4 ms·

150ms round trip California to the Netherlands. Oof. That's like 9 frames of a 60fps video. The speed of light sucks! Someone should do something about that!

PeterCorless 7y ago
You can if you make the Planck constant a variable. People are postulating it just might be under the right conditions. https://iopscience.iop.org/article/10.1088/1742-6596/1051/1/012021 https://iopscience.iop.org/article/10.1088/1742-6596/1051/1/...
lightsighter 7y ago
SF to Amsterdam is 5448 miles, which is 0.29 lightseconds, or 29ms at the speed of light, or about 2 frames of 60fps video, so 5X faster. :)
- pkroll 7y ago
  I'm shocked no one has pointed out .29 lightseconds is 290ms, not 29ms, and that you meant 0.029 lightseconds.
- rckoepke 7y ago
  Light in fiber optics travels 31% slower than the speed of light in a vacuum, and does not travel the ideal "great circle" route.
wincy 7y ago
Plenty of money to be made if you drill through the earth and run some fiber optics.
- rckoepke 7y ago
  Light travels 31% slower in fiber optic cables than it does in a vacuum. (Speed of light is only constant in a vacuum, not in arbitrary media). It can be faster to send the signal into space and bounce it off a satellite, than it would be through a perfect "great circle" surface fiber cable. This is the plan for SpaceX's Starlink constellation. Mark Handley makes an excellent series of YouTube videos explaining some of the high level engineering behind this with incredible visualizations[0] I like the napkin idea of a "great chord" optic cable as you seem to be suggesting (it's novel at least!) but temperatures get pretty hot very quickly when drilling down. At 5km depth you're already hitting 170C/340F, otherwise 10km is 375C and definitely a hard limit. Most fiber optic cable has a melting point of 70C, way under this. Keeping a maximum 6km depth (already way past the melting point of fiber cable), you can drill a perfectly straight line connecting two points on the surface of the earth that are 555.89 km apart. The horizontal tunnel will be 555.71 km long. Mainly this is because the earth is ~13,000 km diameter, so 6km depth is truly negligible. This tunnel would cost ~$1.2 Trillion for a 0.32% distance savings. Additionally, the speed of light in fiber slows down as the fiber increases in temperature. So you'll actually probably get significantly long ping, even though the signal is traveling an insignificantly shorter distance. [1] Lastly, Rayleigh scattering (primarily, as well as Raman and Brillouin scattering) increases with respect to temperature. This means the signal won't go as far as it does at surface conditions. 0: https://www.youtube.com/channel/UC-k1j7M2-hBfXeECd9YAQ_g/videos https://www.youtube.com/channel/UC-k1j7M2-hBfXeECd9YAQ_g/vid... 1: https://accelconf.web.cern.ch/accelconf/d09/papers/tupb35.pdf https://accelconf.web.cern.ch/accelconf/d09/papers/tupb35.pd...
  - deleted 7y ago
    [deleted]
  - paranoidrobot 7y ago
    Another idea was to use beams of Neutrinos and go point-to-point. It's been demonstrated[1] already. [1] https://physicsworld.com/a/neutrino-based-communication-is-a-first/ https://physicsworld.com/a/neutrino-based-communication-is-a...
    - rckoepke 7y ago
      Thank you for sharing this!
  - nkurz 7y ago
    > Most fiber optic cable has a melting point of 70C This seems very unlikely, or at least unlikely to be relevant. The type of fiber optic cable that melts at 70C is PMMA acrylic plastic. To my understanding, this type of fiber not used for long distance communication. Instead, glass fibers with lower losses(which happen to have a much higher melting point) are used: "Because of these properties silica fibers are the material of choice in many optical applications, such as communications (except for very short distances with plastic optical fiber)" (https://en.wikipedia.org/wiki/Optical_fiber https://en.wikipedia.org/wiki/Optical_fiber). Do you know more than my limited Wikipedia level of understanding, and are confident in saying that long haul cables indeed have a 70C melting point, or should you perhaps include a few more caveats on your napkin math?
    - rckoepke 7y ago
      I mean, it's napkin math right? The idea is to see if it's worth doing actual calculations. Even oil companies can't drill deeper than 10km in most areas because the heat destroys any material drill, even the most durable ceramics and exotic alloys that they have tested. If you can't drill a hole you cant put any kind of fiber in it. It doesn't matter if it's 5km deep, 10km, or even 20km. You'd need an order of magnitude more depth at minimum to make a difference (geometrically, because the Earth is 12 megameters in diameter), not a counting number multiplier more depth. That was more the point...it doesn't matter if the numbers are off by a factor of 2 or 3x, it's not worth the calculation time. If we got within 2-3x then the napkin math would have told us "go deeper, find more accurate/precise numbers for each parameter and consider edge cases". Instead this napkin math said: Forget it. Do something else. You'll never drill deep enough to make a difference. If, eventually, signals go through fiber at 0.98c instead of 0.7c, then it may be worth considering again despite the tremendous cost, because you could beat NYC-London HFT trades. But today, sattelites with lasers will be much faster than any drillable hole with fiber.

