2006-11-15 04:06:36 · 21 answers · asked by mead2k74eva 1 in Science & Mathematics ➔ Physics
The speed of light in a vacuum is an important physical constant denoted by the letter c for constant or the Latin word celeritas meaning "swiftness". It is the speed of all electromagnetic radiation in a vacuum, not just visible light.
In metric units, c is exactly 299,792,458 metres per second (1,079,252,848.8 km/h). Note that this speed is a definition, not a measurement, since the fundamental SI unit of length, the metre, has been defined since October 21, 1983 in terms of the speed of light: one metre is the distance light travels in a vacuum in 1/299,792,458 of a second. Converted to imperial units, the speed of light is approximately 186,282.397 miles per second, or 670,616,629.384 miles per hour, or almost one foot per nanosecond.
Through any transparent or translucent material medium, like glass or air, it has a lower speed than in a vacuum; the ratio of c to this slower speed is called the refractive index of the medium (the actual speed is not affected, the speed of light is constant, the fact that the light is reflected around inside the glass will make a greater amount of time necessary for it to reach the next point). Changes of gravity, however, warp the space the light has to travel through, making it appear to curve around massive objects. This gives rise to the phenomenon of gravitational lensing, in which large assemblies of matter can refract light from far away sources, so as to produce multiple images and similar optical distortions.
click here:http://en.wikipedia.org/wiki/Speed_of_light#Overview
2006-11-15 04:08:17 · answer #1 · answered by Anonymous · 6⤊ 1⤋
solid sufficient. Time does not flow slower for speedy products. apparently to you, assuming you're table certain, that aspect is passing slower for speedy products. If there are not any accelerations advantages - each and every thing is continually transferring on the equivalent speeds relative to at least one yet another - then there's no thanks to inform who's moving and who's at relax. Now the dual paradox, that you variety of paraphrased the following, has 3 accelerations in it. you commence from leisure and income an rather severe velocity. After a time, you turn round which means you slow down, you momentarily give up, and also you % as a lot as a severe % again. for this reason you attain earth and sluggish to a stop. At each and each and every acceleration, you adventure a force which the earthbound human being does not so that is sparkling who's in circulation and who's at relax. hence, you're going to go back after 10 years a even as maximum helpful to seek out that a a lot longer time has handed on the earth. Now celeb trek assumes there's a thanks to adventure exterior of the 4 dimensional area that defines the universe - the so-common as subspace. in this subspace, relativity does not keep on with - that is exterior the universe quite somewhat - so that you may want to flow from aspect to ingredient in a finite era of time and, the time it takes to traverse the hollow as measured by the starship's clock may be the time that elapses contained in the universe - kind of not likely besides the undeniable fact that imperative if you're writting one hour lengthy television episodes. there is not any information for this style of shuttle use in in call for human being trek.
2016-11-29 04:06:56 · answer #2 · answered by santella 4 · 0⤊ 0⤋
In proper scientific notation and SI units and to 2 sig figs
the speed of light is:
3.0*10^8 m s-1 (metres per second)
2006-11-15 04:42:54 · answer #3 · answered by town_cl0wn 4 · 0⤊ 0⤋
it would appear it depends on your religion.....
299,792.458 km/s is the speed of light in vacuum. However, according to Einstein's theory of General Relativity, the speed of light appears to vary with the intensity of the gravitational field.
But 1400 years ago it was stated in the Quran (Koran, the book of Islam) that angels travel in one day the same distance that the moon travels in 1000 lunar years, that is, 12000 Lunar Orbits / Earth Day. Outside gravitational fields 12000 Lunar Orbits / Earth Day turned out to be the known speed of light!
Or. The speed of light, sometimes known as "C" (as in E=MC2), is a constant of the Universe
2006-11-15 04:10:50 · answer #4 · answered by dsclimb1 5 · 1⤊ 0⤋
speed of light
: a fundamental physical constant that is the speed at which electromagnetic radiation propagates in a vacuum and that has a value fixed by international convention of 299,792,458 meters per second -- symbol c
2006-11-15 04:12:57 · answer #5 · answered by kosmoistheman 4 · 1⤊ 0⤋
speed of light varies from medium to medium. in optically rarer medium like air and vacuum, light travels with a speed of about 300000 km/s when viewed from a frame of reference at rest w.r.t. the medium. strong magnetic fields can affect the velocity of light.
2006-11-15 05:18:57 · answer #6 · answered by Anonymous · 0⤊ 0⤋
in vaccum speed of light- 38X10000000m/sec or 3.8X 10to the power 8 m/sec (fastest)
speed of light decreases with increase in refractive index( i.e. denser mediums like water, glass slabs, diamond etc.)
2006-11-15 04:15:04 · answer #7 · answered by coolzabhishek_007 2 · 0⤊ 0⤋
3*100000000 m/s.
or three into 10 to the power 8 metre per second.
2006-11-15 04:11:41 · answer #8 · answered by Anonymous · 1⤊ 0⤋
3 lakh km/ second = speed of light
2006-11-15 04:08:06 · answer #9 · answered by Dhirs 2 · 0⤊ 1⤋
299 792 458 m / s = light
speed of sound at sea level = 340.29 m / s
2006-11-15 04:15:10 · answer #10 · answered by Anonymous · 1⤊ 0⤋