@anonymous both links are teh same

@user400188 have you posted yet?

@Kenshin

ok cool

+1

@Kenshin Hmm. Copying error it seems. Read ten messages up and down. You will get the reference.

@user400188 perhaps if you come back in 12 months there may be an answer

wow that's rood

gasp

no way

they should have more understanding that this quiz is important to you

@Kenshin Yeah

wtf

invaders?

what does he mean

For pity's sake people let it go.

I'm just curious

invaders?

does he mean invaders to the chat room?

@Kenshin probably.

this site should be welcoming people who are learning physics

As a user who only just entered Physics stack exchange; I must say I am somewhat intimidated by that conversation...

Speaking as a room owner no-one will be banned for talking about JEE work. However people may well get banned if the argument about JEE work turns ugly.

I suggest letting it go like John has said

@JohnRennie do you have banning powers?

I am willing to let it go unless someone pings me about this issue again.

this is the first I heard about the issue

I'm disgusted

I really want to stop this JEE hype or whatever it is

I think some people need to be banned

JEE gate

@Kenshin I have kick-muting powers i.e. up to a half hour suspension

can you mute a moderator?

lol

Good question, and the answer is that I don't know as I have never tried. Attempting this may bring my career as a room owner to a premature end :-)

lol

well if a mdoerator is out of line I think it should be fine

Probably mods can remove the suspension by themselves.

They can be suspended though

I read it on meta

There was a mod on the SciFi chat room who managed to get suspended

He is no longer a mod :-)

lol

Who do you think has more power, the popularity and high reputation of John REnnie or the abilities of moderators?

@JohnRennie why he has done that

it would be like Bill Gates vs the government

Lol

@Koolman I think he lost his temper in the chat room and posted some intemperate messages. I don't know the details and frankly I don't want to know as it wasn't an edifying spectacle.

such a pacifist @JohnRennie

I would say you lot have an unfairly negative view of the mods. I see the mod discussions about the chat room and there is a huge amount of debate takes place before anyone is suspended. It's not done just because a mod is having a bad day.

pls post here

@JohnRennie how many people get banned out of the number of people proposed to be banned in moderator discussions?

@anonymous any idea

what a coincidence

we were just talking about JEE

@Kenshin yeah I know

@Koolman Google search the products. You'll find it...

Well, it's 09:26 on a Friday morning and I have finished work for the week. I think this calls for a coffee. A biiiiiiiiiiiiiiiiiiiiiiiig coffee :-)

@anonymous what I will do in exam

@Koolman Derive it. You need to remember some basic stuff.

All those reactions are available on the net

@anonymous in the solution it given as .K2SO4 is a salt of a strong acid qnd strong base . So the electrolysis of K2SO4 is the electrolysis of water

@Koolman Even NaCl is same. But in NaCl, NaOH is produced too

Check out the reactions...

@Koolman that is true

@anonymous how

@anonymous that is true but how does it explain the answer?

There is no strong acid or base produced here

Language

Russian :P

the question asked which remains neutral :/

I still don't understand

Goodnight everyone.

@YashasSamaga Why do you think K2SO4 doesn't give neutral solution?

Why doesn't NaCl doesn't give a neutral solution?

OMMMGGG

The neutral was about pH

I was thinking of charges

@anonymous does it mean reaction will always towards less acidic or basic

@Koolman what?

no

In NaCl, you get NaOH, in CuSO4, you get H2SO4, in AgNO3, you get Ag(OH)2

As reaction always proceed from strong acid to weak acid

do you think there will ever be a problem in your life/work where you have to know the answer to that question?

if not then your education is failing you

@Kenshin I have some made several kinds of electrochemical cells at home using the knowledge of electrochemistry . I make them as my hobby. That makes me happy. And there can be no bigger aim in life than to be happy.

@anonymous our education influences what makes us happy and what doesn't

@Kenshin My education certainly makes me happy :)

yes humans love to learn anything

but potentially one could be even happier if they learn something useful

@Kenshin what do you mean by useful ? Something from which I can earn money?

No something meaningful

happiness isn't everything

Electrochemistry is meaningful to me

To me happiness is everything

ok so tell me this

hello...?

@anonymous Do you go to a school?

0..0

would you rather live a life where you do nothing of importance to the wolrd but you play video games and are happy

or would you rather live an adventerous life where you are a hero and save the world, but you are less happy at many points during your struggle

to me the life of meaning is more important

@Kenshin Video games don't really make me happy. And doing something for the world does make me happy. However that doesn't mean I will give up my hobbies to do something for the world.

I can do both side by side

my point is, I've been "happy" and unfulfilled

for me to be fullfilled I need more than just happiness

but perhaps I'm unique

For the time being I am happy and fulfilled. So I don't really need to worry...

well thankfully much of humanity has had a different attitude

if we were all happy as cavemen making fire we wouldn't have the technology we have today

@TsungyenTsai did you want to ask something, or just dropping by? :-)

@JohnRennie how old are you?

@Kenshin Has the technology made our lives better and happier? Then yes, it was a reason to strive for.

