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/sci/ - Science & Math


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10374074 No.10374074 [Reply] [Original]

Ia there a way to find the elementary charge theoretically?

The current value is "measured" experimentally, ia there a way to find it theoretically?

>> No.10374215

What do you mean? Electric charge or all charges? Either way it's always multiples of 1/3, or 1.

>> No.10374231

There are grand unified theories which can explain the value of charge yes

>> No.10374242

>>10374215
the elementary charge [math]e=\sqrt(\frac{2h\alpha}{(\mu.C)})[/math]

1.6 Coulomb

>>10374231
Sorry, I didn't explain my question clearly, we got the value of the elementary charge from the millikan experiment, but is there a way to get it just from equations ?

>> No.10374245

>>10374242
In the standard model it is an observable and not directly given by maths itself. But as I said there are theories that explain the quantization and the value of e

>> No.10374252

>>10374245
>But as I said there are theories that explain the quantization and the value of e
like ?

>> No.10374272

>>10374252
Google grand unified theories there are plenty

>> No.10374317

>>10374242
No, the elementary charge is 1. You are talking about the definition of C, which is defined in terms of the definition of seconds and amperes, which is defined ib terms ofmeters, both if which are arbitrary.

>> No.10374340

>>10374317
>No, the elementary charge is 1
wtf are you about ?

https://www.bipm.org/utils/en/pdf/CGPM/Draft-Resolution-A-EN.pdf

>> No.10374374

>>10374340
What exactly do you want? Units are arbitrary, no there's not a way to derive it.

>> No.10374560

>>10374374
>Units are arbitrary, no there's not a way to derive it.
kek, dude honestly wtf are you talking about

>> No.10374585

>>10374560
You think we can somehow derive how long a metre is from theory? The elemental charge in C is dependent on how long a metre is.

>> No.10374612

>>10374074
Do you mean shit like Kaluza-Klein theory where the direction of motion along the hidden dimensions govern the effect we call charge in our 3-dimensional perception? Then yeah there is a theory put there to calvulate the unit charge, it just yields a very wrong result.

>> No.10374622

>>10374242
[eqn] e = \sqrt {\left. \frac{2 h \alpha}{\mu _0 c} \right.}\approx 1.602 \times 10^{-19} \space Coulombs \tag{1}[/eqn]
Where [math]e[/math] is the elementary charge.
[math]h[/math] is Planck constant.
[math]\alpha[/math] is fine-structure constant.
[math]\mu _0[/math] magnetic permeability of free space.
[math]c[/math] is the speed of light in free space.

How was this first derived? Does this have some importance, meaning or is just a trick with the other definitions?

Because:
[eqn]\epsilon _0 \mu _0 = \frac{1}{c^2} \tag{2}[/eqn]
[eqn]\alpha = \frac{e^2}{2 \epsilon _0 h c}\tag{3}[/eqn]

And if [math](1)[/math] is just manipulation of [math](2)[/math] and [math](3)[/math] anyway i don't understand how are they first derived or why they are defined in that way.

>> No.10374629

>>10374074
Heim theory.

>> No.10374706

>>10374622
This is what I was looking for, so the only way to find it theoritically is by finding a proof for the fine-structure constant and the proof of the Vacuum permittivity

>> No.10374779

>>10374706
Didn't you notice that i have more questions than you? Sorry would like to know more about this

>> No.10374808

>>10374779
you posted a better explanation of the question

>> No.10374845

>>10374560
You can adjust units to get any value you want. Only unitless quantities are fundamental.

Think a little harder.

>> No.10374896

>>10374622
>How was that first derived
In QFT a group of veriables that is unitless was found in a lot of places, so they defined it as the fine structure constant. That formula for e is just the formula of the fine structure constant rewritten to get e. So it's not realy derived, it's more just defined that way for convenience.

>> No.10374921

>>10374896
Also, we currently have no theory why the fine structure constant is what it is, (since it's dimentionless it's value can't be set to 1 like e), finding a theory that can explain the value of alpha is ongoing.

>> No.10374937

>>10374921
>it's value
>it is value
Retard.

>> No.10374947

>>10374252
String theory

>> No.10374972

>>10374947
>String theory
Fuck off, kaku >>>/x/

>> No.10374980

>>10374074
right now, no. the standard model needs some 26 constants (exact number might differ depending how you wish to count them) and they can only be obtained from experiments, that is, by asking nature how it works.

it is a hope that grand unified theories, or theories of everything, would give those automatically out of physical principles or out of just a few other quantities, but right now no GUT is any better than the standard model.

>> No.10374991

>>10374980
can't it be found just by providing a proof for the fine-structure constant ?

I think I saw a proof the other day by Dr. Atiyah

>> No.10375391

>>10374896
Thanks, well explained

>> No.10375398

>>10374980
This just a hunch, so send me off to /x/ now if you wish, but I have a strong suspicion that no theory of everything will ever be found because there just isn't any such thing.

>> No.10375717

>>10375398
that's a perfectly valid point. many physicists think like that. some that dont, work with guts.

>>10374991
atiyah has gone mad for many years. he thinks he is fine, but he is crazy. few people want to say that to his face and the ones who do, make atiyah go nuts with conspiracy theories that people are trying to suppress his very "important" work.
for the past years he has made big claims but his "discoveries" are just insane. it's a sad situation.

i mean was, everything above is in the past, since he's dead. you cant derive physics constants from math.

>> No.10375773

>>10374585
Well we can define a meter exactly from universal constants.

He’s clearly asking why is e the value it is, can it be explained to be the value it is, like the electron g factor is.
The answer currently is no, there are some hypothetical theories that do but they’re unconfirmed

>> No.10376017

>>10375773
The g factor is dimentionless, e isnt. And I don't know what you are smoking but there's no theories that can derive e. No one is even trying to derive e. And yes, we can define a metre, but not derive it. If you are asking why e has this specific value in our units, then the question reduces to why is 1kg equal to 1kg, 1s equal to 1s, and 1m equal to 1m. If were starting with those 3 definitions, sure, we can derive the value of e by just solving the electrostatics problem used to define a Colomb.

>>10374980
e is not even one of the parameters of the standard model, because it's 1.

>> No.10376242
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10376242

>>10376017
>e is not even one of the parameters

>> No.10376279

>>10374622
I'm brainlet, what is ε(0)?

>> No.10376294

>>10374560
>>10374585 is correct. Units are arbitrary in the sense that if you trace them back far enough, all the SI units were just stuff that we decided were good definitions for length, mass, etc. How is elementary charge any different? We can describe a model that proves the elementary charge exists, but depending on what unit we give it that value will take on any number dependent on the origins of that unit.

>> No.10376310

>>10374074
are there particles bonding these quarks, or are they naturally attracted to each other?

>> No.10376722

>>10376310
the gauge boson of the strong force is called a gluon

>> No.10376724

>>10376242
I don't know if you are trying to imply I'm wrong, because it's easy to check that it isn't.

>> No.10376731

>>10376722
gluons hold quarks together

>> No.10376736

>>10376731
gluons are 8 almost identical elementary particles that convey the strong force.