Mel Beckman <mel@beckman.org> wrote:
An intriguing development in fiber optic media is hollow core optical fiber, which achieves 99.7% of the speed of light in a vacuum.
https://www.extremetech.com/computing/151498-researchers-create-fiber-networ...
Here's an update from 7 years after that article which hints at the downside of hollow core fibre: https://phys.org/news/2020-03-hollow-core-fiber-technology-mainstream-optica... It sounds like attenuation was a big problem: "in the space of 18 months the attenuation in data-transmitting hollow-core fibers has been reduced by over a factor of 10, from 3.5dB/km to only 0.28 dB/km within a factor of two of the attenuation of conventional all-glass fiber technology." Tony. -- f.anthony.n.finch <dot@dotat.at> http://dotat.at/ Shetland Isles: Southeasterly 5 or 6, veering southerly or southwesterly 3 or 4, then backing southeasterly 5 later in southwest. Slight or moderate, occasionally rough later in far west. Occasional rain then mainly fair, but showers far in east. Good, occasionally moderate.