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16:00
@Secret Are you guys ready for a huge nuclear war? I mean, if tomorrow a worldwide nuclear war happens, what are you gonna do to survive, as scientists?
I'm looking for some thoughtful advice to stay safe
Wrong person to ask that question. I am eager for all of us to simultaneously die, be alive and nothing happened
This music describe it really well:
@Mostafa Duck and cover!
An eternally unchanging, calm, still, stagnant, hopeless, .... (omitted countable number of words)
... that nobody and no metaphysical entity can dreamt of escaping
Where all concepts are meaningless, because they blend and fuse into one. There is no distinction between reality, fiction, fanon, canon, surreal, superntural, (omitted countable number of words) ...
@Mostafa Selling herbal potassium iodide
@ACuriousMind: are you (a) around and (b) interruptible?
16:14
everyone is interruptible
it's easier when they're around, of course
@JohnRennie Aye and aye
@ACuriousMind that space probe/laser problem ...
I was having a quick play with it and found what seems to be a simple way to describe the motion.
This is your chance to express your deep and committed lack of interest in the problem :-)
16:30
@JohnRennie Nah, I'd be curious if there's a nicer way than that ugly differential equation
Well start with $E^2 = p^2c^2 = m^2c^4$ and differentiate wrt time to get $$2E\frac{dE}{dt} = 2pc^2\frac{dp}{dt}$$
And rearrange to get: $$ \frac{dp}{dt} = \frac{E}{pc^2}\frac{dE}{dt} $$
$E=\gamma mc^2$ and $p=\gamma mv$ so that simplifies to: $$ \frac{dp}{dt} = \frac{1}{v}\frac{dE}{dt} $$
And $dE/dt$ is just the rate that the probe is absorbing energy from the laser, which is $(1-v/c)P_0$ with $P_0$ the constant laser power.
Oh wait ...
Rats ...
Not all of the absorbed light will be going into kinetic energy ...
OK, carry on, nothing to see here.
> Are you scientists happy with your life and your job?
16:42
@AccidentalFourierTransform I just saw that too :-)
@MelanieShebel Hi
Hello @Melanie
@AccidentalFourierTransform ::faint sobbing:: ;P
@AccidentalFourierTransform Me? Yes, a career in physics (sort of) has been very good to me.
16:43
I went to a session where the chemist behind "Breaking Bad," was talking about her work on the set. she said the first day she got there, they asked, "What do scientists do... for fun?"
"How do they act?"
@JohnRennie Yeah, I think that your approach comes down to pretty much what it did, once you do the chain rule on the $p$ it becomes just as ugly
That question just reminded me of that session, haha.
@JohnRennie yes, you told us about those large cheques ;-)
@JohnRennie Call your soap science what it really is ;)
@MelanieShebel while I'd hesitate to describe any of the ruffians and scoundrels that hang out here as normal, I suspect we do much the same as normal people do for entertainment :-)
16:46
Hey!
We just do it with a lisp.
jk
I'm normal.
The normalest.
@MelanieShebel Like (have fun me)?
@MelanieShebel edits are over on chemistry.se ? You are here..
16:48
@AccidentalFourierTransform the joke never gets old :-)
@AccidentalFourierTransform why did you delete it?
I don't get it. :'( Just a chemistry undergrad that realized she likes physics more. :'(
@AccidentalFourierTransform Didn't we talk about these images? Don't use 'handicapped' or 'retarded' as an insult.
@MelanieShebel I'm a chemistry graduate as well. I did my PhD on solid state photochemistry then wandered into colloid science. The great thing about physical chemistry is that you can choose as much or as little physics as you want to do.
@JohnRennie I saw something -+++ , can you explain what's joke ins it?
I just don't want to stir things. I got tricked into thinking a chemistry major would help me focus on whatever was in chapter 7 of my chemistry book.
Which happened be photons, electrons, light, particles, and waves.
Correction: particles and/or waves.
16:53
@MelanieShebel I don't think I did any wet chemistry in the three years of my PhD. The closest was making up solutions to clean my vacuum kit. Chemistry is a vast subject and there's bound to be something that interests you towards the more physics end of it.
Yup, @Fawad, I am here. Don't worry, I won't flood the page with edits.
Just FYI: You can edit chat messages for two minutes after they're posted - press the up arrow key to do so or click on the left side of the message and choose 'edit'
How can I create a space that its fundamental group is isomorphic to S_3? (without wedging circles, maybe by quotient)
@MelanieShebel I specialised in quantum chemistry in my final year then went on to do photochemistry, which is all photons, electrons, light, particles, and waves!
That sounds like a blast.
16:55
@MelanieShebel That's the point. There is loads of scope in chemistry to do what is basically physics. The two subjects overlap a lot.
@ACuriousMind you free to help others. You know what's joke in -+++?
Yeah! I used to get, "This question belongs on Physics.SE," a lot!
Chemistry is molecular physics
@Fawad There are two equivalent metric signatures in use, -+++ and +---. Each form has its dedicated followers who think using th other form is stupid.
16:57
Haha
In chemistry, there are many subfields that involve photons and quantum stuff.

