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user228700
12:00 PM
Anyway, I'm off. Bye :-)
 
Cya.
 
Bye
 
@skillpatrol subject tests
just maxing out on everything I can :P
 
I see.
Maxing out leads to burning out.
 
I have 4 years before I join a graduate school
I tried the Chem sample paper
It appears like IITJEE syllabus
hitting two birds with one stone
 
12:08 PM
IIT JEE is for undergrad admissions, right?
 
yes
but everybody gets taught UG math, physics, chem in coaching institutions
so that we can cheat in the exam
 
@YashasSamaga Here (Iran) we have a similar test for university entrance. It is a 4.5 hours long multiple choice test in Math, Physics, Chemistry, Literature and English.
I scored very well (top 0.01%) and made it to one of the best programs, but hate it more than anything else in my 16 years of education so far
 
aw
Here the IITJEE training institutions blow the syllabus out of proportions
If the test tests for 1 + 1, the institutions will teach you how to multiply numbers
 
such tests are at least 50% techniques rather than knowledge
 
yes
it is all about techniques
The problem is you get 90 questions, 180 minutes.
so you have to be fast
the training institutions teach way outside the syllabus so that we can hack the problem
 
12:17 PM
Exact same thing here. I still believe I've never recovered from that 6 months of studying for that test.
 
6 months?
Students are trained for 4 years here
12th grade gets over in 8th grade
and we start UG math, physics, chem from 8th grade
as a matter of fact, one out of every 5 students in India score 800 in SAT Math
let me show u the percentiles
88th
Your National Percentile
for 800/800 in Physics
90th
Your National Percentile
800/800 chemistry
80th
Your National Percentile
800/800 in math level 2
it feels like solving 9th grade questions in 12th grade
 
Here also 90% of students start from the beginning of high school. But I didn't. I was studying for the Physics olympiad at that time.
I completely feel what you're saying....and I really hate it. I consider myself a victim of such system.
 
The U.S. standard is too low.
The so called "advanced" placement tests which are conducted in U.S. are our high school 12th grade syllabus
high school syllabus != IITJEE syllabus
 
I remember a research institute in India consisting of high school students doing research in String theory and high energy physics but can't find it now
 
TIFR?
Though there is one problem with India's education system, nobody knows what they are taught properly.
 
12:27 PM
Who care's who's education system is better
success isn't measured by your education but by your achievements
education itself isn't an achievement, it is a means to an end
 
@YashasSamaga I visited TIFR website it doesn't have any high school kids doing research in HEP
 
CMI is having high school students doing research in math
IISc has graduate students who are just 20 years old
 
I'm trying to find it
We had one similar user here a few years back
Dimension10
but I can't find him now neither
 
@Kenshin And who cares about your "success" if you're feeling miserable? Hearing about all this testing and training and competition students are apparently subjected to worries me deeply.
@Mostafa He has changed his username here and now primarily participates at PhysicsOverflow (or did, I don't know about PO's current status)
 
@ACuriousMind yes that's my point. Having a very competitive yet thorough education system isn't necessarily a good thing. More focus is on "education" than actually getting good things done for society
 
12:40 PM
I do not believe that being drilled to succeed in tests is what is usually meant by a "focus on education" :P
 
@ACuriousMind well yes but that is semantics, I think we are in agreement in principle
 
@ACuriousMind That's exactly what I'm saying. You should be thankful that didn't experience such a system.
 
Well, students are not forced into it.
Majority of the students go through the normal schooling here (India).
 
What is "normal schooling"?
 
you study 12th grade in 12th grade
in the other highly competitive schooling, you finish off 12th grade in 8th and start UG
 
12:47 PM
What about university entrance?
 
Some take in 11th grade, some in 12th grade
There are students with MSc who are just 16 years old.
The record holder is a 15 year old girl atm.
 
I couldn't find that website but could find Dimension10. He had difficulties explaining some concepts in electrostatics yet he participated in discussions on string theory (which I couldn't understand).
 
