Calvin's Chat Room - 2020-08-12

Specter Prophet

1:29 AM

what is difference between classical and Lagrangian mechanics

Specter Prophet

3:19 AM

My Name is Doof and You'll Do What I Say for 10 Hours

►

abhas_RewCie

@SpecterProphet It's my pic, I just edited a bit to back and white... mood

@SpecterProphet In classical (Newtonian Mechanics) $F = ma$, In Lagrangian Mechanics, $$ \dfrac{d}{dt} \left ( \dfrac{\partial \mathcal L}{\partial \dot x} \right) - \dfrac{\partial \mathcal L}{\partial x} = 0 $$

$$ \mathcal L \stackrel{\Delta}{=} KE - PE$$

@Yuvraj Good Morning bhai :-)

Yuvraj

,.\]

abhas_RewCie

Technically, Lagrangian is also classical.

Specter Prophet

3:38 AM

looks like I need to read further to understand it may be it will take 3 days to finish classical mechanics if i hurry

@abhas_RewCie why black and white mood?

u look ahead of time to understand langrangian so may be u r gonna be top student in jee test

is jee done after graduating high-school or is it university test?

heard a lot about it

wow millions of student compete en.m.wikipedia.org/wiki/Joint_Entrance_Examination

1 math vs 4 physics lol

abhas_RewCie

3:54 AM

@SpecterProphet highschool

@SpecterProphet 1 math, 1 phy, 1 chem

Specter Prophet

4:59 AM

Good night

Captain Bohemian

7:27 AM

@SpecterProphet What I intended to say is if I could stay in that shop overnight, I could wake up having breakfast.

according to the eavesdrops I hear, there are some retired people who have high income and are very leisurely.

but I don't think these people would be glad to volunteer to be UberEats workers.

@SpecterProphet I think only Indians compete in JEE.

and I have lost interest in university entrance exam.

Captain Bohemian

8:21 AM

@CalvinKhor last night I saw someone in a Facebook PhD and postdoctoral positions group asked the question Which country is easy to get a Ph.D. position on a fully-funded scholarship?

Calvin Khor

8:40 AM

dont know the answer

Specter Prophet

9:56 AM

I know that I don't know anything.

I am writing wierd comments on hbar and math

good night

dude if derivative in terms of a variable of a function is 0 than it means the function is not dependent on the variable which we take derivative ?

the rate of change is 0

Calvin Khor

10:16 AM

yes

Captain Bohemian

10:39 AM

@CalvinKhor a lot of of people answer that question.

Calvin Khor

do you think any of them were right?

Specter Prophet

calvin is rigorous

Calvin Khor

@SpecterProphet can't sleep?

Captain Bohemian

@CalvinKhor no

Calvin Khor

lol

Specter Prophet

10:48 AM

@CalvinKhor sleep can't me not i can't sleep

amazon.com/Fundamentals-Optics-4th-Pub-Electromagnetics/dp/… cheap

Calvin Khor

looks cool

OLD BOY
5.0 out of 5 stars テキストでした
Reviewed in Japan on November 28, 2017
Verified Purchase
もう40年以上前、学生時代のテキストでした
試験はこの本の問題から出ました。
当時は　光学に関する成書が少なく、この本一冊で基本的な事は全て理解できると教授が進めていました
確かに初学者用ですが、この本を熟読すれば一般的には十分かと思います。光学は意外と幅が広いので
より深く知りたいのであればそれそれのテーマごとの参考書を読めばいいです。

lol

Captain Bohemian

@CalvinKhor everyone says the country in which they are given funded PhD position.

Calvin Khor

haha makes sense

any one person cannot answer a question about the statistics

Captain Bohemian

No one gives the answer I want to give.

Calvin Khor

would you get kicked from the group if you gave the answer

Specter Prophet

10:54 AM

@CalvinKhor u even speak Japanese ?

Captain Bohemian

So I don't want give my answer.

Specter Prophet

oh that's from review

Captain Bohemian

@CalvinKhor no.

Calvin Khor

@SpecterProphet LOL

Captain Bohemian

I have never asked a question in that group.

I think there are very few physicists active in Facebook.

So people in that group don't give answers about physics PhD position.

Specter Prophet

11:00 AM

sht i got 10 days to return to hell

bunch of textbooks unfinished

(ಥ_ಥ) I want to learn fundamentals of chemistry in 2 days 1000 page

1400 page sorry

I am doomed

Captain Bohemian

I think physicists seek answers better from SE or physics forum or other similar websites.

Specter Prophet

why are university book so long in page(ಥ_ಥ)

Captain Bohemian

No matter how long, as long as there are persistent food supply and health care, you can finish it.

Specter Prophet

time is the most important part here

Captain Bohemian

If no nobody supplies food and no doctors provide health care, nothing is possible.

Specter Prophet

11:12 AM

Terence tao finished PhD at 18 and me at 17 just starting undergraduate studies lol

Calvin Khor

at a young age people already knew he was good, so unfortunately that boat sailed a long time before 17

Captain Bohemian

@SpecterProphet because Tao had others preparing food and health care and money for him.

Calvin Khor

lol that's not the only reason

Specter Prophet

dude he has Monstrous IQ score

and perfect sat

Captain Bohemian

I could enter PhD earlier if there are people doing those for me.

Specter Prophet

11:16 AM

If i had pc earlier I think i can do equivalent to that may.... be :P

Captain Bohemian

Money is really the key for getting a PhD position in Europe.

Specter Prophet

we all can do that if we have enough resources

Captain Bohemian

A lot of professors said I can do PhD with them as long as I can get fund elsewhere.

