1. When I was in school I was taught that light and all other major forces where all related and referred to EMF. My question is, does gravity, magnetism and electricity all travel at the speed of light? Even if the answer is no, the effect of the force, like water in a pressurized hose doesn't really need to travel at all to display it's effect at the spigot, just open the valve at the end and the applied potential is released faster the the speed of light....correct?

2.

3. I don't believe any of the fundamental forces travel faster than light speed, because we refer to light speed as the absolute fastest speed possible. If one of the other forces was faster, we'd use that term as the absolute fastest possible speed in the Universe.

I have no idea how fast a magnetic field propagates, but from what I understand, electrons have a very slight amount of mass (about 1/1,000th the mass of a proton or something?) and so if electrons are the force carrier of the magnetic field, I believe magnets wouldn't work as fast as light speed.

I'm not sure, but I thought it had been experimentally verified that gravity travels at the same speed as light.

4. Originally Posted by keeseguy
Even if the answer is no, the effect of the force, like water in a pressurized hose doesn't really need to travel at all to display it's effect at the spigot, just open the valve at the end and the applied potential is released faster the the speed of light....correct?
Incorrect. Despite popular thinking to the contrary, water is compressible. The movement of water when you turn on the tap can only move forward at the speed of sound in the material - considerably slower than the speed of light.

5. Originally Posted by Daecon
I don't believe any of the fundamental forces travel faster than light speed, because we refer to light speed as the absolute fastest speed possible. If one of the other forces was faster, we'd use that term as the absolute fastest possible speed in the Universe.

I have no idea how fast a magnetic field propagates, but from what I understand, electrons have a very slight amount of mass (about 1/1,000th the mass of a proton or something?) and so if electrons are the force carrier of the magnetic field, I believe magnets wouldn't work as fast as light speed.

I'm not sure, but I thought it had been experimentally verified that gravity travels at the same speed as light.
While I agree that electrons are very useful in producing magnetic fields the force carrier for electromagnetism is photons.
In quantum physics, the electromagnetic field is quantized and electromagnetic interactions result from the exchange of photons.

As far as the speed of light goes, that's only measured through the medium of our universe. If we are ever able to find an outside of the universe into a different medium then maybe that speed will be different. (I'm not holding my breath)

6. Originally Posted by Bad Robot
While I agree that electrons are very useful in producing magnetic fields the force carrier for electromagnetism is photons.
In quantum physics, the electromagnetic field is quantized and electromagnetic interactions result from the exchange of photons.
Ah, I didn't know that. Thanks for the clarification.

So then magnets do work at light speed, I take it?

7. Originally Posted by Daecon
While I agree that electrons are very useful in producing magnetic fields the force carrier for electromagnetism is photons.
In quantum physics, the electromagnetic field is quantized and electromagnetic interactions result from the exchange of photons.
Ah, I didn't know that. Thanks for the clarification.

So then magnets do work at light speed, I take it?
I'm not clear about what you are asking. I think you want to know how fast a magnetic field forms to it's limits when conditions for the magnetic field are formed. I don't really know and I'm not sure the photon force carrier can be applied for that determination.

8. Originally Posted by Bad Robot
Originally Posted by Daecon
While I agree that electrons are very useful in producing magnetic fields the force carrier for electromagnetism is photons.
In quantum physics, the electromagnetic field is quantized and electromagnetic interactions result from the exchange of photons.
Ah, I didn't know that. Thanks for the clarification.

So then magnets do work at light speed, I take it?
I'm not clear about what you are asking. I think you want to know how fast a magnetic field forms to it's limits when conditions for the magnetic field are formed. I don't really know and I'm not sure the photon force carrier can be applied for that determination.
Sorry, I meant that the magnetic force travels at light speed. If you had a magnet exactly 299,792,458 metres away from a metallic object, that object wouldn't feel any magnetic influence until after exactly 1 second had passed.

9. Originally Posted by Daecon
Originally Posted by Daecon
While I agree that electrons are very useful in producing magnetic fields the force carrier for electromagnetism is photons.
In quantum physics, the electromagnetic field is quantized and electromagnetic interactions result from the exchange of photons.
Ah, I didn't know that. Thanks for the clarification.

So then magnets do work at light speed, I take it?
I'm not clear about what you are asking. I think you want to know how fast a magnetic field forms to it's limits when conditions for the magnetic field are formed. I don't really know and I'm not sure the photon force carrier can be applied for that determination.
Sorry, I meant that the magnetic force travels at light speed. If you had a magnet exactly 299,792,458 metres away from a metallic object, that object wouldn't feel any magnetic influence until after exactly 1 second had passed.
Anything that could put out a magnetic force that would affect a metallic object at that distance would already have a magnetic field in place and there would be no need to wait any time at all. But an electric magnet can be turned on and off and the magnetic field is generated when electricity passes through a coiled wire. I believe that as soon as the wire has flowing electrons the magnetic field will propagate to it's limit at light speed.

10. so what I learned many years ago is not far from correct, The electron doesn't necessarily travel at the speed of light through the wire, but the bump effect of electron flow does...not the electron, only the effect? At the risk of seeming uneducated I will now ask, gravities effect on light must implicate that gravity must also have some light speed related influence?

11. Originally Posted by keeseguy
so what I learned many years ago is not far from correct, The electron doesn't necessarily travel at the speed of light through the wire, but the bump effect of electron flow does...not the electron, only the effect? At the risk of seeming uneducated I will now ask, gravities effect on light must implicate that gravity must also have some light speed related influence?
The affect of gravity is from warped space and when light passes through that warped area of space it bends a little as if it were passing through a convex lens. An example of that effect is light passing through a magnifying glass. It is sometimes referred to as a lensing effect. The gravitational affect on light has nothing to do with the speed of light. However there is gravitational red and blue shifting of the light. This affect is mostly negated as when light leaves a galaxy it's red shifted and then as it enters our galaxy it's blue shifted for a near zero net effect.

12. Originally Posted by keeseguy
so what I learned many years ago is not far from correct, The electron doesn't necessarily travel at the speed of light through the wire...
Not only does it not "necessarily travel at the speed of light" in a wire, it typically does not even travel as fast as a human crawls. Electron drift velocity in conductors is a tiny fraction of c under the conditions we normally encounter, which tells us that we should not confuse drift velocity with the speed with which an influence propagates.

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