The 38mph result was from 11 years ago, the title of this (2007) article is "Light and matter united" and it's far more startling...<p>> <i>She and her team made a light pulse disappear from one cold cloud then retrieved it from another cloud nearby. In the process, light was converted into matter then back into light.</i>
Maybe I'm dense, but I don't see how this experiment shows that the original light beam was affected in any way. Seems to me that the original light beam etched information onto the "cold atomic cloud", and then later an entirely new beam of light (with identical properties) was emitted (or reflected) from the laser blast's impact on this "etching".<p>How can they reach the conclusion that the original light beam itself was altered from this experiment?
<quote>Einstein and just about every other physicist insisted that light travels 186,000 miles a second in free space, and that it can't be speeded-up or slowed down. But in 1998, Hau, for the first time in history, slowed light to 38 miles an hour, about the speed of rush-hour traffic.
<quote><p>I wouldn't have been surprised if a newspaper journalist used dramatization that indicated as if Einstein is proven wrong. I didn't expect that kind of dramatization when reporting scientific matters on news.harvard.<p>Of course, Einstein is still right. All these experiments slow down the speed of light when it's traveling in special matter at special temperatures. Constant speed of light in free space is a necessary condition for Theory of Relativity be correct. If that condition is found to be incorrect, our current understanding of the universe completely goes for a toss;
This reminds me of something that I think I first read about in Michio Kaku's book Physics of the Impossible where a Bose-Einstein condensate was used as a medium for "teleportation". I believe in his book he referred to the experiment referenced here. <a href="http://www.physorg.com/news102681027.html" rel="nofollow">http://www.physorg.com/news102681027.html</a><p>They are careful to note that it is a transmission of information rather than photons. It sounds like this experiment is similar, but I am certainly not qualified to comment authoritatively on that.
The article seems very loose with its terminology which makes it really confusing. For example:<p>> Albert Einstein and just about every other physicist insisted that light travels 186,000 miles a second in free space, and that it can't be speeded-up or slowed down. But in 1998, Hau, for the first time in history, slowed light to 38 miles an hour, about the speed of rush-hour traffic.<p>Hau did not slow down light in free space so this has nothing to do with Einstein's statement.<p>What I would like to know is, is underlying fundamental mechanism here similar to or the same as what we know as refraction? From all the descriptions it sounds awfully similar, other than the extreme(!) nature of the slowdown.
> For the first time in history, this gives science a way to control light with matter and vice versa.<p>Typical bad science writing.<p>Mirrors have existed before this year...
Check out this great docu <a href="http://www.pbs.org/wgbh/nova/zero/" rel="nofollow">http://www.pbs.org/wgbh/nova/zero/</a> witch shows more of the Bose-Einstein condensate.
the key phrase here is "Despite all the intriguing possibilities, "there are no immediate practical uses," Hau admits."<p>The experiment and its results are intriguing nevertheless.