If you are working with photovotalics, then things like triplet fission and excited states are common things.

In atmospheric chemsitry, photochemical reactions are complex to model and just any one molecule alone is already a honours or PhD project

Photocatalysis is also a huge topic, and DFT modelling of metal complexes that can take many electronic and spin states are common things

Any domain in computational chemistry necessary involve solving multiple electron schroedinger equations, though the really qua
@JohnRennie thanks. I thought people put me on ignore..
The sadly deceased (temporarily) @AccidentalFourierTransform was making a joke that saying the correct signature is -+++ means you're a fool.
As a rule people who study quantum field theory use +--- and people who study general relativity use -+++. Naturally each think the other is using the wrong signature.
@mathvc_ Wedging circles is in general the best way to construct first-level Eilenberg-MacLane spaces, although there are more abstract constructions. Why don't you want to wedge circles? (Also, you might consider asking in the math chat instead, there's a (slightly :P) higher chance to find topologists there, I think)
@JohnRennie that's funny.
17:02
All the above subfields I have listed have both industrial and fundamental reserch ties. For example, artificial photosynthesis is an emergent thing
@Fawad Physicists don't really argue about the metric signature because the different forms have advantages in different circumstances and everyone understands that. However it has become a meme that people joke about.
How do LHC work?
@RishiKakkar that's an awfully broad question. Was there some specific aspect of the LHC that interests you?
yes the collision process
@RishiKakkar that turns out to be remarkably complicated. At LHC energies particles are described as the states of quantum fields. So the collision is really the interaction between quantum fields.
17:07
Can you please explain this
@RishiKakkar have a read through:
48
A: What keeps mass from turning into energy?

John RennieThis is inevitably going to be an unsatisfactory answer because your question is vastly more complicated than you (probably) realise. I'll attempt an answer in general terms, but you have to appreciate this is a pale shadow of the physics that describes this area. Anyhow, Einstein was the first ...

