how did scientists determine the speed of light accurately ?
2006-07-16 22:21:35 · 19 answers · asked by joe 1 in Science & Mathematics ➔ Physics
Do you mean the absolute speed of light in a vacuum?
I read an article a few weeks ago where a group of engineers had slowed light down to almost a complete stop. (a few meters per hour as I recall.)
So iguess your answer would depend on where and in what medium the light is traveling.
From near "0 miles per (you pick the time) " to it's top speed according to Einstein of 299,792,458 metres per second .
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.
or 1,079,252,848.8 kilometres per hour. Converted to imperial units, the speed of light is approximately 186,282.397 miles per second, or 670,616,629.384 miles per hour.
The first quantitative estimate of the speed of light was made in 1676 by Ole Rømer,
Look him up:
Yours : Grumpy
2006-07-16 22:23:40 · answer #1 · answered by Grumpy 6 · 0⤊ 0⤋
The speed of light in a vacuum is an important physical constant denoted by the letter c for constant or the Latin celeritas meaning speed. Light travels slower than c through all other transparent mediums; the ratio of c to this slower speed is called the refractive index of the medium.
In metric units, c is exactly 299,792,458 metres per second or 1,079,252,848.8 kilometres per hour. 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.
2006-07-16 22:45:09 · answer #2 · answered by Whisper4691 3 · 0⤊ 0⤋
(m)
The speed of light in a vacuum is an important physical constant denoted by the letter c for constant or the Latin celeritas meaning speed. Light travels slower than c through all other transparent mediums; the ratio of c to this slower speed is called the refractive index of the medium.
In metric units, c is exactly 299,792,458 metres per second or 1,079,252,848.8 kilometres per hour. 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.
2006-07-16 22:31:21 · answer #3 · answered by mallimalar_2000 7 · 0⤊ 0⤋
there was an experiment in Paris recently which aim was to mesur the speed of light.
They used a laser beam that they send on a mirror at the other end of the city, and they would mesure the time it take for the ray to come back, knowing exatly the distance, they could find the speed of light, wich is 299 792 458 m/s
2006-07-16 22:29:42 · answer #4 · answered by australeolive 3 · 0⤊ 0⤋
186,000 miles per second through air, it goes through solids slower. They used lights on mountaintops and highly sensitive instruments, I forget exactly how they did it. I do happen to think however that just because that's the fastest thing they've found (the speed of light) that that's not necessarily the fastest speed attainable by anything. People can be so closed minded.
2006-07-16 23:21:50 · answer #5 · answered by knowledgeispowerforsure 2 · 0⤊ 0⤋
They study atoms by velocity, force and friction. With this basics they study electronics with a complicated equation of mathematics formulae to count the speed of light. It can be determine by a simple experiment, is to put translucent glasses under the sun and you definitely saw a small fire and smoke emitted. It proves the sunlight has speed to penetrate a small hole.
2006-07-16 22:35:24 · answer #6 · answered by Eve W 3 · 0⤊ 0⤋
If you really want to know how scientists found the speed of light, follow my links. The first one tells the story of improving the method of finding the speed of light, the second one can tell you how to find it yourself (using marshmallows)
2006-07-16 22:32:11 · answer #7 · answered by Anonymous · 0⤊ 0⤋
first of all its reckoned that guy will by no skill benefit the speed of sunshine. the reason for it really is that as an merchandise strikes speedier it begins to achieve mass. the speedier you commute the more suitable your mass will strengthen. travelling on the speed of sunshine or maybe very close to to it may advise your mass may be quite a lot infinite, to that end requiring an quite a lot infinite source of ability to keep you transferring..(Einstein's theory of relativity) As for the time component... the speedier you flow the slower time turns into for you (the traveler) in case you had a twin on earth and also you went for an quite a lot elementary p.c. experience time may commute a lot slower for you. Upon your go back to work out your twin, he/she may have elderly many many years even as you may have infrequently elderly in any respect. Time does decelerate for the traveler, yet does not bypass into opposite.
2016-12-10 10:42:32 · answer #8 · answered by ? 4 · 0⤊ 0⤋
all electromagnetic radiation -- from radio waves to x-rays -- travel at the speed of light. In empty space this speed is approximately 300,000 kilometers per second!
2006-07-16 22:53:29 · answer #9 · answered by Babe 2 · 0⤊ 0⤋
maybe no, but the speed of light is how far light can light up the whole world in 1 second.
maybe thats how they did it.
2006-07-16 22:27:44 · answer #10 · answered by evilstar13 2 · 0⤊ 0⤋