71–80 of 268 posts
Eliminate deep sea cables? How are they going to send the lasers in a curve from one base station to the next? Starlink is already working on a backhaul from satellite to satellite. Interestingly, they claim that they can speed up data transfers by 50% over long distances. Musk said that in a Tweet which I cannot find now. I looked a bit into it and the reason seems to be that light trough a cable can only reach 70%…
Aren’t lasers extremely susceptible to weather conditions? E.g. when it’s raining/snowing/cloudy, can the base station communicate with a satellite via laser?
While this experiment has demonstrated that it is possible to compensate for the turbulence of the air, there is no solution for the attenuation caused by bad weather.
It might be possible to use lasers between a base station and satellites only if the base station is located at high altitude in a dry place, like those typically chosen for astronomical observatories, so that the links will be blocked by bad weather only infrequently.
So I do not believe that there is even a remote chance of replacing most undersea cables.
This sure sounds useful, but "might remove need for deep-sea cables" is quite silly. Anything they do to cram bandwidth into their laser link can reasonably also be applied to fiber optical cables. Except the fiber optical cables come in bundles of 12 to 144 with absolutely no separation issues. Replicating that over open space (air or vacuum), if reasonably possible at all, will chug significant amounts of power in…
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Fair! And the existing MW re-translator towers can be upgraded / reused this way. Lasers have a downside though: optical and near IR light is much more readily absorbed by water vapor than microwaves. I wonder if a maser would be an acceptable solution, if cheaper versions of it existed.
1550nm water is super transparent.
While 1550 nm falls between two absorption maxima of water, so it is not the worst choice, the absorption in water is still more than one hundred times higher than at e.g. 905 nm.
Because of this, 1550 nm is absorbed through fog or clouds at least 3 to 5 times more than shorter wavelengths like 905 nm. Even the latter is absorbed a lot by water, while being much more dangerous for eyes than 1550 nm.
There is no near infrared wavelength where the water absorption is negligible.
See the graphs at:
https://en.wikipedia.org/wiki/Electromagnetic_absorption_by_...
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> require a generational shift to deploy. Photonic bandgap / Bragg fiber is being produced in quantity, and some subsea cables are using it. I'm pretty sure it's the satellite lasers that require the generational shift. One subsea cable has no bearing on any other; once the first is installed, you're up and running. not so with laser-connected swarms.
Starlink's laser connections have been active for a year now.
Current fiber optic cables transmit signals at 2/3rds the speed of light. Modeling has shown that starlink's laser backbone would allow it to beat deep-sea cables in some situations. This article estimates a NYSE -> FTSE reduction from 76ms to 43ms. I wouldn't be surprised to learn that there is a HFT bidding war going on. https://archmeregreenarch.org/1456/news/starlink-and-the-ris... There is a newer version of fib…
HFT changes these "beliefs in company" to "beliefs that the stock will go up", and the timeframe of those "beliefs" is sometimes in milliseconds. This turns classic "investment" into a computer game with a lot of real money.
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Currently, you can cut internet connections to most countries with a small deep water sub. China, for example, was busy building one that can be used at 10k+ depth and has arms.
Its widely assumed China, Russia and the US have "kinetic kill" abilities on satellites in space too, its just capabilities are not as widely known. Projects Like the US/Boeing X-37 space drone etc, whose purposes still haven't really been revealed: > https://en.wikipedia.org/wiki/Boeing_X-37 Russia has already demonstrated its satellite destroying tech: > https://www.cnbc.com/video/2021/11/16/russia-blows-up-satell.…
It is basically automatic MAD (Mutually Assured Destruction) out there in space.
The key thing here is it allows for very high bandwidth to go almost anywhere on earth, not just spots where it's easy to land a cable. Starlink's already demonstrated how great that is for consumer bandwidth (50Mbps); a multi-gigabit link terminated at a satellite is fantastic. The part that impresses me most is they're talking about LEO satellites. Those move fast! Starlink does this with a very impressive phased a…
> how great that is for consumer bandwidth (50Mbps) 50 Mbps is great consumer bandwidth where?
An advertised "50 Mbps" mobile connection is dog food if you are used to 50 Mbps fiber. You are lucky if you get 20 Mbps through, though it can be much less. Worst part is all the packet loss that cause inconsistent latency and speed.
If nothing else I could see governments insisting on both just for strategic reasons. Both techs are vulnerable to being fk'd with so doubling up makes sense
Current fiber optic cables transmit signals at 2/3rds the speed of light. Modeling has shown that starlink's laser backbone would allow it to beat deep-sea cables in some situations. This article estimates a NYSE -> FTSE reduction from 76ms to 43ms. I wouldn't be surprised to learn that there is a HFT bidding war going on. https://archmeregreenarch.org/1456/news/starlink-and-the-ris... There is a newer version of fib…
Am I the only one who thinks HFT should be forbidden? Stocks and investments are a nice thing to have, since you can buy a share of a company you believe in, they get the money, do stuff, you get dividends and in the end can sell the stock after some time too. HFT changes these "beliefs in company" to "beliefs that the stock will go up", and the timeframe of those "beliefs" is sometimes in milliseconds. This turns cl…
It would take a heavier hand to push against this problem. I'm all for it, I'm just not clever enough or knowledgeable enough to know what would be a good regulation that would fly in congress.