This particular perspective is technical and if I understand correctly only suggests a few specialised situations where light might be speeded up. I have not grasped by how many orders of magnitude, but the headlines do not for example, even claim a doubling.
The abstract starts by noting the relevance to Einstein's theory of relativity.
Despite being an amiable, and progressive anarchistic son of a bourgeois, Einstein is known for his idealist tendencies ("God does not play dice", his search for the single unified field theory, his assumption that time can run backwards).
It would fit if he were revealed also as having mechanical tendencies.
The assumption that half a dozen "constants" of fundamental physics really are constants is coming under increasing question.
There are so odd that the question is increasingly asked whether they are not to be explained statistically, that out of all the various possibilities, only a narrow range of constants are the set that could permit life, and our own intelligence to evolve - the anthropic perspective.
Did not Marx or Engels say something about having no fixed point from which to observe the universe? I cannot place the quote.
Chris Burford
London
At 22:51 20/07/00 -0700, you wrote:
>Gain-assisted superluminal light propagation
>
>L. J. WANG, A. KUZMICH & A. DOGARIU
>
>NEC Research Institute, 4 Independence Way, Princeton, New Jersey
>08540, USA
>
>Correspondence and requests for materials should be addressed to
>L.J.W. (e-mail: Lwan at research.nj.nec.com).
>
>
>Einstein's theory of special relativity and the principle of
>causality(1-4) imply that the speed of any moving object cannot exceed
>that of light in a vacuum (c). Nevertheless, there exist various
>proposals(5-18) for observing faster-than- c propagation of light
>pulses, using anomalous dispersion near an absorption line(4),(6-8),
>nonlinear(9) and linear gain lines(10-18), or tunnelling
>barriers(19). However, in all previous experimental demonstrations,
>the light pulses experienced either very large absorption(7) or severe
>reshaping(9, 19), resulting in controversies over the
>interpretation. Here we use gain-assisted linear anomalous dispersion
>to demonstrate superluminal light propagation in atomic caesium
>gas. The group velocity of a laser pulse in this region exceeds c and
>can even become negative(16, 17), while the shape of the pulse is
>preserved. We measure a group-velocity index of ng = -310(+-5); in
>practice, this means that a light pulse propagating through the atomic
>vapour cell appears at the exit side so much earlier than if it had
>propagated the same distance in a vacuum that the peak of the pulse
>appears to leave the cell before entering it. The observed
>superluminal light pulse propagation is not at odds with causality,
>being a direct consequence of classical interference between its
>different frequency components in an anomalous dispersion region.
>
>see:
>
>http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/
>v406/n6793/full/406277a0_fs.html