To be fair I know GR but I barely remember thermodynamics
 
@ACuriousMind sounds like you're new to India
@ACuriousMind I'm not convinced that India is producing a higher quality workforce than we (the west) are
 
1:02 PM
@0celo7 Never claimed it does, that's not the point
 
Their GDP is growing quickly, I'll give them that
@ACuriousMind I would be less worried if there was tangible benefit
I wasn't disagreeing with you
 
All they claim is to have a stronger theoretical education.
But even in that area I can't see the outcome
 
What does theoretical stuff have to do with engineering?
@YashasSamaga where I went to school, it was normal to take many of them
I took 11 AP classes
 
@0celo7 Engineering students here are just weakened Science students.
But still they're stronger in science than actual science students!!! Because top students mostly choose engineering over science.
It's complicated :)
 
Go France
Although France is really shit for physics research actually
 
1:18 PM
@ACuriousMind Is your AI-ness aware of what an "escort mission" is?
 
@0celo7 It's a mission where you have get some NPC somewhere without them dying. Very annoying if their AI is stupid.
 
@ACuriousMind Yes. Imagine having to do an escort mission with five children, one of which is crippled.
Imagine getting to the helicopter after about the 10th try, then getting in the helicopter...and then the helicopter flying off without letting the other four children get on.
@ACuriousMind But hey, look at this camera angle.
 
@Mostafa no data for china and India
@YashasSamaga are you an iitian
 
What is an Iitian?
 
@0celo7 I do recall reading about that in the reviews now that you keep mentioning it.
@0celo7 Someone who attends IIT, I guess?
 
1:27 PM
Oh.
 
@ACuriousMind yeah
 
@0celo7 Yeah, stupid game AI is annoying if it makes missions fail unnecessarily.
It's also pretty hard to get right, apparently.
 
@ACuriousMind I'm actually upset that this game runs on my laptop. I can play on 1280x800 with mid-high settings and get 60fps while only using 60% of my GPU, but TW3 was using 100% of my GPU on 720p while only getting 10fps >:(
 
I'm playing through TW3+expansions again right now, actually.
 
Grr
I have enough money for a gaming rig but I don't want to lose what's left of my free will
 
1:32 PM
@Koolman Almost sure that China and India are the first two (don't know the order)
 
@ACuriousMind When's the next Steam sale? I'm going to try to get TW3 to work again
 
@0celo7 Free will is an illusion, anyway :)
 
Oh please
 
@0celo7 No idea, I got it on GOG, they have sales sometimes, too
 
what about paying will
$5 for will
 
1:34 PM
@ACuriousMind I need a place with a good return policy.
Just download more free will
 
This list of top international rankings by country includes global-scale lists of countries with rankings (this list only contains sovereign states), sorted by country that is placed top or bottom in the respective ranking. == List == In order to limit the scope of the list and distinguish notable statistical indicators from trivial ones, entries in this list should contain a link to one of the following: A list of countries with the corresponding ranking An article which contains the corresponding ranking in one of its sections A global-scale map reflecting the corresponding ranking The following...
 
hi.all
 
@Slereah Reminds me of the Simpsons episode where Bart sells his soul
 
The Simpsons has that usual weird cartoon theology where all religions are true somewhat
 
@Slereah Hmmm... we should ask Serge Haroche about that.
 
1:39 PM
Why not ask me
I am in France right now!
 
are...the....tensor...products...in...quantum...mechanics...commutative?
 
I have quite an ambivalent view of the French system (in general). Some parts of it are truly first rate.
the rest is the rest... but it is really worse than other countries?
 
@Moses Depends on what you mean by that. Given a tensor product space $A\otimes B$, while $a\otimes b$ is an element of it for $a\in A,b\in B$, the object $b\otimes a$ is not, so it does not make sense to ask whether they are equal
 
@Slereah Some of the French science remains absolutely the best, in the way it is conceptualized and implemented.
 
However, there is an isomorphism of $A\otimes B$ to $B\otimes A$ that sends $a\otimes b$ to $b\otimes a$, so in that sense it is commutative.
 
1:43 PM
Hm, is there the equivalent of the principia mathematica for category theory?
Building all math from categories
 
@Slereah It's called "fully formal ETCS" I think, cf. nlab
 
Let's give it a looksy
 
Damn nlab
 
Instead of set theory, you have the Elementary Theory of the Category of Sets.
 
@ACuriousMind how many people actually understand nlab?
Or, what does one hope to prove with stuff on nlab?
 
