[HN Gopher] Laser pulse travels 300 times faster than light (2002) ___________________________________________________________________ Laser pulse travels 300 times faster than light (2002) Author : nixass Score : 13 points Date : 2021-06-06 22:08 UTC (51 minutes ago) (HTM) web link (optics.org) (TXT) w3m dump (optics.org) | belter wrote: | Paper is 2000 Jul has an Erratum - Published: 21 June 2001 | | Correction: Gain-assisted superluminal light propagation | https://www.nature.com/articles/35082117 | | and a follow up where authors claim a more detailed explanation | of their experiment: | | Published 12 April 2001: | https://journals.aps.org/pra/abstract/10.1103/PhysRevA.63.05... | karmakaze wrote: | > Einstein's Theory of Relativity still stands, however, because | it is still correct to say that information cannot be transmitted | faster than the vacuum speed of light," said Dr. Lijun Wang | ballarak wrote: | I feel as though I'm not understanding something. What would | stop one from transmitting information using the laser pulse? | hatsunearu wrote: | >The 3-microsecond long pulse of light would normally take only | 0.2 nanoseconds to pass through the chamber in a vacuum. But when | passed through the specially prepared chamber, light emerged 62 | nanoseconds earlier than it would have had it passed through the | chamber in a vacuum. | | Am I stupid or does this not make sense to anyone else | layoutIfNeeded wrote: | Something was definitely lost in translation. | ISL wrote: | My guess is that for some definition of "emerged", the three | microsecond-long (3000 ns-long) pulse emerged 62 ns early. | | Most of the results like this involve some sort of anomalous | dispersion and careful definition of the term "emerge". | Relevant keywords you're looking for if you delve into the work | are "group velocity" and "phase velocity". | | TL;DR: Details. They'll matter in this case. | hatsunearu wrote: | Like, is this just pulse compression due to nonlinear wave | effects? If so, it's quite yawn (but it did win a Nobel prize | recently so...) | chovybizzass wrote: | the lazor arrived in da futures | whateveryoua381 wrote: | https://pubmed.ncbi.nlm.nih.gov/10917523/ The nature paper is | probably a better link thank optics.org, this is a few years | before the demonstration, however it has the same claim of 300x | speed of super-luminal (faster than light) group velocity. ___________________________________________________________________ (page generated 2021-06-06 23:00 UTC)