The h Bar

anonymous

11:00 AM

@Kaumudi.H Countryside is obviously more peaceful and away from the hustle bustle :)

Slereah

Also cheaper

And all the scrumpy you can drink

John Rennie

@Kaumudi.H I do live in town, well on the outskirts of town, but Chester is a small city.

user228700

> Small city

user228700

OK...

John Rennie

In fact it is 1% of the population of Chennai (according to Wikipedia)

user228700

11:03 AM

Wow, that sounds nice, actually.

user228700

I love this city but I'm getting a bit tired of it--I've lived here for 18 years now.

John Rennie

I've lived in Chester since 1986 and I think I like it best of all the places I've lived in the UK.

user228700

1986?!

user228700

Holy cow, that's 31 years!!

John Rennie

21?

user228700

11:06 AM

Typos galore!

John Rennie

:-)

user228700

Holy crap, that is such a long time.

user228700

I'm Googling "Chester" and it seems that u guys have very tall buildings!

user228700

Or am I looking at the same building from different angles? :-|

user228700

Yep, that's the same building.

user228700

11:08 AM

Have u decided on lunch yet, BTW?

Slereah

HASTILY MADE CLEVELAND TOURISM VIDEO

►

John Rennie

@Kaumudi.H I actually don't feel very hungry. I'm thinking I might just have the risotto then make a special effort for the weekend.

user228700

Oh, OK :-)

John Rennie

@Kaumudi.H I think the tallest building is Chester Cathedral.

user228700

user228700

11:10 AM

^ This building kept coming up.

user228700

@Slereah "Come and look at both of our buildings" x'D

anonymous

@Kaumudi.H Looks more of private house rather than a shopping center as written at the front :-P

John Rennie

Those are only four stories. They aren't high by modern standards. The cathedral tower is 40m high - again not that high.

user228700

So many pretty places.

user228700

Most of Chennai looks like...how to put it mildly-- shit.

anonymous

11:14 AM

@JohnRennie In Chester are most of the buildings shaped like the one in K's picture? Are there cottages or skyscrapers ?

The architecture seems to be quite different from London

user228700

At least we have the Marina Beach...which also looks like shit but:

user228700

> With a length of 13 km, including a 6 km promenade, the Marina is considered the world's second longest urban beach

John Rennie

@anonymous those buildings are about 500 years old. Chester dates from Roman times, and we still have some of the Roman buildings left though they are mostly just ruins now.

user228700

John Rennie

The buildings in the picture are typical of the centre of Chester. They are known as The Rows. They are half timbered buildings.

user228700

11:17 AM

@JohnRennie Ah, that's why they kept popping up so much.

John Rennie

@Kaumudi.H Chester is near the coast, but there aren't any beaches - just mud flats!

anonymous

@Kaumudi.H wtf ! SO MANY PEOPLE!!!! Is that during a festival or something?

user228700

As of today (or yesterday perhaps, I'm not sure), I've been a member of SE for one full year.

user228700

@anonymous Perhaps, I'm not too sure.

anonymous

I've some questions about action of certain drugs. Should I ask on Chem SE or Biology SE ? :/

John Rennie

11:25 AM

If it's physiology then I'd ask on the Biology SE

If you just want to get high then ask on Life Hack SE :-)

Kenshin

@anonymous what's your question

@Kaumudi.H happy birthday

user228700

Dude, it's not my birthday x'D

Kenshin

yeah your SE birthday

user228700

Ohh. Um, thanks (?) :-P

anonymous

@Kenshin Why is Zantac better than Tegamet/Cimetidine in preventing histamine action ?

Zantac is ranitidine by composition

Kenshin

11:28 AM

define better

anonymous

@Kenshin When Zantac was discovered Tegamet lost its popularity...so something must have been better about Zantac

Kenshin

oh k

good quesiton

the answer might not be pharmaeeutical maybe it could be economical

@anonymous here is the answer: Ranitidine was found to have a far-improved tolerability profile (i.e. fewer adverse drug reactions), longer-lasting action, and 10 times the activity of cimetidine. Ranitidine has 10% of the affinity that cimetidine has to CYP450, so it causes fewer side effects, but other H2 blockers famotidine and nizatidine have no CYP450 significant interactions.

anonymous

@Kenshin Thanks. Source please! BTW why does cimetidine have more affinity than ranitidine ? Can it be explained using the chemical structure?