Some days ago when I sat through one of my friend's QFT lecture that talks about scattering of electrons and positrons, the fact that none of the individual feymann diagrams is the real process but that their sum is sounds awfully similar to how we deal with resonance contributors in delocalised systems in chemistry
except (pardon if my level is still insufficient to make correct remarks) for chemistry, we can do away with the resonance contributors completely and work with the wavefunction or (for most cases) the probability density (as in DFT methods), but we cannot do the same for interacting quanutm fields since that variation equation is extremely hard to solve directly
can antiparticles do the same collision according to QFT
@RishiKakkar Particles and antiparticles are basically the same thing. See for example this question of mine.
17:20
mean, mean people over here
And a general question?
QFT requires that both particles and antiparticles exist, though it is possible for a particle to be its own antiparticle (e.g. a photon). So QFT describes antiparticles in the same way it describes particles.
what are the rare cases for an electron "the rare and unusual positrons"?
Well not exactly
They have different ladder operators
A particle state isn't the same as an antiparticle state
(unless the field is real, of course)
@RishiKakkar for some reason that we don't understand there is far more matter than antimatter in the universe. So electrons are common but positrons are rare.
Trying to find out why there is this difference between matter and antimatter is one of the big unsolved problems in high energy physics.
17:25
What are the cases that an electron converts to positron?
the cases are not.
@AccidentalFourierTransform I thought your punishment was a bit harsh. Your post made me laugh.
but as the physicists say there are more matter then antimatter
@RishiKakkar ??? there is more matter than antimatter not the other way around.
17:26
@RishiKakkar Huh? That's certainly not the case.
Explain
@RishiKakkar explain what? There is obviously more matter than antimatter because everything you see around you is made from matter.
@JohnRennie and space? It's huge..
@Rishi Positrons are rare, but they are not that rare. We can use ${\beta}^{+}$ decay to produce plenty of positrons.
17:31
What is annihilation?having a hard time to understand this
when you have and then you dont
$$\Huge{e^{\chi}P(\Lambda \alpha I \mathcal{N})}$$
Uh, that renders really badly
@RishiKakkar In QFT the quantum fields can exchange energy with each other. That means in an interaction some particles disappear and other new particles appear. This is how new particles like the Higgs boson appear in collisions at the LHC.
For a particle and antiparticle the energy can be transferred into two photons, so the original particles disappear and the two new particles (the photons) appear.
It is just another scattering process, but one that doesn't require a high collision energy and proceeds with a very high probabilitiy.
Decades of science fiction books have left people with the idea that annihilation is somehow weird and mysterious, but it is just another type of QFT scattering and is described (to great accuracy) by QFT calculations.
ugh, I have three emails that I have to send, and I've been putting them off all afternoon
should I do it now? or should I do the dishes?
If someone wants to study high energy physics is that a good topic?
17:41
@AccidentalFourierTransform depends on which is more urgent
@RishiKakkar no
@Secret the emails, clearly
but I think im gonna go with the dishes
Just throw them out the window and buy new ones
You're poor or what
very poor, yes
actually, do the dish
I only have one
sup with the stars peeps?
Hello people! What do we talk about here?
@RishiKakkar it's impossible to tell what you'll enjoy as a researcher. I ended up working in a field that i didn't even know existed when I was at school.
17:44
@user41508 communism and slaughterings of animals
@user41508 Whatever we want to talk about - you are currently witnessing a rare time where there's actually physics going on ;)
i am like mad about the particles i find them intriguing but my father never allows me to touch the books of the nuclear physics and quantum field.
haha, ok, a casual chat. Nice to meet all of you
causal casual chat
ah, good old sacrilegious nuclear physics books
Well, you should read the books, not fondle them!
17:46
