The h Bar

4:10 AM

ㅤ

vzn

@JackRod liked it too, thx for sharing! oh, they didnt say anything about fluid dynamics even though its very eminent... :o

4:56 AM

Hi Guys...

Gabriela Da Silva

6:49 AM

Someone online?

I guess

Jack Rod

@RewCie listening to a good song

@JackRod which one?

Gabriela Da Silva

I was thinking about entropy, is claimed that the universe entropy increases in irreversible process, but to say this is necessary to adopt the universe model as an isolate thermally universe?

Marshmello & Anne-Marie - FRIENDS [Alternative Music Video]

$dS \geq 0$

Jack Rod

6:54 AM

►

@RewCie

@JackRod already heard it...

Jack Rod

I can relate it

9:34 AM

Does total charge conserved?

In case if we charge two different capacitors separately at different voltages. And then attached to series/parallel combination.

What about specially series combination. It shows some problem in this case. Not showing same charge on each capacitor?

@JohnRennie sir, @ACuriousMind pls help me to figure out this above condition.

10:18 AM

Charges is not conserved in series combination. Why???

10:29 AM

I found one site of 'Trapped Charge" concept if charge before connect in series. But no detail there it is paper I don't have access.

@123 I have no idea what you mean when you say "charge is not conserved", or what it has to do with the series combination.

Two capacitors charge separately with batteries q1 = 10micro f, V1 = 600v and q2 = 20microf, V2 = 1000v. 1000v then disconnected. They are then joined in series.

Pls solve these @ACuriousMind it does not show that charge is conserved. It shows less than total charge. Which was before.

Total charge = 2.6x10^-2 C before placed in series. After series it shows Total charge = 2.1334x10^-2C

In question where I wrote problem q1 and q2 has capacitance C1 & C2 for charges

11:10 AM

@123 But the charge on a capacitor is never "conserved" if you just look at the charges of all capacitors in a circuit. If you just charge a capacitor from a voltage source, it starts at zero net charge and ends up at some finite charge

clearly, charge has changed (the additional charge in this case came from the voltage source/the wires, so the total charge of the universe is still conserved)

11:29 AM

But the same in parallel combination charge became conserved.

11:40 AM

so what?

capacitors behave differently in series than in parallel, like most other electrical components

it's not "charge conservation" that causes their behavior in parallel, but that putting them in parallel essentially is the same as just having one big capacitor with the capacitance of both, so there's no reason for the total charge on them to change

Jamiec

11:55 AM

Hi Physics people. I'm a mod on Aviation.SE and we occasionally get questions which are about wings - but not of the aircraft variety. It's a bit of an edge case for us. We might be able to answer it, but officially it is off topic. An example is here.

If this sort of question were migrated to Physics do you think it would be well received by your community, closed, or even migrated to Aviation as "looks like a wing, must be aviation related"?

skullpatrol

I feel that it will not be well received by the community; but, you could try.

@Jamiec In principle questions about aerodynamics/hydrodynamics (or whatever else might be "wing-related") are on-topic here, but your particular example would be off-topic as engineering and/or homework-like, since it asks about a specific solution to a problem rather than about the physics behind it.

Captain Bohemian

@NiharKarve what on earth are these mass eigenstates? Is there such an operator Mass Operator?

Jamiec

@ACuriousMind Thank you

skullpatrol

12:14 PM

@Jamiec has the pandemic slowed the traffic on your site?

Jamiec

@skullpatrol yes

skullpatrol

any change in this should be interesting

Nihar Karve

@CaptainBohemian have you seen this?

Captain Bohemian

@NiharKarve not yet. let me read it then tell you my comment.

Captain Bohemian

1:34 PM

I have the impression of seeing the mass matrix in textbooks of classical mechanics but have never seen the term mass operator in quantum mechanics textooks. @NiharKarve

Slereah

The mass operator in non-relativistic QM is just $m \hat{I}$

Since mass is just a constant

fqq

In QFT/Poincaré group representations the mass operator is $P_\mu P^\mu$

but I don't think that's really needed for the question above or to understand neutrino oscillations. That's just about the 3x3 mass matrix, the coefficients of the quadratic term in the Lagrangian. It's there at the classical level

Nihar already linked to the correct answer, it's where the mass matrix in the Lagrangian is diagonal, it has nothing to do with any operator.

fqq

yes