(Ranitidine)

Kenshin

do you mean affinity for CYP450?

anonymous

@Kenshin yes

(cimetidine)

Kenshin

11:35 AM

I dunno that's too detailed for me

anonymous

Oh its okay. Can you give me the source of your info ?

Thanks anyway :)

Kenshin

@anonymous

Ranitidine

Ranitidine, sold under the trade name Zantac among others, is a medication that decreases stomach acid production. It is commonly used in treatment of peptic ulcer disease, gastroesophageal reflux disease, and Zollinger–Ellison syndrome. There is also tentative evidence of benefit for hives. It can be taken by mouth, by injection into a muscle, or into a vein. Common side effects include headaches and pain or burning if given by injection. Serious side effects may include liver problems, a slow heart rate, pneumonia, and the potential of masking stomach cancer. It is also linked to an increased...

scroll down to the "History" section

paragraph 2 is what i copied but paragraph 1 is also interesting

anonymous

@Kenshin Great. I will read it . Thanks :) Bye

Sir Cumference

@Kaumudi.H I am now

Just woke up

0celo7

12:18 PM

@SirCumference LOW ENERGY

@Slereah I tihnk I'll be getting that wave equation book

@ACuriousMind Why is geometric quantization so bad? Hall says you can't even quantize the usual kinetic energy in general.

Why does anyone bother with it?

@Slereah link.springer.com/book/10.1007%2F978-1-4612-0337-7

Sir Cumference

@0celo7 Coffee!

0celo7

12:33 PM

@SirCumference I'm about to head to work and get me some coffee

Sir Cumference

Huh, you have a job?

0celo7

Yes, I think pretty much everyone knows I do.

Sir Cumference

Where you work?

0celo7

I'm a research assistant.

Sir Cumference

I'm a bit jelly

0celo7

12:36 PM

Do you not want to know what I do?

Sir Cumference

I'm guessing nuclear physics?

user228700

1:00 PM

Is Starbucks affordable for the middle class in the U.S?

user228700

400 rupees for one cup of coffee and a pastry--I could have a grand lunch with that much money!

Sir Cumference

@Kaumudi.H That's overpaying. I think it usually costs $3 for that in the US, though that number is just off the top of my head.

Still, I wouldn't pay 400 rupees ($6)

user228700

$3 for coffee and a pastry?

Sir Cumference

@Kaumudi.H Can't really tell off the top of my head, but that's what I'd guess

user228700

When I "grow up", I want to be the person who photographs food from restaurants and cafes for other companies.

user228700

1:05 PM

From what I find on Zomato, a person named Gaaya has bought every item on the menu to provide photographs.

user228700

@SirCumference That's so much more affordable, wtf! Here, one brownie costs north of 110 rupees.

Sir Cumference

@Kaumudi.H You'd think the people at Starbucks would think that's sketchy

@Kaumudi.H Again, I'm making those numbers up, but that's what I'd guess

user228700

@SirCumference What, why?

Sir Cumference

@Kaumudi.H That, or the person has a binge eating disorder

user228700

@SirCumference Nah, the (most) people of Chennai are warm and non-judgemental.

Sir Cumference

1:09 PM

@Kaumudi.H That's quite a contrast. Here in New York people will punch you in the face if you look at them in the street (exaggeration)

user228700

U live in NY?!

Sir Cumference

@Kaumudi.H Yeah?

user228700

That is quite a contrast to Chennai.

Sir Cumference

Certainly :)

user228700

I watched this video:

user228700

1:12 PM

Public Art Trip: New York City | The Art Assignment | PBS Digital Studios

►

Sir Cumference

@Kaumudi.H That makes NY look nicer than it feels, imo

user228700

> Nicer than it feels

user228700

Hmm, OK...

Sir Cumference

In fact, I don't remember the last time I saw sunlight like in that video

It's usually overcast

user228700

Ohh, OK...

Sir Cumference

1:16 PM

@Kaumudi.H Huh, I actually didn't know we had that much public art

user228700

Hehe, OK...

user228700

So many movies and T.V shows are based/set in NY!

user228700

Just look at this:

user228700

List of films set in New York City

In the history of motion pictures in the United States, many films have been set in New York City, or a fictionalized version thereof. The following is a list of some of the more memorable films set in New York City, sorted by the year the film was released. == Prior to 1910 == What Happened on Twenty-third Street, New York City (1901) The Thieving Hand (1908) Bolletje lulkoek (1909) == 1910s == Fatty at Coney Island (1911) Regeneration (1915) Lights of New York (1916) Coney Island (1917) The Delicious Little Devil (1919) == 1920s == Manhandled (1924) Subway Sadie (1926) East Side, We...

