4 ms·
It's that 'spooky action at a distance' thing. It's still never been clear to me but what's the speed of Electromagnetism (i.e. if you drop a highly magnetic o
by AdamN 2y ago
It's that 'spooky action at a distance' thing. It's still never been clear to me but what's the speed of Electromagnetism (i.e. if you drop a highly magnetic object into an area - how quickly is the force impacting the distant surroundings)?
- n_plus_1_acc 2y agoElectromagnetic waves travel at the speed of light
- rwmj 2y agoBecause they literally are light.
- arbitrage 2y agoNo, light is EM radiation. Not all EM is light.
- setopt 2y agoIsn’t that distinction more philosophical than not? Like the Feynman diagram is in any case that a photon is transmitted between two charged objects, whether that photon is “real” or “virtual”. I know there are physicists who interpret this as there being two distinct things, either particle-like excitations (photons) and more general excitations (not photons). These usually don’t think of Feynman diagrams as representing anything real. But I also know there are some physicists who consider virtual photons “real”. And in that picture of reality, all EM interaction is “light”.
- fooker 2y agoThe speed limit of any information in the universe is the same, as far as we know. There are effects like quantum entanglement that seemingly bypasses this, but there is no way to extract useful information out of it.
- staplers 2y agothere is no way to extract useful information out of it Not yet
- ithkuil 2y agoThe propagation of the change in the magnetic field travels at the speed of light. The act of moving a magnet and thus changing the magnetic field at one point also induces a change in the electric field and vice versa, that's why you'll always hear talking about "electromagnetic" waves (which light, radio waves, etc are an instance of). To make things even more interesting there is also this phenomenon: the magnetic field is created by moving electric changes, relative to the observer. If an observer moves at the same velocity as the electric charge it will not observe a magnetic field. It turns out that when you apply special relativity to the effects of electrical charges (coulomb 's law) you get a theory of electro-magnetism (Maxwell's equations). Magnetism this "follows" from the behavior of electrical fields and special relativity. That doesn't make magnetism less "real" but it hints at the intimate connection that the two forces have and what we now talk about them as "electromagnetism"
- ithkuil 2y agoTo add to other comments here: think about what happens when a heavy object (e.g. a planet or a moon) moves, how quickly does the change to the gravitational field propagate to affect the distant surroundings? Answer; at the speed of light.