1:48 PM
@0celo7 All of it? Probably no one? Most of it? Probably not more than a few dozen.
 
thanks
 
@ACuriousMind And the second question?
 
@0celo7 I think there's no one goal, given how much is on there. Some of it arose to address specific questions, some is merely recasting old things into what they call the nPOV, the viewpoint of higher category theory, because they believe it's an important unifying perspective on mathematics.
 
2:05 PM
@ACuriousMind Can one, say, prove something concrete that has a hard "classical" proof with an "easy" nProof?
 
@0celo7 Well, for instance modern derived algebraic geometry doesn't really have a "classical" formulation, I think. All those sheaves and stacks and whatnots are only available from a category-theoretic viewpoint to begin with.
 
28
A: Is it theoretically possible to shield gravitational fields or waves?

Luboš MotlIn a consistent theory of gravity, there can't exist any objects that can shield the gravitational field in the same way as conductors shield the electric field. It follows from the positive-energy theorems and/or energy conditions (roughly saying that the energy density cannot be negative). To ...

I don't understand two bits of Lubos's answer:
 
I don't really understand higher category theory, so I cannot tell you whether there are "easy" proofs of old assertions, but taking a category-theoretic viewpoint is usually a tradeoff, in my experience - some things become easier, others become harder.
 
What becomes easier is what I'm asking
 
I think the Frontiers in propulsion physics book has designs for gravitational shielding
But like most GR designs, the energy requirements are ridiculous
 
2:13 PM
1. Why the requirement that spacetime is dynamical will mean negative mass cannot be present. I mean, we can (naively) plug negative mass into the gravitational time dilation equation to get a time constriction effect. Therefore the spacetime between a negative mass and a positive mass should cancel out to flat spacetime. I do not see how that will imply spacetime will lose its dynamical properties as Lubos claimed
 
@0celo7 One instance I know is that the existence of fiber products of schemes is rather technical in the classical view of schemes, but becomes very obvious if you view them as their equivalent "functors of points".
 
He only says that negative energy implies unstableness of the vacuum
Which isn't 100% true but it is mostly true
if you allow an unbounded from below hamiltonian you get weird processes like the vacuum radiating energy away
 
2. Why must the vacuum be stable and cannot spontanenously flucturating with positive and negative energy, analogous to fluctuations of matter and antimatter particles? We knew that the casmir effect is one of the experimental evidence of vacuum flucturation of particle antiparticle pairs (and possibly other quanutm fields), but what in experiments that we have (yet?) to observe that rules out flucturation of positive and negative energy quantum fields?
(sorry typed too slow, let me read your ans...)
Ok, so you mean we would have observed radiation spontaneously produced from the vacuum whenever the corresponding negative and positive energy quanutm fields flucturate in an analogous manner to antiparticles/particles? But the fact that we don't see such spontenously radiation events rules them out?
 
IIRC the classic screwy Hamiltonian is Klein Gordon with a cubic interaction
Particles and antiparticles are not a problem at all since both have positive energy
There's no link at all
In $\varphi^3$ theories you get tadpole diagrams that are non-zero
an easy way to see the problem is to look at the path integral
 
@ACuriousMind Why would I need a fiber product of schemes?
 
2:21 PM
The phase term will be (in the Euclidian version) $\approx e^{-\int \varphi^3}$
There are tons of configurations where that phase is positive and will just blow the fuck up
 
Ah I see...
 
you big liar
 
@Slereah language please
 
That is the technical term
You can check Hawking-Gibbons
 
@0celo7 Because it is very natural to consider schemes over another (e.g. the scheme associated to the base ring) and you'd like some sort of product that takes two schemes over X and gives another scheme over X and the naive Cartesian product doesn't do that, unfortunately
Take everything I say with a grain of salt because my algebraic geometry is a bit rusty and never was very good to begin with :P
 
2:25 PM
"The path integral of the conformal term of the action in Euclidian gravity will blow the fuck up"
- Hawking, the blowupiness of the Euclidian Hilbert action
 
I need evidence
 
1974
Obviously a fine technical term
Cebanov-Fucks Distribution
 
Well... I do have *tried* (but failed) to read scalar QFT a few months ago. Even it is quite fail because I am completely unaware of the concept of fock spaces, I do think I have read and learnt bits that are relevant. I also still have residual knowledge of GR form my undergrad course, Ocelo7 and Johnrennie's conversations. This plus a bunch of googling and PSEing will usually help me to achieve an understanding to 1st order of something that I have little background of.
Higher order understanding will then arrive once I fill in those gaps
 
Dumb question: oxides of sulphur,nitrogen,carbon… means oxides of sulphur, oxides of nitrogen,oxides of carbon or oxides of sulphur , and nitrogen , carbon…?
 
