How Special Relativity Makes Magnets Work

This problem has been haunting my mind since I read the concepts of physics part - 1 with the diagram of lorrentz force by a linear conductor on a moving electron. No one (teachers & professors) ever answered the question where did that force go in the charge’s frame of reference. The closest I got was equivalent E field getting created, which can be calculated by lorrentz transform which requires more physics 🫤. 😃Thank you so much, I can sleep peacefully now 😃. P.S: another mystery similarly handwaived has been ‘gyroscopic stability’ which is the explanation of balance of the wheel on one side experiment, spinning tops, bikes etc. Is there a better/intuitive explanation without the vector formulation of L?

I think this entire thing is a misconception. The actual speed of electrons in the wire is something like 1mm/sec. This is absolutely insignificant in terms of any possible relativistic effect. Also, if instead of the moving charge "cat", you place a stationary magnet next to the wire, the magnet will also experience a force due to the electromagnetic field generated by the current. Again, this cannot be explained as a relativistic effect because the speeds involved are near-zero. It is absolutely true that there are relativistic electromagnetic effects when moving in high speeds, but I think the video conflates those with the electromagnetic field generated by a current carrying stationary wire.

Why are you bringing the length contraction and stuff into this? I mean.. When the positively charged moving cat has the same velocity as the electrons, so in its frame of reference it is stationary with respect to electrons but the protons in the wire are moving with respect to it with same speed in the opposite direction so the positively charged cat is repelled by the MAGNETIC FIELD of those moving protons. So, its the magnetic field that's into action in both frame of references, just from different particles.. (In observers case the Magnetic field from electrons interact with magnetic field of the cat and repels it, while in the cat's frame of reference it's the Magnetic field from protons (moving with same speed in opposite direction) in the wire that interacts with the magnetic field of cat and repels it)

then why wouldn't the cat start rotating around the wire along with the "magnetic" field lines

During a propagation of electromagnetic waves in the vacuum, how electric and magnetic fields can interact together to create a propagating wave if the magnetic field is merely a relativistic effect of an electric field from a putative different frame of reference ????

Since the drift velocity of the electrons is so small (a snail's pace) in the cat's frame of reference, how can relativistic length contraction have any noticeable effect??
THANKS FOR SUCH A THOUGHT PROVOKING VIDEO!!

For the stationary cat the electrons are moving. Hence, they get more dense. Hence, the car should get attached.

If the density of the moving electrons is somehow magically matching the density of the protons then turning off the current should repel the stationary cat.

Ask videos so far on this matter seem to make the exact same error: applying the survival relativity only in the case of the moving outside charge but not too the stationary one.

?? An object moving relative to me takes up less space then standing still???

What would happen to the positively charged cat if we replaced "the wire full of stationary protons and moving electrons", with only "one moving electron", or with "a handful of moving electrons"?

Magnetism is also generated by electron (or other charged particle) spin.

Why don't electrons contract in your frame of reference, when they start moving? 🤔
Also, in cat's frame of reference, moving positive charges is a current, so why doesn't this current create magnetic force?

So, is this video an explanation of 'The electrodynamics of moving bodies' per the title of Einstein's original paper?

I first watched this when I was twelve. Finally understood it now that I’m 21.

ÕMĞ é PôWéŘ-PhÛľĽ Orrrsé-Strâylêan
😟😟😟😰😩😰😟😟😰😩😩😧😧😦😧😦😧😳😳😵😶😵😳

Isnt the stationary cat also supposed to experience force? A pulling force? Cuz to it the electrons appear moving and their gaps are shrinked whereas the positive charges arent so they appear more distanced to each other...eventually increasing the negative charge density resulting a pull for the cat?

But from your point of view if the electrons are moving then they are contracting and taking up less space so the cat should be attracted?

Is there for sure true? I’ve never heard this explanation of electromagnetism… that its caused by length contraction. But wait… how would only the negative charges get contracted in the wire but not the positive ones. Wouldn’t they both contract since they are both present in the same wire?

I feel crazy saying this given the credibility that both Veritasium and Minute Physics have, but there feels something a bit too conveniently simple about this explanation.

I need sources on this ugh

But when the cat is stationary the electrons are moving w.r.t it so electrons saperation must get contracted. Hence the wire now should be slightly negatively charged and the Cat should get attracted to it instead of experiencing no force.🤔🤔

Wow

bruh , my life was a lie .

question if the positives are viewed as bigger while stationary does that mean they are physically bigger and take up for my space bc how does size change in a short amount of time or with no catalyst besides time and speed or is speed the catalyst becase length and time arent absolute

Actually the explanation is not clear at all.

Wooooaaaaahh. So spacetime dilation makes particles actually smush together relative to another particles frame of reference therefor imbalancing the charge only to it??? That's absolutely bonkers. I mean it makes sense. But like. Wow.

