The h Bar

am i right on what i just said?

user218912

@MartianCactus yes but it would be 9/4 amps for the last 4 seconds.

user218912

not 9amp

Secret

6:04 PM

I trust you guys know what you are doing and that you are dealing with a system level entity: Synthetic ecosystems to fix tipping points in environemnts

...:P oh yeah

Ampere

The ampere (SI unit symbol: A), often shortened to "amp", is the SI unit of electric current (dimension symbol: I) and is one of the seven SI base units. It is named after André-Marie Ampère (1775–1836), French mathematician and physicist, considered the father of electrodynamics. The ampere is equivalent to one coulomb (roughly 7018624100000000000♠6.241×1018 times the elementary charge) per second. Amperes are used to express flow rate of electric charge. For any point experiencing a current, if the number of charged particles passing through it — or the charge on the particles passing through...

"For any point experiencing a current, if the number of charged particles passing through it — or the charge on the particles passing through it — is increased, the amperes of current at that point will proportionately increase." given in wiki

so maybe amperes ARE true for points

Physics Meta

0

Q: Next physics election

I understand a new moderator is elected whenever one steps down or there is an increase in traffic to the point that the current moderator team cannot handle it. However, my question is more about when physics.SE might reach that point - i.e., using the current rate of increase in traffic, when w...

user116211

@IceLord I note in my copy. So I prefer pencil and pen and my copy to a tablet.

user218912

@MAFIA36790 well I'm switching over to tablet once I buy one.

user116211

@IceLord ohh T__T

user218912

6:07 PM

I feel like sometimes I have ocd or something because I throw out a lot of paper when I make errors on it.

user116211

Most of my profs prefer hand written things apart from $\LaTeX\,.$

user218912

I think it's better for me to use tablet.

user218912

@MAFIA36790 I would use latex if I could type equations at @0celo7's speed.

user116211

@IceLord Use correction pen if you are using pen; but I would go with pencil. And also WTH are you bothered with doing errors?

user218912

idk

user116211

6:09 PM

We make errors when we are doing exercise; that's how we learn things.

user116211

And you dumb this in garbage; seriously?

user218912

recycling.

user116211

I love cutting the errors I made; it's a sign you are evolving.

user218912

@MAFIA36790 you're taking this way too seriously.

user218912

evolving, really?

6:10 PM

so when we say that the current flowing through a circuit is more like current flowing though every point on the circuit and as every point in a circuit experiences the same current as the wire is made out of the same substance and the resistance is equal...its like current flowing through every point on circuit is equal

user116211

Anyways, which tablet are you buying @IceLord?

that sounds overly complicated

user116211

@IceLord yeh; by rectifying your mistakes.

user218912

@MartianCactus I have no idea what you're talking about.

user116211

I should tell @IceLord, if you are sure to buy a tablet, go with Surface.

user218912

6:12 PM

basically you can define current as $I = \frac{dQ}{dt}$ which would be the infinitesimal current at a point.

user116211

That's incredibly awesome.

if current is related to a single point then how can we say that current is going though a circuit?

user218912

@MAFIA36790 I will buy an ipad pro.

and what do we even mean by a point XD

user116211

@MartianCactus What?

user218912

6:13 PM

@MartianCactus no think of the point as a surface actually.

it can be 2 billion atoms wide or 20 atoms wide...we can't define a point

user218912

since it's in 3d.

user116211

At least check the specifications of Surface Pro, @iceL:

user218912

@MAFIA36790 it's too big.

user116211

amazon.com/Microsoft-Surface-Tablet-Drive-Windows/dp/B00BE5T2TA

user116211

6:14 PM

@IceLord okay.

THE GREAT ANIMAL ORCHESTRA by Bernie Krause: Water Sounds

noice machine there

user116211

I generally prefer big tablets.

Secret

►

obviously an electron flowing through a space of 20 atoms wont be equal to the number of electrons flowing though a space of 2 billion atoms

@martian It's necessarily complicated to account for irregularities in the current through a circuit. If we only cared about the total charge going through the circuit in a total time, we'd be missing out on the information in between.

user116211

6:15 PM

@MartianCactus What?

what do we mean by a point?

user116211

Electrons don't work that way.

that is what i am saying

user218912

@MartianCactus I don't think you understand how electricity works.

then?

well...i studied electricity 6 months ago so i dont think so

user116211

6:16 PM

Its wavefunction that actually matters.

thats what book tells us, they "flow"

user218912

@MAFIA36790 nah not in classical electromagnetism or drude model.

idek what wavefunction is but have heard that term a LOT

Given a distance a sprinter runs $d = 400~ \text{meters}$ you agree he/she is running at different velocities at different points right @martian

user116211

@IceLord I thought we were talking about QM.

