diamonds and the speed of light

[bwanaaa]

It has been published that the speed of light in diamonds is about half the speed in a vacuum. Does anyone know the experiment well?

Why?

 

[Gibsons]

here's a place to start.

http://en.wikipedia.org/wiki/Refractive_index

 

[MetalStorm]

Why is it important?

 

[Gil554]

I will be more interested after the asprin starts to kick in...thanks for the wiki link Gibsons!

G

 

[DrPizza]

actually, it's less than half.
IIRC, index of refraction for diamond is 2.4 (or is it 2.6)? Anyways, it's over 2.. The ratio of the speed in light to that in diamond = 1/2.4

 

[zugzoog]

The speed of light in a medium is 1/Sqrt((electric permittivity)*(magnetic permeability)

 

[MetalStorm]

Originally posted by: zugzoog
The speed of light in a medium is 1/Sqrt((electric permittivity)*(magnetic permeability)

Hmm, quite intriguing.

I still wonder why bwanaaa needs to know the speed of light in dimonds though?

 

[CycloWizard]

Originally posted by: MetalStorm

Originally posted by: zugzoog
The speed of light in a medium is 1/Sqrt((electric permittivity)*(magnetic permeability)

Hmm, quite intriguing.

I still wonder why bwanaaa needs to know the speed of light in dimonds though?

He's trying to build a diamond-based laser to make it snow at the beach!

 

[Gibsons]

probably a repost, but interesting ---

article about synthetic diamonds
http://www.wired.com/wired/archive/11.09/diamond.html

Company mentioned in article that makes near-perfect diamonds by chemical vapor deposition
http://www.apollodiamond.com/

fun to speculate what all could be done with them if they can make them big/cheap/fast enough.

 

[Pohemi]

Don't know if this is off topic, but...

I think it was about 2 yrs ago now, a couple of European scientists actually accelerated a beam of light carrying data past the known and accepted speed of light. The way I understood the explanation, the beam actually finished being received at point B before it had completely left the point of origin, or point A.

They achieved this by projecting the beam through a special high density sodium gas of some type. They stated that while they don't forsee ever being able to do this with solid matter, it could revolutionize communications and even computer hardware. Interesting thoughts...

 

[mwmorph]

yes but that would viaolate cause&effect. it wouldnt be possible physically would it?

 

[JediJeb]

I read about the speeding up of light also, it was where someone found a substance with a negative index of refraction, which only means that light travels faster through that substance than it does in a vacuum. Now if they could make fiber optic from it then they could speed up communications, but when it only takes a fraction of a second to transmit light around the world how much benefit would it really have.

 

[DrPizza]

Originally posted by: JediJeb
I read about the speeding up of light also, it was where someone found a substance with a negative index of refraction, which only means that light travels faster through that substance than it does in a vacuum. Now if they could make fiber optic from it then they could speed up communications, but when it only takes a fraction of a second to transmit light around the world how much benefit would it really have.

I thought the negative index of refraction crystals referred to crystals where light bent backwards (it's easy to draw the picture, but hard to put into words)

------
/

(except the bottom one should be closer to the normal)

 

[Anubis08]

It is also why diamonds sparkle (and even the back of cds). Light goes in and is bounced around inside until it can hit at a high enough angle (closer to 90 degrees the better) on a surface and come out. By this time it could be cancelled or part of the spectrum cancelled by another incident light ray. For a cd, imagine two layers. The top is a little reflective and the bottom is totally reflective (I know it is ideal). When light strikes the top surface, some is reflected and the rest goes through, so, if the distance to the next surface is 1/4 the wavelentgh of a certain light color, it will be opposit when it strikes the surface again and will cancel the incident light of that spectrum that is incoming and bounces off the top surface. However, some will bounce back again and when it comes up again it will amplify that spectrum. That is why you see a "rainbow" in a cd. Kind of how rainbows work to now that I think of it. Trivia: The sun has to be at 45 degrees or less to the horizon to see a rainbow.

 

[Anubis08]

Sorry, forgot one other thing. I read about an experiment where they created a solid by supercooling it with a laser that actually slowed light down to 34 mph. They hoped by now to have slowed it down to 1 inch per second, but I have heard nothing more of them.