what is the speed of light in?

Question

what is the speed of light in
1-inner space
2-dence atmosphere
3-salty water
4-minaral water
and 5-tape water

Answer 1

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!

Answer 2

You ask a seemingly simple question but one that is not so easy to answer. We have a "proper" definition for the speed of light in a vacuum but I think what is more useful is the question "How far does light (or a specific frequency of light) travel in the media that you have specified.

You are missing some additional information in your question which are as follows:
(1) inner space <= vacuum - not problem here
(2) dense atmosphere <= Unknown atmospheric contents i.e. gas composition and temperature
(3) salty water <= salt content
(4) mineral water <= mineral content
(5) tap water <= chlorine content, temperature.

M.C.

Answer 3

It does vary slightly with regard to your list.
However, and I do not have details, an experiment was carried out in lab that shone light through a crystal that had been reduced in temperature to just 0.4 Kelvin, and the resulting recorded speed of the light was 31 miles per hour.

This is only what I have been told, but I'm sure somebody may have a record of the experiment. It was featured once on the UK panel game QI, hosted by Stephen Fry.

Answer 4

According to Science and Physics Concept the speed of light is 3 x 10^8 m/s

But to the quantum Mechanic Postulate no. 4 the speed of light would differ and this is well in advance argued in Tao of Physics

Nowadays we only follow the science

Answer 5

In a vacuum, it's 299,792,458 metres per second. At a wavelength of 589.3nm, this value is divided by the following refractive indices to get the speed of light in this medium:

1. By inner space, I assume you mean a vacuum, in which case it is 1 (i.e. the speed above)
2. Air: 1.0002926
3. Not sure. Salt (NaCl) is 1.544, though. Shouldn't be much different from pure water
4. Depends on the minerals. Pure water is 1.333
5. I assume you mean tap water. Again, depends on what's in it, but shouldn't be massively different from pure water

Answer 6

in air, the speed of light is approx 186000 miles per second, and depending on how much water for example it passes through, it will eventually slow down untill you can not see it any more. The further you dive into the ocean for example the less light that reaches the bottom, this is why in shallow places, you can see a lot of it, but as you go deeper it will eventually get dimmer

and what the last person who answered said is not true, sound and light are equal they both slow down depending on what medium they pass through

Answer 7

The speed of light is given by v=c / n where c is the speed of light in a vacuum and n is the refractive index of the material it is passing through.

So you just need to lookup the refractive index for each material and find the speed of light in a vacuum (approx 3*10^8 m/s)

Answer 8

Start here: http://en.wikipedia.org/wiki/List_of_indices_of_refraction

Once you are out of a vacuum, you can no longer talk about the "speed of light." You have to start talking about the speed of particular frequencies of light, because each medium (what the light is passing through) has a different "index of refraction" for each frequency. It's why we see rainbows and why prisms work the way they do.

Answer 9

The speed of light is the speed of light no matter, what/were its travelling, the same as, the speed of sound, when measured by th

e mach remains the same, no matter what,its travelling thru!

Answer 10

Lightspeed.