like it here
 
" Why are you not sharing String Theory's equations? Why do you refuse to do this? "
 
It's not fake. My image is from two months ago
 
They are mine, I will never give them up!
 
It's still here
Hell, if you don't believe me, look at the date here: reddit.com/r/funny/comments/4c12i4/ok_thanks_google
 
10:38 PM
I'm having deja-vu (fuck those accents). Didn't you two have a very similar fight about shopped images a while back?
 
IK
This guy's still harassing me
 
dafuq?
 
Oh for fucks sake no one is harassing anyone :v
 
@ACuriousMind We oughta stop deleting bad posts
A lot of them are hilarious and need to stay
 
My neighbor's weed smell is flying through my window and I'm getting pissed
 
10:41 PM
@SirCumference No, they need to go. This site is not here to have hilariously bad posts on it.
 
@SirCumference because pse is for fun and laughter?
 
A laugh or two couldn't hurt
Not that we should encourage those questions...
But still, closing is enough
 
@BernardMeurer I thought "getting pissed" meant getting drunk, not high...
 
@BernardMeurer Close your window?
 
@ACuriousMind I'm neither! I'm getting angry!
 
10:42 PM
Why?
Oh, of course, you're angry because you're not high.
 
@ACuriousMind 'Cause he doesn't want to smell weed?
 
@SirCumference you encouraged them right now.
 
@SirCumference This is one of the only days in my life in Brazil where it's under 20ºC I'm not closing my window
@ACuriousMind I don't like the smell of weed
 
@3075 Still. If we deleted them all we'd be missing out on questions like this
-7
Q: Does Sun speaks Om?

Parth TrivediIn india on whatsapp people forwards a pic that shows that Nasa says Sun has a voice and it is ancient om. Is it true or just fake cheating idea of Indian people?

 
@BernardMeurer I already inferred that ;P
 
10:44 PM
Ya can't tell me this isn't gold
 
It ruins the quality of the site.
 
Then we close them?
 
@SirCumference It isn't gold.
 
@ACuriousMind You Germans are all junkies :p
 
10:45 PM
@BernardMeurer ...and how did you conclude that? :D
 
@ACuriousMind Ya can't be too serious all the time
 
@BernardMeurer would you believe me if I said i don't know how it smells?
 
There's annoying bad and there's funny bad
 
@ACuriousMind Every German I know smokes weed
 
@3075 Nor do I.
 
10:46 PM
but then also every German I know is in the green party
@3075 I would, it's not that bad, it's just a weird smell
 
...how many Germans do you know?
 
@knzhou Howdy
 
hey!
 
@ACuriousMind Some 10, why?
 
I believe the thing about the weed, but not about the Green party :P
 
10:48 PM
I know a lot about green party peeps hahaha
 
@knzhou We're talking about Bernard and his weed addiction
 
o.0
 
@SirCumference ...liar.
 
@SirCumference Hey!
 
I'm kidding
._.
 
10:49 PM
did you learn calc 3?
 
@3075 me?
 
Nah, just starting Calc 2
brb
 
that's a shame.
 
Ya know, maybe you guys are right...
 
@SirCumference Look at the score lol
 
10:51 PM
Wtf
 
I still prefer that one about the wolf
 
You guys haven't seen the truly WTF posts
 
-9
Q: The Moon And Warewolfs?

Zacharie TowersAs we all know ware wolfs are the creatures that no one is sure exist's but i have a theory that has some controversy that could help,considering the fact that the moon and sun help control the ocean waves,plasma in a human's blood is made of 91.5% of water,also as we know some people react diffe...

 
@ACuriousMind you didn't ever show us the weird question about the forming a female from physics.
:'(
 
10:54 PM
Goddammit man!
Why!
 
@SirCumference rigid-body-dynamics
 
@3075 Get 10k rep and you can see it, the link is somewhere in the chat transcript ;)
 
Why did you delete that?
It was gold...
 
@ACuriousMind ss please.
 
@ACuriousMind You're evil...
 
10:55 PM
@ACuriousMind I will someday.
 
@SirCumference I prefer the term "morally flexible"
4
 
I asked but I didn't receive.
I demand a refund please.
 
Ya gotta allow some joking
 
@ACuriousMind :'''(
 
Everyone needs a laugh once in a while
 
10:58 PM
@SirCumference I agree with you for once.
 
Deleting 5 month old questions doesn't help anyone
 
@vzn nah, I'm not claiming veto power. This is a community-organized event. You could in principle do it entirely without my approval, or without getting any of the moderators involved at all. Our (mods') role in this is simply to help you out with advertising. We're being a resource, not being in charge. That's how it should be.
 
yesterday, by ACuriousMind
One of my favorites
 
vzn
@DavidZ ok. cool. aka lassaiz faire... would you consider being the speaker sometime? any conditions on that? not 1st time? etc?
 
hellloooo
anyone there? :/
 
11:27 PM
@vzn did you look at that document?
 
@vzn I won't rule it out, but if it's going to happen, probably not any time soon
 
@usukidoll seems you are new here?
 
vzn
11:39 PM
@DanielSank yes, thx for effort, think its fine, maybe run it by EP if possible who had that main objection about lack of clarity/ purpose? also do urge you to go ahead & try out/ use meta as proposed, although (as recent experience attests) think sometimes it feels like a "shooting gallery" :(
 
@DanielSank <3
 
11:51 PM
I'm rarely on this chat
 

« first day (2029 days earlier)      last day (2885 days later) »