Speed of light, permeability and permitivity of free space

In summary: Zo, and c is related to εo and μo. See attachment for my text's explanation's on the permittivity and permeability of free space, if you want but it's not necessary. Anyway, after reading those explanations of the p & p of free space I'm having a very difficult time understanding why taking the inverse square root of the product of those equals the speed of light. Why? I guess it's one of those impossible brute facts that has no explanation such as why an electron absorbs a photon when it ascends to a higher energy level. In any case, I find that very bizarre.
  • #1
bobsmith76
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See attachment for my text's explanation's on the permittivity and permeability of free space, if you want but it's not necessary. Anyway, after reading those explanations of the p & p of free space I'm having a very difficult time understanding why taking the inverse square root of the product of those equals the speed of light. Why? I guess it's one of those impossible brute facts that has no explanation such as why an electron absorbs a photon when it ascends to a higher energy level. In any case, I find that very bizarre. The permeability of free space is related to the current, that is the number of electrons moving and the permittivity is related to Coloumb's constant plus the surface of a sphere. I don't see why those entities when multiplied then square rooted then inversed should equal the speed of light.
 

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  • #2
bobsmith76 said:
See attachment for my text's explanation's on the permittivity and permeability of free space, if you want but it's not necessary. Anyway, after reading those explanations of the p & p of free space I'm having a very difficult time understanding why taking the inverse square root of the product of those equals the speed of light. Why? I guess it's one of those impossible brute facts that has no explanation such as why an electron absorbs a photon when it ascends to a higher energy level. In any case, I find that very bizarre. The permeability of free space is related to the current, that is the number of electrons moving
No, the permeability is the constant that relates (in the example) the current to the strength of the magnetic field. In essence, it is the constant that determines the strength of a the field at any given distance from a magnetic pole.
and the permittivity is related to Coloumb's constant plus the surface of a sphere.
Again, Essentially, permittivity relates strength of Electrostatic field to charge.

Permeability and Permittivity are for magnetic and electric fields as the gravitational constant is to gravity.

I don't see why those entities when multiplied then square rooted then inversed should equal the speed of light.

A changing electric field produces a changing magnetic field and vice-versa. Light is basically oscillating electric and magnetic fields supported by this interaction between them. Since the permittivity and permeability of space determine how these fields interact, it also determines the propagation speed of the EM radiation. For a more detailed understanding, you would have to study the Maxwell equations.
 
  • #3
There are four constants that are closely related; the speed of light c, the permeability of free space μo, the permittivity of free space εo, and the impedance of free space Zo. Specifically,
[tex] Z_o= \left( \frac{\mu_o}{\epsilon_o} \right)^{1/2} ≈377 \space ohms[/tex]
and
[tex] c= \left( \frac{1}{\mu_o \epsilon_o} \right)^{1/2}≈ 3 x 10^8 \space m/s [/tex]
Two are independent constants (μo and c), and two are dependent.
 

What is the speed of light?

The speed of light is approximately 299,792,458 meters per second in a vacuum. This is considered to be the fastest possible speed in the universe.

What is permeability?

Permeability is a measure of a material's ability to allow magnetic fields to pass through it. In free space, the permeability is constant and has a value of 4π x 10^-7 H/m.

What is permitivity?

Permitivity is a measure of a material's ability to store an electric field. In free space, the permitivity is constant and has a value of 8.854 x 10^-12 F/m.

How are the speed of light, permeability, and permitivity related?

The speed of light, permeability, and permitivity are all fundamental constants of free space. They are related through the equation c = 1/√(μ0ε0), where c is the speed of light, μ0 is the permeability, and ε0 is the permitivity.

Why are the speed of light, permeability, and permitivity important in physics?

The speed of light, permeability, and permitivity play a crucial role in many fundamental laws and equations of physics, such as Maxwell's equations and the theory of relativity. They also help us understand the behavior of electromagnetic waves and their interactions with matter.

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