What is the speed of Light ????

Answer 1

299,792,458 metres per second (1,079,252,848.8 km/h)

Answer 2

The speed of light is different depending on the medium through which it is travelling. In other words, it moves faster through air than glass or plastic. The fastest speed at which light can travel is in a vacuum, where there are no atoms to get in the way. It is about 671 billion miles per hour, or 182 thousand miles per second (see this link for other units: http://en.wikipedia.org/wiki/Speed_of_light ). At that speed, a ray of light would take almost 2 seconds to get to the moon from earth, and about 8 minutes to reach you from the sun. The light coming from the stars can take hundreds, thousands, or even millions of years to reach us. In some cases, the stars may have burned out long ago, but still are shining in our sky.

Answer 3

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. 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.

Answer 4

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Quantum of light is a privileged particle.
Only the speed of a light quantum has
a maximal, constant, absolute quantity of c=1.
No other particle can travel with the speed c = 1.
If quantum of light flies always rectilinearly c=1, it is a mad one.
Is he really mad?
* * *
Only a light quantum has the absolute speed c=1.
No other particle can travel with the speed c = 1.
Other particle can travel only with the speed v=s/t.
And I was taught at school from the first class:
that the incommensurable quantities cannot be compared.
To connect incommensurable quantities it
is similar to the decision of a problem:
“What will be if the whale will attacks the elephant?”
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Quantum of light have two kinds of spins,
as a result of which the particle attains motion.
1)
Under the action of Planck,s spin,
which is equal to the unit ( h =1)
aquantum of light flies rectilinearly with speed (c = 1).
The geometrical form of a circle: (C/D = 3,14).
A quantum of light behaves as a particle.
2)
Under the action of Goudsmit-Uhlenbeck's spin, ( ħ = h / 2pi)
a quantum of light rotates around of its diameter
with the speed more of light quanta : c>1
and is known as electron.
The geometrical form of a circle is transformed into a sphere.
This kind of movement is described by Lorentz's transformations .
The wave properties of light quantum are shown.
The dualism of a particle becomes clear.
The paradox of dualism disappears completely.
When the form of a circle is change into the form of a sphere,
the transcendental magnitude (pi = 3,14) is change
on another transcendental magnitude (е = 2,71).
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http://www.socratus.com
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Answer 5

The speed of light is the speed at which electromagnetic waves can move in a vacuum: 299,792,458 meters/sec (186,000 miles/second). According to Einstein's Theory of Relativity, nothing can go faster than the speed of light. SPEED OF SOUND The speed of sound is the speed at which sound moves through air. At sea level and standard atmospheric pressure, the speed of sound is 1116.45 feet per second (340.294 meters per second).

Answer 6

In metric units, c is exactly 299,792,458 metres per second, c being the speed of Light.



Here's a link to the wikipedia article on it for more in depth knowledge.

Answer 7

It is the speed at which electromagnetic waves can move in a vacuum...
About 186,000 miles/second.

Answer 8

Roughly 186,000 miles per second. Whoa!

Answer 9

3x10^8 m/s (more exact: 299,792,458 m/s).

Not to be rude, but isn't a web search a LOT faster than waiting for Yahoo Answers on something like this?

Answer 10

300 000 km per second,but I do not no exactly ,its between 299 000 until 300000

Answer 11

299,792,458 metres per second
1,079,252,848.8 km/h
186,282.397 miles per second
670,616,629.384 miles per hour