0celo7

@SirCumference No, I work for a psychology prof I had freshman year

we work on pain responses in small animals

Sir Cumference

1:21 PM

@0celo7 Oh, wow

Oh crap

I can't believe I fell for that...

0celo7

At least you're learning

back in the day I could have kept up the ruse for a week

Sir Cumference

;-;

0celo7

I work in solid state physics

Sir Cumference

Oh, that's neat

0celo7

@SirCumference So, I've been thinking about learning some cosmology

When I'm done with my current reading I don't really have anything planned

Secret

1:23 PM

What animal models you guys are using?
What subfield in solid state?

Sir Cumference

@0celo7 You should, it's really neat

0celo7

@Secret Mice, but we want to use children

Apparently it's very difficult to do human testing

Sir Cumference

Especially some nonstandard cosmologies like the Big Rip. Those are the most interesting parts imo

0celo7

there's regulations and there needs to be a state inspector, etc.

it's very expensive

Secret

Human testing is part of bioethics, one has to gain all sort of permit in order to research on that as well clinical trials

....Uh why the eerie silence....?

Seriously one cannot have a dam adapted to the ecosystem, similar to how we have migration crossings in roads?

0celo7

1:49 PM

> Of a symplectic Lie $n$-algebroid

??

@BalarkaSen @ACuriousMind Lol even n Lab doesn't understand this shit

Secret

2:11 PM

The following google search is inspired from reading the ACS report on the renewable energy sector from 2016 onwards

Quantum batteries can charge faster as entanglement shorten the distance in state space to flip the state from low energy to high energy states

In a sense, it kinda make sense as when an entangled state changes, all the subsystems's wavefunctions has to change in lockstep, thus minimising the number of steps needed to flip those states

The following acuriousmind either already aware or might be interesting to him:

1

Q: The Stone von Neumann theorem without exponentials?

Consider $\hat{r} = (\hat{x}_1,\hat{p}_1,\ldots \hat{x}_n,\hat{p}_n)^\intercal$ with commutation relation \begin{equation} [\hat{r},\hat{r}^\intercal] = i\Omega. \end{equation} I want a simple statement like: Any two irreducible representations of the canonical commutation relations are unit...

anonymous

Does anyone here know the answer to this (apparently silly) question of mine : physics.stackexchange.com/questions/310851/…

0

Q: Leading/Lagging terminology for sinusoidal waves

What is the method to identify which wave is leading and which wave is lagging from their equations? For example the two waves are $A\sin(wt+\pi/6)$ and the other is $A\sin(wt+2\pi)=A\sin(wt)$ (by trigonometric relations). So is the second wave leading in phase or lagging in phase compared to t...

waves

Balarka Sen

@anonymous At time $t = 0$, the first wave is at $A\sin(\pi/6) = A/2$ and the second is at $0$. So the first is obviously leading, right?

Note that a phase difference of $2\pi$ is the same as a phase difference of $0$. The "position" of the two waves are the same.

anonymous

@BalarkaSen Well, is that the way to define "leading" ? At t=0, the one which has greater magnitude will be called "leading" ?

I haven't found this definition in any book

Actually none of my books bothered to discuss it :P

Can you give me the source of your definition ?

@BalarkaSen I agree with the phase difference part :)

Balarka Sen

I don't have a definition, I just said out loud the most obvious thing I'd imagine is meant.

0celo7

2:26 PM

@BalarkaSen If I have some vector space $V$, can I find another vector space $W$ with $V=W\otimes W$?

Balarka Sen

Maybe someone can tell you the actual convention. Geometrically I think that should exactly be it.

@0celo7 No; think of a vector space with prime, or even squarefree dimension. Like $\Bbb R^2$.

Dimension is multiplicative under tensor.

0celo7

@BalarkaSen Exactly.

Wonder what I'm missing here

I'm supposed to take the square root of an $n$-vector bundle

Balarka Sen

That's only well-defined for line bundles, not? Otherwise, even if you can write it as a tensor product, it'll be of a different dimension.

0celo7

Oh, it's a line bundle because the elements are $n$-forms

Balarka Sen

Cool, then you're safe and sound.

anonymous

2:30 PM

@BalarkaSen Umm, suppose one wave A is $A\sin(wt+\pi+\pi/6)$ and the other wave B is $A\sin(wt)$. At $t=0$ the first wave is $A\sin(7\pi/6)<0$ while the other is just $0$. So by your definition $A\sin(wt)$ is leading $A\sin(wt+7\pi/6)$ ?

