0
The speed of light (and all other forms of electromagnetic radiation) in vacuum is determined by
the electrostatic permittivity (ε0) and magnetic permeability (μ0) of free space.
An interesting thought ... we have no way of knowing whether these physical constants are the same
numbers today that they have always been. If either of them has changed since the birth of the universe,
then the speed of light changed, and our observations of the earliest cosmos give an erroneous number
for the age of the universe.
But anyway, that's what these quantities are today, and they're what determines the speed of light,
as is so neatly predicted by Maxwell's equations and verified spot-on by the best measurements.
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∙ 14y ago
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How can the index of refraction for different substances be determined mathematically?
n(index of refraction) = c(speed of light in a vacuum)/v(speed of material in the sebstance)
What happens to frequency does the speed of light ever change?
The speed of light IN A VACUUM is always the same. In substances other than the vacuum, the speed of light is usually slower than in a vacuum.
Can the speed of light be calculated?
Answer: The speed of light was determined through experimentation, such as the timing of moons passing behind Jupiter. Many formulas are based upon the speed of light, but that number had to be determined beforehand. Light travels 299,792,458 meters per second (or 186,282.397 miles per second in a vacuum. Answer: Yes, the speed of light can be deduced from the electrical properties of empty space. However, in practice it is more accurate to measure the speed of light.
What percentage of the speed of light in vacuum is the speed of light in water?
When light with wavelength of 589 nanometers moves through water at the temperature of 20° C, its speed is 75% of the speed of light in vacuum.
Is speed of light uniform or not?
The speed of light in a vacuum is constant everywhere. The speed of light in a particular medium depends on what the medium is. It moves slower in air than in a vacuum, and slower in water than in air.
Why speed of light is constant in vaccum?
Because the speed of light is determined by the electrical characteristics of the medium, and the electrical characteristics of vacuum don't change.
Why is the speed of light limited in a vacuum?
The speed of light is not limited in a vacuum - the speed of light is fastest in a vacuum. But that is what Einstein called the "Cosmic Speed Limit" - nothing can move faster than the speed of light in a vacuum, or even quite asfast.
How can the index of refraction for different substances be determined mathematically?
n(index of refraction) = c(speed of light in a vacuum)/v(speed of material in the sebstance)
What is the speed of light through the liquid whose refractive index you have determined?
If the refractive index is k then the speed of light is c/k metres per second where c is the speed of light in vacuum (approx 299,792,458 m/s).
Does the speed of light change in a vacuum?
No, not as long as the light stays in vacuum.No, it does not. That is where it has its maximum speed.
What happens to frequency does the speed of light ever change?
The speed of light IN A VACUUM is always the same. In substances other than the vacuum, the speed of light is usually slower than in a vacuum.
Which of these is constant for ALL types of electromagnetic radiation in a vacuum?
Answer = Velocity Velocity is the speed of light and, the speed of light, is a constant among Electromagnetic Radiation in the vacuum of space.
Can the speed of light be calculated?
Answer: The speed of light was determined through experimentation, such as the timing of moons passing behind Jupiter. Many formulas are based upon the speed of light, but that number had to be determined beforehand. Light travels 299,792,458 meters per second (or 186,282.397 miles per second in a vacuum. Answer: Yes, the speed of light can be deduced from the electrical properties of empty space. However, in practice it is more accurate to measure the speed of light.
What is the speed of light of a vacuum?
In vacuum, the speed is 299,792,458 meters per second.
How does the average speed of light glass compare with its speed in a vacuum?
About 2/3 its speed in a vacuum.
What percentage of the speed of light in vacuum is the speed of light in water?
When light with wavelength of 589 nanometers moves through water at the temperature of 20° C, its speed is 75% of the speed of light in vacuum.
Is speed of light uniform or not?
The speed of light in a vacuum is constant everywhere. The speed of light in a particular medium depends on what the medium is. It moves slower in air than in a vacuum, and slower in water than in air.
