Speed of Light

Yes. Other units such as miles, kilometers or astronomical units are too tiny to be practical in discussing the distances between the stars, or between the galaxies.

One even larger unit is often used in astronomical measurements, the "parsec". This is the distance of one "parallax second of arc", and is approximately equal to 3.26 light years. For long distances across the galaxy, some astronomers use "kiloparsecs" as a unit of measure, and for intergalactic distances some astronomers use "megaparsecs" or "Mpc".

Remains unaltered

The speed of light is constant and does not change based on the material it passes through. However, when light enters a medium such as glass or water, its speed decreases due to interactions with the atoms in the material.

-- Its speed increases.

-- Its wavelength increases.

-- It refracts away from the normal to the interface at the point of incidence.

The refractive index is the ratio of the speed of light in a vacuum to the speed of light in a medium.

If one thinks about the possible states of the Universe, there are three possible situations - it's expanding, it's standing still or it's contracting. Einstein made, what he described, as his biggest blunder by assuming it stood still - as he said, a few seconds thought should have shown that a stationary Universe will immediately start to collapse under gravity. Hubble observed that objects in the Universe are moving away from Earth and that more distant objects are moving faster. The explanation of this comes from General Relativity and is interpreted as an expanding Universe, however it takes a few minutes calculation to realise that as we think about the further reaches of space, it is expanding at rates far greater than the speed of light (c). This seems to contradict Special Relativity and is getting a bit beyond my knowledge(!), but its solved by not thinking of the edge of the Universe zooming along well beyond c, it's not zooming into anything, it's simply getting bigger. So, yes it is expanding, and at enourmous (by our standards) rates.

A "fact" is basically anything you can state, especially if such a statement is true. Since you can say "light has a speed", and since that is true, it follows that it's a fact.

Light through a "vacuum" is the meaning of "the speed of light." Light through glass is slower.

Between 100,000 and 180000 years.

i got pulled over going 40 mph on my crf 50

The speed of light is a constant, so the acceleration is zero.

However, light IS affected by gravity, and gravity causes an acceleration. How does this balance? The light moves at the same speed - the speed of light, abbreviated "c" - but loses or gains energy as the light moves toward or away from the gravity source.

In gaining energy (without speeding up!) the frequency of the light is increased and the wavelength of the light (or any electromagnetic energy) is decreased, In losing energy, the wavelength is increased and the wavelength decreased.

This could be a trick question, of course. Light from a star wouldn't be travelling from earth, unless we are talking about reflected light, which would not be particularly intense, but it is not out of the question.

Yes, all light travels at the same speed in a vacuum. The speed of light in other media, such as water or glass, is slower than it is in a vacuum. That is the basic principle that makes lenses and prisms work the way they do. In a given medium, however, all electromagnetic waves travel at the same speed.

Because of how our eyes respond to light, it's not as straightforward as it could be, but basically the higher (in frequency) the location of the peak, the more "blue-shifted" the color will appear.

Because there's considerable intensity on either side of the peak, the object appears red while the peak is still down in the infrared region, and when the peak is in the green region the source will appear white.

The speed varies according to the refractive index of the objects.

You divide the speed of light in a vacuum (about 300,000,000 meters/second) by the index of refraction, "n".

Located on the rear axle housing and held by a mounting bolt.

This is called the index of refraction. When light crosses the boundary between mediums (media) with different indices, it is bent (refracted).
It's usually defined the other way around ... the ratio of the speed of light in vacuum to its speed in the medium. Since the speed of light is greater in vacuum than in any medium, the number is always greater than 1. It's referred to as the "refractive index" of the medium.

The distance from the Sun to the Earth varies about 3% over the course of a year, from a minimum or "perihelion" distance of about 91,500,000 miles to a maximum or "aphelion" distance of about 94,500,000 miles. 93 million miles is a good average figure. Details of how to measure this distance are given later.

The speed of light is approximately 186,000 miles per second, or 300,000 kilometers per second. With an average distance of 93 million miles and an approximate speed of light of 186,000 miles per second, the math becomes really easy; it takes light 500 seconds to reach the Earth.

Here's one method of how to measure the distance to the Sun, using radar technology:

(You can't use radar to measure the distance to the Sun directly

because of the nature of the Sun's surface.)

1) Wait for Earth, Venus and the Sun to line up with Venus (more or less) directly between us and the Sun.

2) Measure the distance to Venus using radar.

3) Knowing the Earth to Venus distance, use Kepler's Third Law to find the Earth to Sun distance.

(Kepler's Third Law will give the ratio of the distances of Earth and Venus from the Sun. Thus, knowing the Earth to Venus distance, you can find the Earth to Sun distance.)

See the "Related Link" below for more about measuring the distance to the Sun.

Rays at normal incidence ... perpendicular to the interface ... obey the same law of

refraction that rays at any other angle do.

I won't write the equation of refraction here, because you probably already know

what it looks like, and if you're a little rusty, you can easily find it on line or in your

Physics text as "Snell's Law". The law of refraction relates the angles with respect

to the normal in each medium to the index of refraction in each medium.

In the formula, the angles are referenced in terms of their sines. If the incident ray

is perpendicular to the interface, then the sine of the angle of incidence is zero. Then,

regardless of the relative optical densities of the two media, the sine of the angle of

refraction is also zero. The ray that arrives along the normal is refracted after all,

through an angle of zero.

To rotate a mirror so that a reflected ray rotates through 25 degrees, the mirror should be rotated half that angle, which is 12.5 degrees.

Recent experiments at CERN suggest that neutrinos travel faster than light, but this experiment has not been replicated anywhere else and needs significant backing before it is to be accepted as a phenomenon.

It will depend on the type of glass, and something called its refractive index. All materials have a refractive index which will effect the speed of the light through it. The speed of light through a vacuum is 3.0x10^8 m/s, and a material such as glass will be lower than this.

No, light in a medium will travel at a slower speed.

The question gives no information concerning the distance the person covered,

so his speed can't be calculated.

The ability to travel 530 minutes in 10 hours requires moderate sedation.