Balarka Sen

Yeah.

If you graph it, you'll see that would match the geometric intuition.

0celo7

@BalarkaSen So since my fiber is $\Bbb C$, I just use $\Bbb C\cong \Bbb C\otimes_\Bbb R \Bbb C$?

Balarka Sen

C \otimes_R C is not C!! C \otimes_C C is.

anonymous

@BalarkaSen That does seem like an easy to follow convention. Anyway, I am waiting for some more people to comment on the question. Thank you anyway!

Balarka Sen

@anonymous Right, better to check it through someone who actually knows their physics.

0celo7

2:32 PM

@BalarkaSen I'm confusing myself.

My bundle is real

so it's $\Bbb R\cong\Bbb R\otimes_\Bbb R\Bbb R$

Balarka Sen

Righto.

0celo7

Geometric quantization has too many definitions!

real bundles, complex bundles, Lagrangian submanifolds, Kahler forms, holonomies, polarizations, more bundles

everything flying around

For something that can't even make sense of $\frac{1}{2}mv^2$ in general!

@BalarkaSen so what is $\Bbb C\otimes_\Bbb R\Bbb C$?

Balarka Sen

C, as an R-vector space, is R^2. So it's isom to R^(2*2) = R^4.

0celo7

ah, yes

Secret

2:57 PM

ok so it seems Quantum discord is a measure of correlation between mixed states that is not due to incomplete information of the states

A readable review

0celo7

@BalarkaSen I was considering learning about symmetric spaces, or cats, but then there's this

Balarka Sen

You should do what makes you happy.

0celo7

I don't know what would make me happy

Balarka Sen

Well definitely figure that out

anonymous

3:20 PM

@BalarkaSen Do you do know about Young's double slit experiment ? I had a question on YDSE and JR is missing today :P

Balarka Sen

@anonymous I know a little, but not much. What's the question?

anonymous

In Young's Double slit experiment, if we use white light then what color will form closest to the central bright fringe? Most books say that the answer is violet as it has the shortest wavelength and will have constructive interference nearer to the center when path difference is $\lambda_v$. However, I feel the answer should be red as violet light will have destructive interference at $\lambda_v/2$ leaving behind the red end of the spectrum.

@BalarkaSen

This video contradicts with my answer though: youtube.com/watch?v=GEqwRBjHdwc

Interference Pattern for White Light

►

Balarka Sen

That's an interesting question.

anonymous

Yeah, its been bugging me for quite some time

0celo7

@Slereah I am beginning Wald

Balarka Sen

3:34 PM

@anonymous I am not sure I understand your argument though. Violet does have destructive interference at $\lambda/2$, so that bit of the band should be red. But why do you think it would influence the central band?

I have admittedly never thought about what happens to the double slit experiment if ones works with lights composed of multiple wavelengths.

anonymous

@BalarkaSen "But why do you think it would influence the central band?"...I never said anything about central band. Look at the video I linked. They are showing the blue/violet color appears nearest to the central bright. But I feel the first tinge of color (nearest to central bright fringe) should be reddish rather than bluish (due to destructive interference of violet)...

0celo7

how can you even compete with this typesetting

Balarka Sen

Ahh, I see, @anonymous. Well, I have no idea.

@0celo7 I think it's great

anonymous

@BalarkaSen I guess I'll wait for JR :).

0celo7

@BalarkaSen you have issues

Balarka Sen

3:39 PM

so do you

0celo7

you like the Milnor typeset too I bet

Balarka Sen

it's my favorite

anonymous

@JohnRennie When you return please do have a look at this question: chat.stackexchange.com/transcript/message/35324052#35324052

11 mins ago, by anonymous

In Young's Double slit experiment, if we use white light then what color will form closest to the central bright fringe? Most books say that the answer is violet as it has the shortest wavelength and will have constructive interference nearer to the center when path difference is $\lambda_v$. However, I feel the answer should be red as violet light will have destructive interference at $\lambda_v/2$ leaving behind the red end of the spectrum.

8 mins ago, by anonymous

Interference Pattern for White Light

►

3 mins ago, by anonymous

@BalarkaSen "But why do you think it would influence the central band?"...I never said anything about central band. Look at the video I linked. They are showing the blue/violet color appears nearest to the central bright. But I feel the first tinge of color (nearest to central bright fringe) should be reddish rather than bluish (due to destructive interference of violet)...