you know, you can always hide QFT texts inside Playboy magazines
that'd be easier to explain than the other way round? :P
that's a great idea @AccidentalFourierTransform
you heard it here first
::looks at Ocelot cuddling with a Spivak book::
What is dark matter ? like space is filled with it
17:49
why will your father not allow you to touch his nuclear and quantum books?
you are not gonna make a nuclear bomb from just reading that, right?
A guy after reading science fiction"We can open a worm hole here "
A guy after reading a Playboy magazine "we can..." actually, nevermind
@Secret I am just a kid of 16 what he did say is" i don't expect you to do phd in the branch of nuclear physics just read your course books"
And you're too curious?
17:52
There's a urban legend along the lines where a math grad student hid his "magazine" when his advisor came in and when he pulled it out - with a serious face - of the not-so-well hidden place, looked, and commented, relieved: "Oh! I thought it was Bourbaki."
5
(The urban legend is almost certainly a fact, but maybe I shouldn't spell the names involved out loud)
That's typical, but QFT is really high level stuff, you cannot expect to start reading it before you adequately study quantum mechanics, representation theory, functional analysis, linear algebra (and did I miss anything else important, guys ?)
Even if you are interested in it, you cannot just hop right into it and expect you understand it quickly
Electromagnetic theory and relativity
i know linear algebra differentials ,electromagnetic
relativity includes in book and the others too
@BalarkaSen I don't think any Bourbaki edition has ladies on the cover
You know Maxwell's equations in 4-vector notation?
17:56
Still hasn't taught
I'm guessing you know Gauss' law, Ampere's law and the like?
yea more kind of like that stuff
yeah, typical high school physics work
18:28
I already sent 2/3 mails :D
user228700
user228700
Wohoo!
user228700
Haven't you ever watched The Big Bang Theory?
what? I was just singing Rihanna
user228700
18:31
-_- Nice.
@Slereah The advisor clearly had a thing against Bourbaki
big bang theory is so boring
@user41508 TV in general is boring.
bourbaki is fine
18:35
exactly
it's the only math book that doesn't need any reference
well that and Russell
user228700
@user41508 It helps to kill time on lazy Sunday afternoons for sure.
there's a lot of better things to do on a lazy sunday. pondering your existence is one
user228700
> pondering your existence is one
user228700
18:39
certainly not on a lazy Sunday afternoon, for God's sake! That's when the existential crises tend to hit.
what do you mean? existential crisis is great
lazy sunday afternoons are for sleep ;)
user228700
@BalarkaSen Nope, my brain handles them quite...destructively so no no no, thanks.
read Dostoyevskii to get better ideas at handling them
user228700
18:41
@BalarkaSen Please recommend something and I will make sure that I add it to the top of my "to-read" list for the summer.
@user41508 Never sleep in the afternoons
spoiler: in "Crime and Punishment", the main character murders people to see if he can become Napoleon
why so?
@Kaumudi My own personal religious textbook of existentialism is Notes from The Underground.
user228700
18:43
OK. I will certainly read it, then.
here is mine
It's shorter compared to his other novels, hence more reasonable to read, too. Brothers Karamazov runs for two big tomes of volumes.
I should change my name and put up a pic..
Malazan Book of the Fallen
user228700
18:44
@JaimeGallego HOW DARE YOU?! :'-(
was that a rick roll
(i didn't click wink wink)
user228700
@BalarkaSen Yes, it was :'-(
lol get ricked
good thing I am choosy about what I watch in YouTube
user228700
18:47
It's quite hilarious x'D
I planned it beforehand >:)
"choosy", "Bowie", tsk tsk
@user41508 please do
I didn't see that, nope. I had to look up his tweet that's being meme-d.
I lol'd.
@AccidentalFourierTransform come at me bro
user228700
I mean, look at this: (x'D)
user228700
18:52
whos shashi tharoor?
an Indian politician
and why is buzzfeed suggesting the article "according to science, there are four types of penises"
user228700
@AccidentalFourierTransform I REFUSE TO ANSWER A GOOGLE-ABLE QUESTION!
i dont have a google
what about yahoo
18:54
yeah, I have three of those
user228700
Bing also works.
Best comment ever, by @AccidentalFourierTransform
0
A: Will a helicopter hovering 24hs in the air came back to its initial position?

