If there’s anyone who can, please let me know if the similarities between these two formulas imply a relationship between gravity and electrical attraction or hint at a unified theory, or if it’s just a coincidence or a consequence of something else.
The relation between them is that they’re both forces that scale with the inverse square of the distance between the objects. Any force that scales with the inverse square of distance has pretty much the same general form.
Another similarity is that both are incomplete, first approximations that describe their respective forces. The more complete versions are Maxwell’s laws for electromagnetism and General Relativity for gravity.
There is one thing particularly interesting, and that is that the inverse square laws appears again. It appears in the electrical laws for instance.
That is electricity also exerts forces inverse to the square of distance with charges. One thinks perhaps inverse square distance has some deep significance, maybe gravity and electricity are different aspects of the same thing
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Today our theory of physics, laws of physics are a multitude of different parts and pieces that don’t fit together very well. We don’t understand the one in terms of the other. We don’t have one structure that it’s all deduced we have several pieces that don’t quite fit yet.
And that’s the reason in these lectures instead of telling you what the law of physics is I talk about the things that’s common in the various laws because we don’t understand the connection between them.
But what’s very strange is that there is certain things that’s the same in both
Richard Feynman and 45:48 https://youtu.be/-kFOXP026eE?si=hAIvDhWVGxMOvEi1
Electromagnetism and gravity are both mediated by massless bosons; photons and gravitons respectively. This is why both forces follow the inverse square law.
I don’t think there’s any evidence for gravitons yet, and gravity hasn’t been quantized. I’d say it’s this similarity that’s the best argument of quantum gravity, not the other way around.
Fair. The masslessness of the bosons that should mediate gravity, along with them being spin-2, can however be deduced from the properties of gravitational waves.
We know that gravity is a wave that travels at the speed of light, this has been experimentally measured many times. If it is also quantized (a very reasonable
symptomhypothesis since everything else that we’ve ever seen is) then by definition there are particles that carry gravity.If gravity is continuous then we would end up with something like the ultraviolet catastrophe but for gravity.
Hmm, I hadn’t considered an “ultragravity catastrophe”. I wonder if this could accout for dark energy or the supposed inflatons? Probably not, the catastrophe suggests infinite energy, not just lots of energy, eh?
The ultraviolet catastrophe was averted due to the discreet nature of electrons though, and I don’t recall gravity behaving as a blackbody radiator anyway. Would this come into effect at horizons?
Sorry, I think I came off as too confident in my previous comment. I’m quite sure about my first paragraph but the rest is just speculation from an amateur.
If I would risk speculating even further though, there’s some similarity in the sense that infinities indicate a problem. In the ultraviolet catastrophe the infinity arises from the energy of arbitrarily short EM wavelengths. With gravity it arises in the density of black holes. It seems unreasonable that it would actually be infinite, and it’s possible that quantization of gravity plays a part in preventing that from happening.
I don’t understand the formula, but I understand Mr. Bean. +1
If you have two charges
q1andq2, you can get the force between themFby multiplying them with the coulomb constantK(approximately 9 × 10^9) and then dividing that by the distance between them squaredr^2.q1andq2cannot be negative. Sometimes you’ll not be given a charge, and instead the problem will tell you that you have a proton or electron, both of them have the same charge (1.6 × 10^-19 C), but electrons have a negative charge.q1 and q2 can be negative. The force is the same as if they were positive because -1 x -1 = 1
In this case yes, but if q1 was -20μC, q2 was 30μC, and r was 0.5m, then using -20μC as it is would make F equal to -21.6N which is just 21.6N of attraction force between the two charges.
If they are oppositely charged particles, I would expect that there is a force of attraction acting on them, yes.
I am not saying that’s wrong, just that there’s 21.6N of attraction force between the two charges not -21.6N.
But those are the same thing.
No, if the force is negative it acts in the opposite direction
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.
It’s electromagnetism you mean, not quantum mechanics.
Guess what electromagnetism turned out to be
They’re different things. The OP means electromagnetism, Coulomb’s law has nothing to do with quantum mechanics, it’s classical physics.
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.
“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.
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.
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.
The inverse stare law.