0celo7

@BalarkaSen I bet you like Spivak's font too

if your favorite font isn't computer modern, I'm not sure there's anything to be said

it's just a sad state of affairs

Balarka Sen

I haven't seen Spivak's font.

My favorite font is Courier New.

0celo7

3:42 PM

It might be the same as Milnor, I'm not sure

I don't have the books here

Balarka Sen

Yeah, that's great. Typewriter fonts.

0celo7

Why on Earth would that be appealing?

@Slereah Wald doesn't care about domains of operators. Low energy!

Never mind, he does.

Wdoctor123

4:12 PM

guys I'm finding out the relantionship between resonance frequency and height of the building. So I devised the eqaution F = k x H which than goes to log⁡(F)=xlog(H)+log⁡(k) and to F=k ×H^x. I found out x(gradient) to be -1.998

my question is does the gradient get affected by the material of the building?

anonymous

@Wdoctor123 have you tried with different materials ?

Wdoctor123

I don't have the time

now

I was just wondering because my friends got different results

anonymous

It should be affected by the material

Isn't that obvious ?

Wdoctor123

It is quite logical yes

but just wanted to know for sure

anonymous

I don't know the exact equation but logically the material should play a role

May I know why you are doing this experiment? Is it a project ?

Alpha Romeo

4:19 PM

0

Q: Ampere's Law Confusion

I had this question recently in a test. Different methods are yielding different answers. Can someone point out the mistake? We are given 4 infinite wires carrying current out of the plane as shown. Find $$\int_{-\infty}^{+\infty} \vec{B}\cdot\,\mathrm d\vec{x} ,$$ (along x axis) My logic f...

homework-and-exercises electromagnetism electrostatics electricity magnetic-fields

Plz take a look, i have exam next week

anonymous

@AlphaRomeo What does u vector stand for in the last few lines ?

Wdoctor123

it's a project

anonymous

@AlphaRomeo $\bar u (-3)$

@Wdoctor123 Oh. I see.

Wdoctor123

ye

so you study physics at university?

anonymous

@Wdoctor123 I'm in school..

@Ramanujan eh ?

Ramanujan

4:29 PM

@anonymous I thought you were accessing chat being in school right now :P

Wdoctor123

oh i confused with last person who helped me

XD

anonymous

@Ramanujan haha, no! i'd be kicked out :P

John Rennie

@Wdoctor123: as a rough guide the resonant frequency will be proportional to the square root of the stiffness of your building, and inversely proportional to the mass of your building.

So both the material the building is made from and the style of construction will affect the resonant frequency.

Wdoctor123

resonance frequency is also inversely proporptional to height

well that's what i found out during my experiment

anonymous

3

A: why do tall buildings have low resonant frequencies?

In order to excite a resonance in something, you need to produce oscillations that add coherently, or in phase. This means that when you vibrate on object, you will want the reflections of the vibration to add with the new vibrations that are coming in. These reflections will take time to get f...

John Rennie

4:33 PM

Increasing the height will decrease the stiffness i.e. it takes less force to deflect the top of a tall building than to deflect a short building.

Emilio Pisanty

0

Q: How orbitals exist in atom?

We know that there are 5 different kind of orbitals and we also know that these are regions of maximum probability where an electron can be. Orbitals are plotted on XYZ plane. So here my doubt lies, we show each orbital individually for the sake of understanding but how we visualize these for an...

quantum-mechanics orbitals

^ interesting mix of misconceptions

anonymous

@JohnRennie Did you have a look at my previous question about YDSE directed at you ? :) (I pinged you when you were offline)

vzn

@Emilio question/ wondering, not sure where to look, have you heard of laser experiments with "very long wavelengths"... what are the longest used?

John Rennie

I had a quick look and offhand I don't know how the fringe would look. Since the red intentity decreases more slowly as you move from the centre I'd guess the central fringe will get redder as you move away from its centre.

Is that what you are asking?

The first (non-central) fringe will be violet on the inside and red on the outside.

anonymous

@JohnRennie Why should that be ? Doesn't the destructive interference of violet occur at $\lambda_v/2$ (leaving behind the red end of the spectrum) whereas the constructive interference of violet occur at $\lambda_v$ ? I feel the first non central fringe should start with red on the inside and end with red on the outside and peaking towards violet at the center of it.

John Rennie

4:45 PM

Have you tried graphing the red and violet intensity on the same graph?

anonymous

@JohnRennie No. How do I know the intensity ?

And how does it play a role?