Hello
 
2:30 PM
"The main strategy there was decomposing the Gel'fand-Fucks cochain complex into irreducible factors and picking up the trivial representations and their concrete bases, and ours is essentially the same. "
I wonder if that's the same Gel'fand as the QFT one
Good to know he did some Fucks work
Although apparently the standard spelling is "Fuks"
 
Hello... M
 
Dmitry Borisovich Fuks, for his full name
 
Does that mean that Fucks is an allowed word now?
 
It's a perfectly valid variation on it, apparently
Here he is
on the right
And Gelfand is apparently indeed the same Gelfand as the GNS construction one!
 
@0celo7 There are no allowed or forbidden words. What matters is not the words themselves but what you say with them.
 
2:37 PM
also the Gelfand triple
 
0
Q: is intrinsic spin conserved?

S.CHis intrinsic spin conserved?why? I would like to know how can we ratiocinate this concept with the help of Symmetry and Conservation Laws in physics.

The one and only use of 'ratiocinate' on this site.
Seems like the guy learned from these other guys
(which link, btw, might be interesting for @DanielSank)
 
@EmilioPisanty what does that even mean?
 
Sid
Hey all! I am new here. So, a bit of help please..
 
> Definition of ratiocinate
> ratiocinated; ratiocinating
> intransitive verb
> : reason
@Sid ask away
@0celo7 as to why people say 'ratiocinate' instead of 'reason', well...
you'd have to ask the Indian Supreme Court, for one
 
Sid
Well, It was mentioned in the Question FAQ that "Ask questions that can be answered and not discussed". So, What exactly do you mean by answered and discussed? Subjective and objective?
 
2:49 PM
@Sid roughly, yes
it's impossible to give hard definitions that work in all cases
have you got something specific in mind?
 
Hi @YashasSamaga
 
Convex lens in our eyes form inverted image but we see erect, why?
 
@Ramanujan 'cause our brains are smart. What you perceive is wildly different from the naive optical image that forms on your retina.
 
Sid
Okay, I have got a question, but I am not sure, if it is a fit for the site. "Say,there is a current-carrying loop in a time-varying Magnetic field. Now, As Magnetic field is varying, there would be a change in magnetic flux and hence, emf would be induced in the loop by Faraday's law. Since, emf is induced, there is a net Electric Field. Now, would the motion of the loop be different if I first place it in a uniform magnetic field and uniform Electric field at the same time?"
 
Lamp is lighted in the running bicycle but it goes off when the bicycle is stopped, why?
 
3:06 PM
@Sid that's nowhere near the 'discuss' side, so you're safe from that
but it's not particularly clear what you mean by the last sentence.
 
Sid
What I mean, is that initially, there was a time-varying magnetic field and a loop entered with some velocity(Yes, I didn't make that clear, initially, but that's what I mean), So, it undergoes some motion. And since, there would be an Electric field induced, it also has motion due to Electric field. Now, what if the loop enters into a Uniform Magnetic Field and Uniform Electric field acting at the same place, would it make any difference to its initial motion?
 
@EmilioPisanty they actually write like that?
I don't see ratiocinate in there
 
Hello @JohnRennie
 
Hi :-)
 
Sid
Is it Fine, if I post that question on the main site?
 
3:17 PM
A thin copper tube of outer radius 0.5 cm carries a liquid flowing at T - 100°C. The copper
tube loses hest according to Newton's law with constant of proportionality 3x$10^{-3}$cal/cm$^2$sec°C . The temperature of surrounding is 20°C. Now we coat n layer with thermal conductivity 2.8 X 10$^{-3} $ cal/cm°C sec. The layer is 0.5 cm thick. Assume that outer surface of layer loses heat with same constant of proportionality .We have to find the ratio of rate of heat loss .
Can anybody help me in this
 
@JohnRennie, why does a transformer not alter DC voltage?
 