Brad SNo. The helicopter will not move with respect to the ground if it is hovering. It will remain in the same spot. It is moving WITH the rotation of the earth and earth's atmosphere.

ah yeah, I'm a bit of a troll
can't help it :-P
user228700
@Balarka: Looked you up on Twitter. Is this you?
19:04
I do not exist on twitter
(lol that guy tho)
user228700
Is that a trick statement?
Nope.
I do not exist on any social networking site whatsoever.
user228700
His name is the same as yours and he's even from Calcutta!
I would call chatting social.
And kind of networking. :P
there's a couple guys with my name out there.
19:05
what!? 25k followers?
Who, me?
Yeah, I like Twitter.
user228700
In any case, @Balarka: It's a relief that you're not the same as that guy.
user228700
...his "Following" list on Twitter is a bit, erm.
19:06
hence the lol
what.. I mean how...
what do you do on twitter?
i mean, 25k is a lot
chatting is social to some extent, but can be made in a socially unconventional manner, which i strive to do
Tweet, make jokes. Try to get people to read my chemistry jokes article.
an avant garde as i am
user228700
@BalarkaSen And you succeed to some extent! x'D
19:08
bows
I used to work in marketing so I'm really talkative online. I accidentally fell into chemistry/physics.
It helps pay my tuition.
so, I should follow you or not?
hmm who else is on twitter here
is @dmckee on twitter? should I follow him?
would @Slereah be an interesting user to follow? how about @ACuriousMind?
(no love for 0celouvskyopoulo7)
@AccidentalFourierTransform I'm not on twitter
oh well
I dont remember my password so its fine
@AccidentalFourierTransform No.
I do relatively little social media stuff.
19:13
yeah meh society
twitter is love, twitter is life
I was looking at @Kaumudi.H's twitter and I found this
user228700
:-P
and I swear I first read "boobs" instead of "books"
and I was like "well, yeah"
user228700
x'D Geez.
user228700
I guess I'm pretty easy to find on Twitter.
19:16
Guys, why can we still use the Gaussian cylinder for Gauss' law when $L$ is finite and $r\ll L$? Because in this case you don’t “feel” an equal amount of field lines from above as from below, if you’re not close to the center of the line. So things don't cancel in the same way they do for the hypothetical infinite line.
a twitter used to visit my window pane every morning
i brutally murdered it.
- gripping 2 line short story, titled "Why I Dislike Twitter"
omgoodness where are the experts:l
Sure, go ahead and follow
i hate that i love physics, for real
i'll post it on the main forum, so never mind
@ShaVuklia The approximation breaks down both for $r$ not much smaller than $L$ and being too off-center from the line.
19:23
ahh, right
also, you can always use Gauss law, because it always holds
its just that sometimes, its useless
Useless in the sense that we can't evaluate it analytically?
@AccidentalFourierTransform Thank you for this insight into your mind :P
@BalarkaSen Sounds more like "Why Twitter Dislikes Me"
I like that!
can I post a Looney Tunes youtube video?
19:28
You can post anything, you just have to bear the consequences :P
I mean, its a Looney Tunes video
you know, its for kids
there are still consequences
The consequences might be laughter.
0
Q: Problem in viewing MathJax formatted writing in smartphone

Wrichik BasuI access this site using Chrome from myou smartphone. Recently, the MathJax formatted writings appear overlapped, for example in the following answer: What could be the reason for this?

