this post was submitted on 05 Nov 2023
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[–] jimmydoreisalefty@lemmus.org 39 points 1 year ago* (last edited 1 year ago) (12 children)

edit: fix similarities typo

Awesome to see the similarities between: Newtonian Mechanics and Quantum mechanics

Coulomb's law was essential to the development of the theory of electromagnetism and maybe even its starting point, as it allowed meaningful discussions of the amount of electric charge in a particle.

Here, ke is a constant, q1 and q2 are the quantit>ies of each charge, and the scalar r is the distance between the charges.

Being an inverse-square law, the law is similar to Isaac Newton's inverse-square law of universal gravitation, but gravitational forces always make things attract, while electrostatic forces make charges attract or repel. Also, gravitational forces are much weaker than electrostatic forces. Coulomb's law can be used to derive Gauss's law, and vice versa. In the case of a single point charge at rest, the two laws are equivalent, expressing the same physical law in different ways. The law has been tested extensively, and observations have upheld the law on the scale from 10−16 m to 108 m.

[–] Claidheamh 24 points 1 year ago (1 children)

It's electromagnetism you mean, not quantum mechanics.

[–] photonic_sorcerer@lemmy.dbzer0.com -4 points 1 year ago (1 children)

Guess what electromagnetism turned out to be

[–] Claidheamh 20 points 1 year ago (2 children)

They're different things. The OP means electromagnetism, Coulomb's law has nothing to do with quantum mechanics, it's classical physics.

[–] Natanael -3 points 1 year ago

Quantum electrodynamics though

[–] photonic_sorcerer@lemmy.dbzer0.com -5 points 1 year ago (2 children)

Okay but tell me, what theory superceded electromagnetism?

Sure, EM is still useful, I use it in my work, but in the end, it all boils down to QM.

[–] scubbo@lemmy.ml 12 points 1 year ago (1 children)

"X depends on or is built up on Y" does not imply "X is Y". Concepts, laws, techniques, etc. can depend or be higher-order expressions of QM without being QM. If you started asking a QM scientist about tensile strength or the Mohs scale they would (rightly) be confused.

[–] photonic_sorcerer@lemmy.dbzer0.com -1 points 1 year ago (2 children)

Yes, of course. Coloumb and Maxwell had no idea about QM when they were developing their ideas. Not to mention that these higher-order abstractions are just as valid as QM (up to a point, but so is QM). Depening on the application, you'd want to use a different abstraction. EM is perfect for everyday use, as well as all the way down to the microscale.

My point is that EM is explained by QM, and therefore supercedes it. You could use QM to solve every EM problem, it'd just be waaaaay too difficult to be practical.

[–] scubbo@lemmy.ml 6 points 1 year ago

I feel like you're using "supercede" differently to the rest of us. You're getting a hostile reaction because it sounded like you're saying that EM is no longer at all useful because it has been obsoleted (superceded) by QM. Now you're (correctly) saying that EM is still useful within its domain, but continuing to say that QM supercedes it. To me, at least, that's a contradiction. QM extends EM, but does not supercede it. If EM were supercedes, there would be no situation in which it was useful.

[–] SuckMyWang@lemmy.world 3 points 1 year ago* (last edited 1 year ago)

Guys guys, yesterday I ate some hot wings and then shit myself on the way to the toilet 🤣💪💯

Also can you really solve all em equations with qm? I always thought the laws broke down from one to the other? So you’re saying going from em to qm the laws break down but going from qm to em the laws hold up?

[–] Claidheamh 6 points 1 year ago* (last edited 1 year ago) (1 children)

Quantum mechanics didn't supersede electromagnetism. Again, they're different things. Electromagnetism is a fundamental interaction. Whereas quantum mechanics describes the mechanics of quantum particles. Whether those particles are affected by electromagnetic forces or not. It's a description of how they behave at quantum scales.

Coulomb's law has nothing to do with quantum mechanics, it's a description of how macroscopic charged particles interact. What the OP should have said to be correct is:

Awesome to see the similarities between: Newton's law of gravitation and Coulomb's law

I don't know where he got quantum mechanics from.

[–] photonic_sorcerer@lemmy.dbzer0.com 0 points 1 year ago (1 children)

Bro EM is not fundamental. Neither is QM, but it's the closest we've got to fundamental forces. You can derive EM from QM.

Coloumb's law and Maxwell's equations are classical mechanics, meaning they work well enough for everything you can see around you. The smaller you go, the less accurate EM becomes. That's why you can't design a chip or microsensors or whatever with knowledge of EM alone.

What do you think the mechanics of quantum paryicles are? All their interactions. That includes what turns out to be EM.

This doesn't invalidate EM. EM is great! It explains so much about our world. But not everything. QM gets close, and because you can derive EM with it, QM supercedes it.

[–] Claidheamh 1 points 1 year ago

There's a surface level misunderstanding of the concepts going on.

Once again, let me try to clarify what I think you're not getting. Quantum mechanics is exactly that, mechanics of particles. Just like Newtonian mechanics, but for quantum particles instead of macroscopic. The same way in classical physics you use Newton's laws to describe the motion of charged (or any, really) particles, in modern physics you use quantum mechanics. It doesn't "replace" electromagnetism, they're separate things. A bad metaphor, but it's a little like saying cardiology replaces anatomy.

Yes, electromagnetism is fundamental. No, you can't derive it from quantum mechanics — you'd use quantum field theory for that (specifically quantum electrodynamics).

Coulomb's law and Maxwell's equations are classical physics, but not mechanics. They don't describe the motion of particles, they describe forces and fields. And you use them all the time in quantum mechanics. Pick up any intro to quantum physics textbook, and you'll see them everywhere.

All that to say again that this meme is comparing Newton's law of gravitation with Coulomb's law... So why keep insisting on bringing quantum mechanics into this? It really doesn't figure into the meme at all.

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