Specter Prophet

I think the advantage was he had more educated parents which led him to liberty

Calvin Khor

what that means is they dont have funding for students, or don't want to use that funding on you

Captain Bohemian

11:20 AM

They said they have no position now or have no grant at hand.

You can't force them to produce a position for you.

Specter Prophet

they only fund to those which they might see potential in eg if u win gold in international olympiad in math hehe

or give them profit

Captain Bohemian

Not really

Specter Prophet

ok i don't know about funding and phd

Captain Bohemian

They would refer you to position application websites if they do have positions

But if they don't have positions, they don't even bother to see your profile.

Captain Bohemian

11:34 AM

I think I don't really need a personal PC as long as I stay in school.

I didn't have a PC until long after I graduated.

University always prepared very good PC for us.

Specter Prophet

70% fun 30% for educational things for me

I don't know if u can use pc 24 7 in university

Specter Prophet

12:10 PM

12

Q: Is there a differentiable function such that $f(\mathbb Q) \subseteq \mathbb Q$ but $f'(\mathbb Q) \not \subseteq \mathbb Q$?

Is there a differentiable function $f:\mathbb R \rightarrow \mathbb R$ such that $f(\mathbb Q) \subseteq \mathbb Q$, but $f'(\mathbb Q) \not \subseteq \mathbb Q$? A friend of mine asserted this without giving any examples. I seriously doubt it, but I had hard time trying to disprove it since anal...

real-analysis

looks easy to answer @CalvinKhor

Calvin Khor

lol

don‘t immediately know an answer

dont even have a guess if its true or not

Specter Prophet

hehehe u might have better chance

I don't want to waste my time writing or thinking about this question since it gained reputation so fast

so somebody might answer quickly

Calvin Khor

it gained rep quickly because its not easy

Specter Prophet

how do u know if it's easy or not?

Calvin Khor

its not a question from a textbook

or exam

and i have no intuition for it

often, real analysis questions you can solve 'by picture' and then work to make it precise

Specter Prophet

12:18 PM

I hope u r lucky enough to guess the function lol

Calvin Khor

lol

idk i wont spend so long

lol

Specter Prophet

I am thinking to make it irrational by some operation on the rational one

vaugely thinking

oh sht then I need to think

about other cases

Calvin Khor

the comments are now filling up with useless words lol

Specter Prophet

(T＿T) OK i don't know where to start with but I have some work to do in my own course

Calvin Khor

:P

Specter Prophet

12:23 PM

@CalvinKhor hehe u mean the comment in the question?

Calvin Khor

yep

Specter Prophet

I think the function maps sets to set other than only giving value which is not set

I might be wrong since I already forgot definition of subset lol

Calvin Khor

i think the solution will come from techniques that i do not know

so i will give up

Specter Prophet

I want to try it but I don't want to waste time (ಥ_ಥ) same goes to knight question

Calvin Khor

in maths chat?

Specter Prophet

12:27 PM

always start with superficial view

@CalvinKhor yes I rarely take other question seriously

I don't even take mine really seriously most of the time lol

Calvin Khor

lool

Specter Prophet

sloppy minded

will ya try it if he sets 10 k $ as bounty?

Calvin Khor

lol

yes

Specter Prophet

well the there will be more people to compete for 10 k lol the first on gets 10 k and other will get 0 lol

Calvin Khor

haha

maybe no

Specter Prophet

12:41 PM

may be this is the reason for millennium prize problem lol

Specter Prophet

12:51 PM

they wrote the answer

some 75k exp guy

Calvin Khor

ya

and the answer is clear

i was mistaken, i did have the tools to solve it

Specter Prophet

hehe I am too lazy to even understand answer

yep looks like u just need to know some basic tools from analysis

Calvin Khor

:)

Captain Bohemian

@SpecterProphet lab computers and department computers can be used 24 hours 7days.

Specter Prophet

brb God is calling me

Captain Bohemian

1:02 PM

Also,lab computers and department computers can be printed freely.

Specter Prophet

can be used to print freely?

Captain Bohemian

Yes

Specter Prophet

sounds good but can u download video game? have fun?

Captain Bohemian

Lab computers can be probably because they are like your own computers.

Unless you advisor is unhappy with you doing that.

Specter Prophet

now i feel like just reading whole undergraduate sht and go to PhD position lol

I can do anything I want to for video game

Captain Bohemian

1:08 PM

For me, my fun is almost educational.

I didn't have a lot time to play video games in my MSc studies.

Specter Prophet

dude imagine retiring at Young age and spend whole life playing video game... it's my dream

Captain Bohemian

I don't play video games for long.

Specter Prophet

man when u play video game u can see math

like modular arithmetic applies to screen

and can think about those reflection of ping pong bouncing blabla bla inequality

well very easy math only lol

Calvin Khor

lol

ping pong doesnt have complicated maths or physics

Specter Prophet

lol I know

ok but we can create complicated math from it who knows

Calvin Khor

1:24 PM

if you wanna call statistical physics a generalisation of ping pong, sure

Captain Bohemian

Beginning in the 1930s, scientists found that systole dampens pain and curbs startle reflexes.

Further work traced this effect to the fact that during systole, pressure sensors send signals about the heart’s activity to inhibitory regions of the brain.

Then that's unfair that some students felt less pain than me when being beaten by that inclement math teacher.

Specter Prophet

I came across stupid mistake in rudin

for every real x>0 and every integer n>0 there is one and only one real y such that $y^n=x $

false statements and proceeds to prove lol

Calvin Khor

1:40 PM

lol

Specter Prophet

ok in proof he writes $0<y_1<y_2$ -_-

man i was gonna ignore the proof for that stupid mistake

ok ok i am sure he did stupid mistake not mentioning it reading forward