2007-10-29 06:03:42 · 8 answers · asked by mad_xpert 2 in Science & Mathematics ➔ Physics
Light does in fact travel slower in earth's atmosphere than in outer space. Light and all EM waves travel at different speeds in different mediums. The ratio of the speed in a medium to the speed in free space is called the relative permitivity (or dielectric constant) and can be found in reference books or online for most materials. The value for air is 1.00054, meaning EM waves travel almost the same speed in a vacuum or in air. In contrast the permitivity of glass is abour 4.7, meaning light travels 4.7 times slower in glass than in free space.
2007-10-29 06:18:08 · answer #1 · answered by Andrew K 6 · 0⤊ 0⤋
Light travels marginally slower through Earth's atmosphere than it does through a vacuum, but the difference is tiny. In fact, the two values are so close that you can use 300,000 km/s for either and not be too far off. In denser transparent materials, like glass or water, the speed of light is significantly slower.
2007-10-29 06:09:14 · answer #2 · answered by Lucas C 7 · 0⤊ 0⤋
Unlike sound, light travels faster through a vacuum than through a medium. So yes, light travels slower in the Earth's atmosphere, compared to space.
2007-10-29 06:09:09 · answer #3 · answered by Anonymous · 0⤊ 0⤋
The Speed of light depends on the Density of the medium in which its traveling. In air the speed of light is different than the speed of light in water.
The Speed of a light ray at the surface of the Earth is faster due its gravity field than where the gravity field is weak..
Hence time as well as velocity of light Changes at the different Gravity pressure levels in the Universe. If light is a micromass structure of a set constant dimension(not
changing) and if Time is diferrent in space at various levels, then Velocity being the ration of space distance and time would therefore change accordingly.
Note the Speed of light has only been measured relative to the Earth, but never relative from the Center of the Universe. The Reason is that no one really knows exactly where is the center of mass of the Universe .
Very vely simple.
2007-10-29 06:19:25 · answer #4 · answered by goring 6 · 0⤊ 2⤋
Yes, it does. As it also travels slower in -any- medium that isn't a vacuum. And the difference in its velocity is a physical characteristic of the medium called its 'refractive index' (-not- its permeability or permittivity, although they do contribute to its refractive index). And it has absolutely nothing to do with gravity. Light in a vacuum travels at almost 3X10^8 m/s in -any- inertial reference frame as measured by an observer -in- that reference frame.
Doug
2007-10-29 06:27:07 · answer #5 · answered by doug_donaghue 7 · 1⤊ 1⤋
there is a speed differnce but it is very slight. 300,000km/h is a good number to use for light speed on earth as in space.
2007-10-29 06:11:08 · answer #6 · answered by Anonymous · 0⤊ 0⤋
yes, but not much slower.
2007-10-29 06:21:35 · answer #7 · answered by SDS 2 · 0⤊ 0⤋
yes, but not much slower.
2007-10-29 06:11:35 · answer #8 · answered by sweety_atspacecase0 4 · 0⤊ 0⤋