@takashi old

@anonymous well maybe one day we will have a "happiness" pill that you can take and society wont need to develop anything else?

screw solving any other problem once we have "happiness" pills right?

happiness is the be all and end all right?

seeking happiness and rationalizing your actions through happiness is a perfectly consistent philosophy of life which I don't believe in

It has an extreme offshoot, "hedonism", which is hip nowadays

@Kenshin Yes. Ask anyone who is addicted to narcotic drugs. Once they are happy (artificially) that's all they think about and long for. However, you need to differentiate between artificial happiness and natural happiness.

@anonymous why do we need to differentiate between natural and artificial?

happiness is happiness

is eating a pizza artificial because pizzas are man made?

is having fun night driving artificial because cars are man made?

@Kaumudi.H to be clear I'm arguing happiness isn't everything

@Kaumudi.H I'm showing how absurd it is to accept happiness is everything

I'm interested how you'd logically conclude that

Balarka, how who concluded what?

How you'd conclude happiness isn't everything I mean

@BalarkaSen well if happiness is everything, why does my conclusion need to be logical? As long as I'm happy it's fine

@Kenshin Because artificial happiness like drug dependency can make you unhappy in the future.

Such happiness is temporary.

@anonymous so humanity should strive to make a happiness pill that can be taken indefinitely without adverse effects

@Kenshin I am not claiming happiness is everything. I'm just interested in how you'd conclude that it isn't.

@Kenshin Yes. Without any side effects.

Which is what you seem to be claiming.

@anonymous why put so much effort into things like physics and engineering, we should put all our effort into devloping such a happiness drug instead

@Kenshin That is more tough than what you think.

@BalarkaSen because I will often make a choice that won't lead to my maximum happiness if I think it is the right choice. I'm motivated more than by happiness alone

We don't have the technology to make such a thing nor we ever will (probably)

@anonymous we should however focus much of our efforts on this, much more than what we are doing now though right?

we already have drugs

they are good starting point

@Kenshin Science can never get developed like that. All fields must develop equally.

now we just need to fine tune them

@Kenshin You are motivated more than by happiness alone. That doesn't mean everyone will be!

That seems like a personalized logic

@BalarkaSen that's right, I acknowledge I could be unique

@BalarkaSen and I agree @anonymous may well really be motivated entirely by happiness

@BalarkaSen but I can conclude that humans aren't all motivated by happiness alone, because I am a human, and I'm not motivated by happiness alone

Ah. I agree with the third sentence.

I wasn't entirely sure what the topic of the conversation was. OK, gotcha.

yeah glad we are in agreeance

2 v 1

@Kaumudi.H np Kaumu ask away :)

Ignore them, they are just jealous :-)

I don't recall any complaints about our conversations either

@Kaumudi.H don't worry Kaumu we love your food talk

there will always be people who complain about lots of silly things

be positive and you will be happier than they are

Daniel can't resist the temptation to wade into an argument. Unless he cites specific comments I would take no notice. I vaguely recall people have made what I considered joking comments, though I don't remember any specifics.

DAnielSank isn't even a mod

^ Exactly

We do talk more about food (you and JR) and philosophy (I, Kenshin, ACM, etc) and math (0celo7) in hbar than physics, at least to my experience. But that shouldn't be a problem.

Agreed

K and I talked for three hours about phase diagrams once ...

the h bar is for people who like physics, but where we can talk about anything

Yeah, I saw

Chat rooms are like any other social gathering. Insisting on your right to speak is, well, your right but that isn't necessarily going to make you popular. In everyday life we fit in with the people around us, and that seems to me a good way to approach the chat room as well.

A long and intense conversation isn't a problem if it isn't interrupting anyone else. If it is interrupting other people trying to discuss stuff then you might want to consider moving to a new room. But it's your judgement on what is the polite thing to do.

In the mean time my latest new PC is arriving in three hours!

Right. I think everyone is free to talk whatever until and unless it's not offending anyone.

I disagree Balarka

you can't help what offends someone else

for example

anonymous might be offended that I don't think happiness is everything

thgat shouldn't be my problem

Ah, fair point.

respecting one another is a good rule that I try to follow

There should be some kind of general conscience about offense however. After some point it's offending from most people's point of view.

yeah follow the golden rule as a rule of thumb

do to others as you'd have them do ot you

Two days. That's pretty typical for eBay sellers in the UK. People like to give a good service so you'll give them positive feedback.

Sadly there are no exciting laptops on eBay at the moment - life can be dull ... :-)

@Kaumudi.H Let it go. Lots of things got said in anger that wouldn't be said when people were thinking rationally.

It wasn't intended as an attack on us.

unacceptable, all users should be rational on physics.se

If not being perfect is unacceptable you have a lifetime of disappointment ahead of you.

hah, I don't actually know a lot of music bands

I made a great pizza last night

so spicy, fantastic salami

oh

ok

by

Bye!

$E = B times c$ or $E = c \times B$?

Hello chat!! .. quick question : why an electron scatters x-ray while an atom diffracts ??

