Slow light

[ZygoUgo]

I remember reading a short story about windows that slowed down light so you could see what was happening outside in the past, quite a cool little tale, and all the more likely now
http://www.news.harvard.edu/gazette/200 ... light.html

[Smivs]

...and no jokes about "I remember reading a short story about windows that slowed down light so much the screen blue shifted..."

[Killer Wolf]

"temperatures a billion times colder than those in the spaces between stars. The atom cloud was suspended magnetically in a chamber pumped down to a vacuum 100 trillion times lower than the pressure of air in the room where you are reading this. "

yeah whatever, i think they're just making that sht up, hoying numbers like that around. a BILLION times colder? really?

[ZygoUgo]

There's always seems to be some desperation to get people interested in these sorts of projects, so maybes, probably to do with funding.
I saw some vid of an undersea (sunken) city the other day, and there was some terrible shoehorning of Atlantis in there They even compared what was supposedly a pyramid with a naff painting of a pyramid with a giant crystal on its top, like it was nabbed from some dodgey 60's sci-fi poster

[Micha]

I remember reading a short story about windows that slowed down light so you could see what was happening outside in the past

Isn't that what we call 'TV' these days?

[ZygoUgo]

That's a very good point, I especially like past representations of the future

[Ganelon]

Ladies, gentlemen and err.. gentlebeings (or whatever you are with the tentacles over there in the corner)..

Slow light is nifty and all that, but don't forget the other extreme. There is also superluminosity, or light which propagates faster than the speed of light.

http://physicsworld.com/cws/article/news/17870

For those who might want a bit more of the technical explanation of those experiments, you can find a pdf by one of the researchers (Boyd) here:

http://www.optics.rochester.edu/workgro ... OLS_04.pdf

It's only 3 pages long with a couple charts and a diagram showing the basic setup for the experiments. Nothing too scary. And it doesn't use hard to grasp ideas like "a billion times colder" or "a vacuum 100 trillion times lower than the pressure of air in the room where you are reading this" because they did it at room temperatures.

[JensAyton]

yeah whatever, i think they're just making that sht up, hoying numbers like that around. a BILLION times colder? really?

The temperatures used in this sort of experiment are on the order of 5E-10 kelvins. The interstellar medium varies between about 10 and 1E7 kelvins. So actually, that would be 20 billion to 20 quadrillion times colder than the spaces between the stars… except that temperature isn’t the same thing as heat, so “colder” is at best ambiguous.

On the other hand, the implication that we just found out that you can slow light down is unmitigated bullshit. Shining it through water slows it down by about a third – which, admittedly, is still a lot faster than in the experiments. The varying speed of light is responsible for well-known effects like  the blue glow from nuclear reactors and, more prosaically, [wp]refraction[/wp].