6:17 PM

that thing is not working

the symbols that you are writing are not translating

math.ucla.edu/~robjohn/math/mathjax.html

user116211

^^ chatJax @MartianCactus

what do i do?

user116211

@MartianCactus Bookmark it in the bookmark bar.

user218912

@MartianCactus bookmark it and then click it on this page.

6:19 PM

i cant

user218912

drag it to your bookmark bar.

i open the link and it says abput;blanl

anyway, d = 400 meters. So, if you want to know the velocity of the sprinter over a certain distance in the middle, say 10 meters long, you would calculate the time it takes for the sprinter to pass that 10 meters, right @martian ?

oh

user218912

@MartianCactus don't open it...

user218912

6:20 PM

lol

Bernard Meurer

Sup folks

done

Qmechanic

@DanielSank : It seems you're are not appreciating how much moderator work I actually do, much of it behind the scene. Concerning meta participation, I have written 86 meta post and I'm currently listed as the 16th most active meta user.

what do i do now?

write some symbols

user218912

@MartianCactus learn latex.

user116211

6:21 PM

Are you in mobile @MartianCactus?

no pc

user218912

basically put your formula in between $ $ symbols.

im on pc

oh

%2+2%

$2+2$

user218912

yes.

didnt work for me

user218912

6:22 PM

click the bookmark

user218912

then it will load

@Obliv yes we will

OK then you agree if you make the distance smaller and smaller you will get a point at which the sprinter crosses?

$2+2$

user116211

6:23 PM

i clicked

but still no

Bernard Meurer

@Qmechanic What about Manisheart?

user218912

@MartianCactus bookmark it and click it on this page.

user218912

so click the bookmark basically.

then it's the velocity $\frac{dx}{dt}$ where $dx$ is the distance the sprinter crossed in the time $dt$. The same goes for the current in a circuit defined by $\frac{dQ}{dt}$

@Obliv crosses what?

user218912

6:24 PM

the instructions are there... it should be simple if you know how to read.

the finishing line? then yes

omg no symbols trasnlating xd

I give up.

back to studying

user218912

@Obliv lol

user218912

@MartianCactus what grade are you in?

user116211

@icel; All the best for your new tab :)

6:25 PM

oh now theyr loading thx

user116211

I'm in Abstract Algebra again.

user218912

@MAFIA36790 thanks I'll probably buy it this weekend.

im in 10th grade

user116211

@IceLord Upload a pic of the tab ;P

user218912

@MartianCactus learn calculus first.

6:26 PM

i did it

user218912

then why don't you understand what Obliv is telling you?

they ARE translating

i have too many bookmarks so they just werent in the tab and it didnt k=work the other way

oh

so like, we are comparing amperes with speed there

so it 1 ampere is when takes 1 coulomb of charge to completely go round the circuit and come back to the same position in 1 sec

sorry, i am a struggler at understanding stuff :P

user218912

@MartianCactus no that's not how we define it.

i tend to stuck up with stuff that hasnt properly been explained

o

oh

but thats what @Oblic said

@obliv

user218912

>amount of current that passes through any point in the circuit through a given time interval

user218912

6:30 PM

that's what Obliv said.

that may vary

user218912

but he means charge.

considering what resistance the point has

that's how you can define it $I = \frac{\Delta Q}{\Delta T}$ @martian but it's more properly defined as $\frac{dQ}{dt}$

@iceL yeah I meant charge.

@MartianCactus yes that's the point. If the resistance varies then it's important to know the current at each point in order to determine the resistance.

yes charge

6:33 PM

of those sections

but amount of current that passes through every point varies acc to reisistance

user218912

@MartianCactus it doesn't vary at a point.

and if the current varies on diff. points in the circuit, then how can we calculate the overrall current flowing thourgh the circuit?

