You can slow the group velocity of light. Can you slow electricity?

In summary, there are various methods to slow down visible light, but most of these methods focus on slowing the group velocity rather than the phase velocity. The velocity of electromagnetic waves in a transmission line depends on the dielectric constant of the insulator materials used. While electricity in a wire may propagate at 2/3 the speed of light, the drift velocity of electrons is much slower. Research has shown that metamaterials can slow down electromagnetic waves at very low frequencies, but it is unclear if they can also slow down electricity without causing excessive resistance losses.
  • #1
cyber stealth
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There are various methods to slow and even stop visible light. Most of these methods appear to be slowing the group velocity of light, not the phase velocity.

Can you slow the velocity of propagation of electricity? I have seen estimates that electricity, in a wire, propagates at 2/3 the speed of light. The drift velocity of electrons in the wire may be one meter an hour, for DC current, but I am interested in the propagation speed of the electricity instead.
 
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  • #2
cyber stealth said:
There are various methods to slow and even stop visible light. Most of these methods appear to be slowing the group velocity of light, not the phase velocity.

Can you slow the velocity of propagation of electricity? I have seen estimates that electricity, in a wire, propagates at 2/3 the speed of light. The drift velocity of electrons in the wire may be one meter an hour, for DC current, but I am interested in the propagation speed of the electricity instead.

The velocity of the electromagnetic (EM) wave propagating down a transmission line cable depends on the dielectric constant of the insulator materials used in the cable. That's where you can see numbers like v = (2/3) c and similar.
 
  • #3
I have seen research showing metamaterials working on very-low-frequency electromagnetic waves, such as 60 hertz, and was wondering if metamaterials or other methods could be used to greatly slow electricity, without causing excessive resistance losses.

Light can be slowed down to less than one kilometer per second. Could electricity?
 

1. Can you really slow down the speed of light?

Yes, it is possible to slow down the group velocity of light in certain mediums. This is achieved by changing the refractive index of the medium, which affects the speed of light as it passes through.

2. How is this possible if light travels at a constant speed in a vacuum?

Light does travel at a constant speed of 299,792,458 meters per second in a vacuum. However, when light travels through a medium such as water or glass, it interacts with the atoms and molecules in the medium, slowing down its overall velocity.

3. Can you slow down the speed of electricity as well?

Yes, the speed of electricity can also be slowed down by altering the properties of the medium it travels through. This is known as the propagation speed of an electrical signal.

4. What are the practical applications of slowing down the group velocity of light and electricity?

Slowing down the speed of light and electricity can have a wide range of applications, such as in optical communication systems, fiber optics, and quantum computing. It can also be useful in controlling the speed of electrical signals in electronic devices.

5. Is there a limit to how slow you can make the group velocity of light and electricity?

Yes, there is a limit to how slow these velocities can be. According to Einstein's theory of relativity, the speed of light in a vacuum is the maximum possible speed in the universe. Therefore, the group velocity of light and electricity cannot be slowed down below this limit.

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