At the request of a friend who is at their house, I will now pedantically shred the most minute details. For starters, you said that a magnetic field is caused by an electric field in a different frame of reference. But, that implies ontologically all magnetic fields are a result of an electric field of a different frame. In special relativity, all frames are equal. Rather, the electric and magnetic field are all a part of the electromagnetic field tensor which leads to a different relative of a magnetic field. Thus, so as an electric field can induce the appearance of a magnetic field in a different frame, a magnetic field can induce the appearance of an electric field in a different frame. I also want to make note of the fact that it is misleading to say an electromagnet is an example of special relativity in action. Just because we understand the operation of a device using different theories does not mean in itself is a result of that theory. Indeed, it would be just as misleading to argue for general relativity purely on the fact that it can describe gravitational motion. Rather, it is by other principles of physics and experimental discovery that we find these theories to be accurate. In particular, this result is entirely based on assuming the principle of relativity holds or that there is no other physical entity that can account for the different of a field: in particular, we would have this the magnetic field before. If, as physicist before 1905 thought, that there was an ether field that, like sound acts as a disturbance in air, so too an electromagnetic field is a disturbance in ether. In this context, electromagnetic theory could hold but would not be the same to all frames, only an ether rest frame. A relative motion would induce a relative velocity of the ether to add into the law. There is no implicit disagreeance of electromagnetic theory with galilean relativity, other than by experiment. Thus, there is no reason to mislead: special relativity is not in itself needed to make an electromagnet work. We must not forget the real history of electromagnetism.

Sincerely, Sarah.

The cat doesn't actually have to move at all if there's a current through the wire. If the cat moves as well, then, depending on direction relative to current, will affect the force.

But if the electrons are moving when the cat is stationary why dont they contract and seem more dense? Then there should be a force of attraction between the cat and the wire?

But, as magnetic compass is in rest how can it be affected by magnetism here(deflects)

Note that this is only valid as long as you are using light as your measurement device.
Using only mechanical devices, you'll have to apply Newton, instead.

Nice

Came after recommendation from Shrivendu Sir (AirBatch ). PW 😂

So, According to relatively in photons frame I am traveling at speed of light and doing travel.
Is this makes sense 🤔?

Special Relativity doesnt make magnets work. Electrical magnetism makes that work. Poles. Propaganda machines on this channel. Halton Arpe busted this theory and that of redshift along with Anthony Peratt

Navel cat

The truth about the insane relativistic stuff that the current vicious educational system and its fans imposed in our schools and the consequences that our societies are suffering right now:
The absurdity of special relativity theory: /JxzhoSWBtgw Non-Euclidean Geometry Myths Busted: /p4tW6onBVmg How to Escape the Matrix: /jM9KZjgnujA

Really? The electrodes move really slow so there is no significant effect from this. And anyway there is no need to invoke effects from the special relativity since it is just Maxwells equations. What happened was that Maxwell only thought about electromagnetism as something standing on a table not something wishing around in space. So nobody knew how to handle this, except Einstein that really only said shut up and calculate ( hmm sounds familiar, but that is for another time).

Einstein too wrote in his 1905 paper: “the force acting on a body in motion in a magnetic field is nothing else but an electric field”

This explanation is orgasmic,
My dopamine, adrenaline everything is all time HIGH!
Can't thank you enough❤

The video I needed that I didn't know I needed.

you should have used the fact that from the cat perspective the whole wire is moving to the left not just the protons!

when the cat is stationary and the electrons are moving to the right, why electrons don't have a higher spatial charge density than the protons due to length contraction, causing an attractive force on the cat? Since you are explaining the repulsive force in case of moving cat (from the cat perspective) as: protons are moving to the left, electrons and the cat are both stationary, which is the same scenario from our perspective when the cat is stationary and electrons are moving to the right.

Could length contraction diminish distances in deep space travel ?

This still doesn't explain how magnets work. In all my study no one has ever really explained how or why magnets work but the electric part sure. I've been knowing that part for a long time but why do electrons create a magnetic field or is it even the electrons doing it. What really is an magnetic field? It's completely a mystery at it's core. I mean to even be a field it has to exist in three dimensions right at all times so it's everywhere all at once.

Finally

Mind blown.

If you'll pardon the expression - using Relativity to explain magnetism is - a stretch. In actuality - physicists CANNOT explain magnetism's MECHANICAL action. Can't explain gravity, either - just Einsteinian nonsense about curving space - which makes thing "follow" along that curve - without actually explaining WHY "things" "want" to "follow" that curve. sheesh

If you are wondering why moving electrons do not cause length contraction when the cat is stationary, electrons are little more complicated than simple pictures of protons. Free electrons in metal, that's what they make a conductor, are nevery stationary at room temperature. They actually constantly move really fast (~ 1 million m/s) and are scattered off by protons and other electrons. Without electric field, they move to all different direction and that's why we don't see any effect. When electric field is applied, their moving directions are slightly drifted and their overall collective motion becomes what we call "current". It's not like they all of a sudden align and start marching in a single direction altogether. Therefore, you cannot simply apply special relativity to those electrons.
For protons, however, they are mostly tightly bound to the lattice structure. Thus, they are stationary and we do observe length contraction when the observer moves fast and that creates net nonzero electric fields as this video explains.

P.S 1: electron contraction is not something you would consider under any circumstances. When you try to measure the contraction of an electron, uncertaintly principle dominates and you lose the idea of how fast the electron is. Thus what's the speed to compute the contraction?

P.S. 2: If electron's size is macroscopic and they are all aligned in a single direction, both their size and the spacing get contracted.

Here's a paper of someone trying to apply this idea to suggest that gravity is a "2nd order relatvistic effect" of the electric force. I don't buy into it, but i thoug I'd share