PhD level E&M o.o

well acc. to this definition. current is defined as the coulombs flowing through a point /second

6:35 PM

@martian the overall current is what you described before. You take the total charge that passes through the circuit divide it by the total time it took to reach the end.

and coulombs flowing though a point may wary withr esistance

oh

so current flowing through each point and overall current are not necessarily the same

it depends on the point you choose

user218912

@MartianCactus right.

user218912

if the resistance varies.

by the MVT theres a point in which the overall current and a point current is the same

user218912

6:36 PM

@Obliv that too.

the current towhich reaches the positive terminal frm the negative terminal/sec

MVT is PhD level math

what is MVT?

oh

@0celo7 I'm going to do my thesis on triple integrals

@Obliv Fuck...good luck

user218912

6:37 PM

@Obliv yes because triple integrals are ph.d level math.

but wait

I'm doing mine on double integrals

user116211

@MartianCactus, See, current density $\mathbf J$ at $t$ can be expressed as $$\mathbf J(\mathbf r, t) = \int \rho(\mathbf r_1,t)u(\mathbf r_1,t)~\mathrm d\mathbf r_1\,.$$

user116211

Can you now go to $I$ from this?

user218912

@MAFIA36790 wow that's so helpful for him.

6:38 PM

@0celo7 that's actually pretty impressive. we should collaborate on a paper together

"On the volumes of 3D objects"

user218912

@MAFIA36790 everything became so obvious now that you showed him that equation.

omg that equation is FAR beyond my lvl

user116211

@MartianCactus Okay you know $$I = \int_\mathrm S \mathbf J\cdot \mathrm da\,?$$

no now i understand

and no i dont know it

thank you guys!

@mafia stop scaring high schoolers with multi-var functions

user218912

6:41 PM

@MAFIA36790 it's clear he doesn't know basic calculus, so asking him that is like showing off.

the thing is....I ask everything that the book doesn't proves and just "tells" us

and squiggly S'

user116211

@Obliv This is undergrad study.

and the answers that I get are all straight out of quantum mechanics

and I don't understand them

user116211

@MartianCactus No need of QM.

6:42 PM

@martian yeah that's a good idea. Though you will probably not get all of your answers since some explanations require a solid understanding of the material you're learning

like this one physics.stackexchange.com/questions/284054/…

user116211

@IceLord Well, I'm not showing off ;P This is actually covered in early undergrad books like Purcell or Feynman.

i know..but whats undergrad?

collage level?

yep

@MAFIA36790 Seems wrong.

user218912

6:43 PM

@MAFIA36790 okay... he's in grade 10.

The left side is a a vector, the right isn't.

@IceLord wtf doing PhD level EM in high school O.O

WTH!!?!

user218912

ikr

so if I choose to go in the field of technology development(electrical engineering to be precise) then is there ANY chance that they will teach me QM?

user116211

@MartianCactus No idea.

ah man i want to study it

user116211

6:45 PM

Maybe; you can always take extra classes.

maybe a really brief introduction to some concepts.

user218912

@MartianCactus read a book on it yourself.

user116211

@0celo7 my bad. Written in haste.

but nothing a pure physics degree would make you learn

maybe

obviously i can take extras :P

no i dont want degree..i believe that u become a better engineer if you understand more

user116211

6:46 PM

Anyways, I'm off for now. Good night all.

@MartianCactus take an elective

@mafia cya dude

ok so the current flowing through every point in a circuit is diff. but the overall current flowing throuh the circuit is the charge flowing frm negative to potitive terminal/sec

what is elective?

user218912

@MartianCactus you're kind of right.

user218912

okay that's good enough for your level.

6:48 PM

@MartianCactus Read

amazon.com/Principles-Quantum-Mechanics-2nd-Shankar/dp/…

omg im in 10th class

will i understand it?

user218912

no.

oookkk

user218912

learn basic calculus first

well can you elective thing in 10th class?

user218912

6:49 PM

then you'll understand it.

yes i wanna do calculus

user218912

learn it then.

user218912

right now.

@0celo7 1 or 2

but im reading a book on basic electronics and it includes integrated circuits too..will they include calculus too?

user218912

6:51 PM

yes.

user218912

you will need to know calculus for that.

user218912

read this

@iceL 1 or 2

user218912

amazon.com/Calculus-Early-Transcendentals-James-Stewart/dp/…

user218912

@Obliv 3

6:52 PM

okay that's 1 mod 2

thx

omg im trying to learn-1)programming 2)photoshop 3)basic electronics and going to school at the same time and now i gotta go back to basketball coaching(2 hrs everyday) too...and at home i gotta learn stuff(school related) too cuz gotta get ood grades

BUSY

user218912

inb4 0celo7 says I should read it too. xD