@Ramanujan I'm eating my lunch at the moment. let me get back to you on that one.
 
@ACuriousMind Based German language
 
@JohnRennie,ok
 
The German title for SW8 reveals there are multiple last Jedi
If it's just Luke and that girl I will be upset
I need Mace Windu back in my life
 
3:22 PM
@0celo7 Not necessarily, it might e.g. possibly refer to Luke making some people new Jedi during the movie, no?
 
Whatever happened to Jaba the hut?
 
Are @skillpatrol and @skullpetrol same?
 
Naked princess lady killed him
(Can't spell her name)
(Autocorrect keeps telling me I mean leash)
 
@Fawad perhaps ;-)
 
Sid
Why isn't there a tag wiki on "Electromagnetic induction"?
 
obe
3:35 PM
sup
 
chillin, you?
 
obe
slept in and now I dunno what to do xD
 
@0celo7 yeah, those are direct Indian Supreme Court quotes
go to the link for more
 
@JohnRennie, Hello
 
@Sid tag wikis are unfortunately not one of the better-maintained aspects of this site
@Sid that's an on-topic question, for sure
it still sounds confused to me, but you can definitely ask it on the main site
 
Sid
3:43 PM
Huh? Well, tag-wikis are pretty well-maintained in Puzzling. I assumed it would be the same here.
 
@Sid the SE network is wide and varied
 
Does a positronium ion have a proton
@everybody
 
@satyatech no
it's a lone positron
positronium (neutral) is a positron and an electron
@0celo7 OK, yeah, no ratiocinate in the full opinion, but still
I'd put some money on the claim that you'll find it with some moderate text mining on that database
 
@EmilioPisanty so it's this "Indian English" one hears about?
 
@0celo7 potentially?
 
3:56 PM
Otherwise I don't see what the Indian Supreme Court has to do with this
 
I wouldn't want to generalize without knowing, so I won't
but I did hear from my brother that it was fairly common for folks to say "the proprietor is not available" in situations where "the owner isn't here" would do
you'd have to ask @Kaumudi.H how common it is to have that sort of language in India
 
Sid
Well, I am an Indian, if that helps..
 
@Sid any thoughts on how unduly bizantine those quotes above are?
 
Sid
Whoa. At least those things aren't heard from the common locals around.
 
@EmilioPisanty It's a metaphor for their educational system: overly complicated.
 
Sid
4:04 PM
Overly complicated? Please elaborate
 
@Sid There's so many tests and schools and levels and it's all insane
people taking years off just to study for tests
 
Sid
Well, you have to qualify tests to get into colleges.
There is no alternative for that
 
obe
there isn't?
 
I don't think the German system works like that
can @ACuriousMind clarify?
In America, you need a certain score, sure, but the exams are not insane
 
obe
in canada we have no qualifying tests for university whatsoever.
 
4:07 PM
@obe Well, Canada is the size of a moderate-sized Indian village in terms of population.
 
obe
don't worry the population is increasing because of your president.
 
@obe How many visas has your government granted because of Trump?
Last time I heard, it was a big fat zero.
 
obe
lol they won't grant them "because of trump"
 
How many new residents has Canada received that aren't islamists?
Although if you want to take ours, that's fine I guess.
 
obe
lmao
seriously?
 
4:11 PM
@0celo7 It's a bit difficult to explain. If you have completed a school degree that allows you to study at a university, then usually there will be no more qualifying tests. Usually, either the total score of your school degree or the individual grades in individual subjects will determine admission to a specific course at specific unversities, but barriers are fairly low except for "high-profile" subjects like medicine or law.
 
Sid
Okay, see, every year, close to 1 million students give JEE(Engineering entrance) exam and 600,000 students give NEET(For admission into medicine course). Out of those, First 200,000 students qualify in JEE and give another "Advanced test" out of which around 20,000 students are taken in to the premier engineering colleges and 50,000 are taken in for medicine course. How else will you choose 50,000 students from a million students?
 
@Sid I'm aware of the numbers.
India is huge, I get that. Doesn't make it less insane.
 
obe
@0celo7 not all refugees are relgious dude, and not all refugees are from islamic countries. also there are more ppl immigrating to canada than just refugees.
 