19:31
@AccidentalFourierTransform Now, I mean, it's pretty tame but why did you feel the overwhelming need to post that?
youtube suggested it to me, I posted it here
thats kinda my usual mental process anyway
find something stupid online, come and post it here
remember that I dont know my twitter password
@ACuriousMind Speedy Gonzales got sued for bearing Mexican stereotypes I think
so... nah
You behave too *logical*; always asking people why....
Typical German I guess ;)
No, typical theorist.
No, other theorists here aren't that way. Only Germans
19:36
@BalarkaSen I said might. If porky the pig had spewed some racist screed the consequences would have been that we wouldn't have seen AFT for a while :P
not many theoretical theorists here. everyone seems to be either a physicists, chemist, engineer, worm-hole fanatic, ...
I am the only mathematical mathematician ($\neq$ mathematician), which is close but no cigar.
@Mostafa I like to understand people :P
AFT is a pure abstract mathematical theorist.
@ACuriousMind Me too, man, me too.
My mental model of @AccidentalFourierTransform after his response is now an incarnation of the YouTube suggestion algorithm trapped in a human body.
Or a cat body, come to think of it
19:40
brutally fourier transformed
I would probably be a better algorithm than the one responsible for the HQL
@ACuriousMind a very beautiful human body
Im so proud of myself, I already sent the three mails that I had to send today
and to think that it only took me all afternoon!
BTW @ACuriousMind I found the Scholarpedia article in arxiv.org, so I can now plagiarise it as long as I cite it!
all's well that ends well
@AccidentalFourierTransform You have no idea what I find beautiful :P
@ACuriousMind Knorkator, for example.
I have a non-orientable manifold locally isomorphic to a torus somewhere in my body, I bet you'd like to see it
You don't know my life!
:P
19:47
@Mostafa Okay, you have a sliver of an idea ;)
@AccidentalFourierTransform Ew, gross.
well, it is asymptotically free, so yes, its kinda Gross
20:18
Hi, everybody.
Octopuses edit their genetic material at runtime.
@DavidZ Hello
@DavidZ If mods of 2 SE sites would agree that they mutually understand their site topics, could it make easier to have mutually migration pathes between these sites?
@DavidZ I think, maybe a migration path to the chemistry SE, engineering SE, aviation SE, space SE, astronomy SE and to the worldbuilding SE could be quite useful.
oh wait I misunderstood you
:37285779 Yes, but they don't have to understand the site topic of the possible community migratable sites.
@AccidentalFourierTransform I am thinking on some like a "mutual migration agreement" or similar.
20:25
Before anyone says anything else about this, I'd like to remind everyone to please prefer improving crappy questions over migrating them.
@peterh Useful for what? The volume of questions currently migrated to these sites per month is in the lower single-digits, well within what can be handled by moderators.
@AccidentalFourierTransform It could mean some similar: 1) community wiki meta posts on both sites, about when to vote to migrate to site X 2) mods create migration pathes on both sites to the other 3) if there are migration rejections, they wouldn't create also problems, there would be a communication channel to handle it (and, to tune the relevant meta wiki post)
@ACuriousMind If a question is enough good to be migrated (not LQ, clear, etc), but offtopic, would it be really migrated?
@peterh Uh, yeah.
wtf
@peterh Sure, why would you think not? The only reason I would reject a migration flag is for the old "Don't migrate crap." reason.
Hi, @ACuriousMind. How's life?
I hear Breath of the Wild is good.
20:32
@ACuriousMind Ok, thanks. I will watch. :-) A lot of question is closed as engineering. But the engineering SE is a beta site, and there is also a rule that betas don't get migrated posts.
Also recently played a fan remake of Metroid 2. It's amazing and I recommend it highly.
@ACuriousMind But, I think mods still can migrate posts to betas.
It's called AM2R.
@DanielSank It's...lifey
One of the better games I've palyed, to be honest.
20:33
@DanielSank According to my flatmate, it indeed is (I don't have a switch myself)
@ACuriousMind Furthermore, the close reason about engineering still doesn't even contain a link to the engineering SE.
@ACuriousMind What happens if you use your flatmate's?
@peterh That's because our notion of "off-topic as engineering" does not equal Engineering's notion of what engineering is.
@DanielSank Then we play Mario Kart :D
@ACuriousMind Which is a rather annoying problem.
@ACuriousMind Hmph. Mario Kart 64 was the pinnacle of Mario Kart.
@ACuriousMind Comparing this to this I think the first is a subset of the second.
20:40
@DanielSank That was good, too. Not going to start a MK edition war here :)
@ACuriousMind Very well.
@BalarkaSen I think, it is because we are all theoretical theorists. :-)
rob
rob
Just a matter of time until there's a YouTube video about me!
"guyWhomadethatVideo" ah, perfect
21:03
@dasharez0ne, YOUR ASS
https://t.co/sF9ATLXMh2
1.4k tweets, 61.6k followers, following 8 users
Here is a twitter to follow
21:32
Is there a good book on renormalization
21:58
@DanielSank 1k to go ::grin::

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