E= mc^2

@BAYMAX cos that's the way the world works

@BAYMAX diffraction is a scattering process.

Any array of atoms, i.e. a crystal, diffracts because the scattered X-rays from all the different atoms interfere with each other and only produce a significant amplitude at angles where the scattered X-rays are in phase.

The scattering from a single electron and a single atom isn't that different

@John Rennie i thought it must be related to concept of atomic dimension...

@Kenshin yeah..that was funny..

The scattering from a single atom will be different because the atom and the electron have different sizes and different masses. However the difference is a matter of the details rather than the fundamental processes.

ok..thanks @JohnRennie

How would you define quantum field theory, informally

Is it like Hamiltonian mechanics + quantization process + maybe the existence of a ground state in a frame

Also the interaction picture business for perturbation I guess

@Kaumudi.H That was a logical argument to prove a point and not really an attack on food messages. If you read the transcript you'll get a gist of it.

@Kaumudi.H Hmm, neither do I remember disturbing any fully fledged conversation. As I said you are taking it literally. Don't.

@JohnRennie So how does stuff look for an observer that's accelerated for a finte time? Is their frame not described by Rindler coordinates?

@ACuriousMind locally it looks Rindler. Farther away it looks ... err ... I'm not sure :-)

I have to dash out to buy jelly beans (no, really :-). Back in 15 mins if you want more advice on GR from the master :-)

@JohnRennie Did you read the Wiki article on the paradox of the accelerating charge, in particular the strange allegation that the radiation is "hidden" behind a horizon for an observer co-accelerating with the charge?

@Kenshin If your E=mc^2 reply was for my question, I wasn't talking about energy :P

@Kenshin I was trying to find the correct direction for E, B and c of an electromagnetic wave

I know I was just joking dood

Hello @YashasSamaga

@Ramanujan Hi! What's your question?

@YashasSamaga, When two bodies of mass 50kg and 10kg are dropped from the same height, which will fall faster on the earth, why?

@YashasSamaga

:|

That is a 7th grade question

F = ma = mg

a = g

The acceleration is independent of the mass of the object.

,@YashasSamaga, air resistance is acted on both bodies and the shapes are not defined

They will hit the ground together.

Oh, there is air resistance?

The one with larger mass will reach faster.

The opposing force provided by the air is nearly equal for both.

@Slereah In and of itself, QFT does not need a definition that's different from the standard list of axioms of QM (Hilbert space, Born rule, etc.). An axiomatic approach to QFT cannot focus too much on quantization or Lagrangians and Hamiltonians - there are theories without global Lagrangians and many CFTs can also be defined without ever writing down an action.

@Ramanujan The one with higher mass will have lesser effect.

@YashasSamaga

, why 50 kg mass strikes first?

@Ramanujan If "the shapes are not defined" then the question is unanswerable if one includes air resistance.

@ACuriousMind

, why??

@ACuriousMind, does Aristotle idea of falling body work Here?

No.

@Ramanujan ...because air resistance depends on the exact shape? Without knowing the shape you cannot know how air resistance acts.

Don't listen to anything which Aristotle (and his group) said.

@ACuriousMind I honestly don't think the question requires the answerer to consider the effect of shape.

@YashasSamaga

, why?

@Ramanujan What? Aristotelian physics never works.

@ACuriousMind

,I was just asking. M

Or, at least, it is so fundamentally misguided that one shouldn't consider it in the first place.

@ACuriousMind

@Ramanujan The heavier the object, the more inertia it has. As the air resistance is nearly the same for both, the mass with higher inertia will have lesser effect.

,I have read about his idea of falling bodies tpo

But as ACuriousMind said, technically, it depends on the shape. The object which is more aerodynamic shape will face less resistance.

Air resistance and further pedantic considerations aside, note that there's a small difference between "falling faster" and "striking the ground first". They fall at the same rate because the gravitational acceleration is same for both objects. But they hit the ground first because $h = 1/2g t^2$; because $h$ and $g$ is the same for both, the time taken ($t$) to hit the ground is the same.

@YashasSamaga Why do you think that the air resistance is "nearly the same for both"?

So there's a little more to be said for the latter, I guess.

@ACuriousMind I have assumed they are similar stuff.

Without more specifications about the shape and material, you cannot assume that the drag coefficients for the 10kg and the 50 kg objects are similar.

The question cannot be answered then :/

If you leave it blank, you lose marks.

Who said anything about marks?

These questions appear every year in the board exams.

@ACuriousMind Hmm, you got a point.

@Ramanujan Does the question explicitly mention considering air resistance?

Ramanujan came in here and asked a question. It is unanswerable as written. I'm not going to pretend the question is well-posed or answerable just because some silly test author doesn't understand physics.

@Ramanujan Is it a CBSE board exam question?

@BalarkaSen the question says air resistance is acted on both bodies, and the shapes as well as sizes are not defined?

A@YashasSamaga, No..

Strange.

@Ramanujan Where did you get the question from?

While I was surfing through the Internet..

:|

I agree with ACM that the question is unanswerable