@obe Where are refugees coming from that are not from Islamic countries?
Genuine question.
Ukraine?
 
Sid
@0celo7 I don't argue with the insane part. What I am telling is, it is the necessary evil at the moment. There is no alternative for us, right now.
 
4:15 PM
@Sid I agree.
What do the people do who don't pass the JEE?
 
Functional integration is a collection of results in mathematics and physics where the domain of an integral is no longer a region of space, but a space of functions. Functional integrals arise in probability, in the study of partial differential equations, and in the path integral approach to the quantum mechanics of particles and fields. In an ordinary integral there is a function to be integrated (the integrand) and a region of space over which to integrate the function (the domain of integration). The process of integration consists of adding up the values of the integrand for each point of...
 
Are there even 200,000 new engineering jobs every where?
 
so that's how they are defined
 
obe
@0celo7
 
I think one aspect of the lower barriers is that not everyone is expected to go to university. It's a rising expectation in the last decades, but still, it's not obligatory and I know a sizable amount of people who could've gone to university and chose to learn a trade instead.
 
obe
4:16 PM
you have a point there though.
 
320 "refugees" from America LMAO
 
obe
xD
 
@obe 2014.
That's before Trump
I thought Obama was inclusive?
 
Sid
@0celo7 Well, If by pass the JEE, you mean, not get the qualifying marks for the next level, some of them study for years to pass it while others take admission into private colleges(which means they pay a hefty amount to get a degree) and very few go for MSc, I believe.
 
obe
it should look about the same but larger numbers and some extra countries.
let me try and find a 2017 one
 
4:18 PM
@obe You will see Syria explode I imagine.
last year they brought in at least 10,000 I think
@Sid how do you get an MS if you don't get into college?
 
obe
wait can we ignore refugees
 
Sid
Of course, they get into college. MSc does not depend upon JEE scores. Universities accept students on basis of Marks received in Grade 12
 
obe
there are about 300,000 immigrants coming in 2017. IIRC that's the usual number.
most of them are normal people from a diverse number of countries.
 
ok, so 300,000 more
 
obe
thing is, your president will make more skilled workers feel safer coming to canada instead of the usa.
 
4:21 PM
India is still 20 times larger
 
obe
you can't deny that xD
 
My response to that would violate chat rules.
 
obe
okay let's end it there then
 
So I guess I won't respond.
 
obe
I dislike politics
I washed a hand made wool sweater and it became stiff after it dried.
 
4:23 PM
@ACuriousMind Quiet is basically a get-out-of-jail free card
If you're about to be discovered, order her to snipe someone
The whole enemy force will charge her position, and she just teleports away
 
obe
@0celo7 know any chill songs?
 
yes
 
obe
link?
 
I'm in class
 
obe
later then.
 
obe
4:44 PM
hi @skullpetrol @skillpatrol
 
Hi pal @obe
How are you doing?
 
obe
bad
well
 
wazzup?
 
obe
idk
I need to get my shit together
 
language
 
obe
4:48 PM
lol
 
what is funny?
 
You.
 
A proton captures a muon .Find the radius of the first Bohr orbit of this atom.
@Everybody
 
user228700
@0celo7 Isn't this place PG 13?
 
@Kaumudi.H G
 
obe
4:50 PM
 
user228700
@0celo7 ?
 
G is for rated for a General family audience.
The "cleanest" rating.
 
This room is a not a product to be consumed for entertainment and is not rated at all :P
 
obe
@ACuriousMind can you delete my link about 0celo7 ^
 
::stops making popcorn::
 
4:54 PM
@obe I could, but why would I?
 
obe
idk I think it's not very nice.
I regret posting it.
 
@obe not me
 
obe
oh
 
I don't know who this imposter is, but it's pretty evil
 
Gaming?
 
4:56 PM
@ACuriousMind Can you please ban this fake 0celo7
 
@obe Everyone's utterances in chat are a matter of public record, we all have to live with the possibility of someone quoting them at us.
 
obe
@ACuriousMind well it's not the real 0celo7 in this case :p
 
@obe It is, just click on the name to see it's the same user profile.
 
that's what's so evil about it
ban him!!!
 
obe
@ACuriousMind I used the sarcasm emoji lol
oh well
 
4:58 PM
Never mind
 
(removed)
(moved to the trash)
 

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