PeterCorless 7y ago

You can if you make the Planck constant a variable. People are postulating it just might be under the right conditions. https://iopscience.iop.org/article/10.1088/1742-6596/1051/1/012021 https://iopscience.iop.org/article/10.1088/1742-6596/1051/1/...

lightsighter 7y ago

SF to Amsterdam is 5448 miles, which is 0.29 lightseconds, or 29ms at the speed of light, or about 2 frames of 60fps video, so 5X faster. :)

pkroll 7y ago
I'm shocked no one has pointed out .29 lightseconds is 290ms, not 29ms, and that you meant 0.029 lightseconds.
rckoepke 7y ago
Light in fiber optics travels 31% slower than the speed of light in a vacuum, and does not travel the ideal "great circle" route.

wincy 7y ago

Plenty of money to be made if you drill through the earth and run some fiber optics.

rckoepke 7y ago
Light travels 31% slower in fiber optic cables than it does in a vacuum. (Speed of light is only constant in a vacuum, not in arbitrary media). It can be faster to send the signal into space and bounce it off a satellite, than it would be through a perfect "great circle" surface fiber cable. This is the plan for SpaceX's Starlink constellation. Mark Handley makes an excellent series of YouTube videos explaining some of the high level engineering behind this with incredible visualizations[0] I like the napkin idea of a "great chord" optic cable as you seem to be suggesting (it's novel at least!) but temperatures get pretty hot very quickly when drilling down. At 5km depth you're already hitting 170C/340F, otherwise 10km is 375C and definitely a hard limit. Most fiber optic cable has a melting point of 70C, way under this. Keeping a maximum 6km depth (already way past the melting point of fiber cable), you can drill a perfectly straight line connecting two points on the surface of the earth that are 555.89 km apart. The horizontal tunnel will be 555.71 km long. Mainly this is because the earth is ~13,000 km diameter, so 6km depth is truly negligible. This tunnel would cost ~$1.2 Trillion for a 0.32% distance savings. Additionally, the speed of light in fiber slows down as the fiber increases in temperature. So you'll actually probably get significantly long ping, even though the signal is traveling an insignificantly shorter distance. [1] Lastly, Rayleigh scattering (primarily, as well as Raman and Brillouin scattering) increases with respect to temperature. This means the signal won't go as far as it does at surface conditions. 0: https://www.youtube.com/channel/UC-k1j7M2-hBfXeECd9YAQ_g/videos https://www.youtube.com/channel/UC-k1j7M2-hBfXeECd9YAQ_g/vid... 1: https://accelconf.web.cern.ch/accelconf/d09/papers/tupb35.pdf https://accelconf.web.cern.ch/accelconf/d09/papers/tupb35.pd...
- deleted 7y ago
  [deleted]
- paranoidrobot 7y ago
  Another idea was to use beams of Neutrinos and go point-to-point. It's been demonstrated[1] already. [1] https://physicsworld.com/a/neutrino-based-communication-is-a-first/ https://physicsworld.com/a/neutrino-based-communication-is-a...
  - rckoepke 7y ago
    Thank you for sharing this!
- nkurz 7y ago
  > Most fiber optic cable has a melting point of 70C This seems very unlikely, or at least unlikely to be relevant. The type of fiber optic cable that melts at 70C is PMMA acrylic plastic. To my understanding, this type of fiber not used for long distance communication. Instead, glass fibers with lower losses(which happen to have a much higher melting point) are used: "Because of these properties silica fibers are the material of choice in many optical applications, such as communications (except for very short distances with plastic optical fiber)" (https://en.wikipedia.org/wiki/Optical_fiber https://en.wikipedia.org/wiki/Optical_fiber). Do you know more than my limited Wikipedia level of understanding, and are confident in saying that long haul cables indeed have a 70C melting point, or should you perhaps include a few more caveats on your napkin math?
  - rckoepke 7y ago
    I mean, it's napkin math right? The idea is to see if it's worth doing actual calculations. Even oil companies can't drill deeper than 10km in most areas because the heat destroys any material drill, even the most durable ceramics and exotic alloys that they have tested. If you can't drill a hole you cant put any kind of fiber in it. It doesn't matter if it's 5km deep, 10km, or even 20km. You'd need an order of magnitude more depth at minimum to make a difference (geometrically, because the Earth is 12 megameters in diameter), not a counting number multiplier more depth. That was more the point...it doesn't matter if the numbers are off by a factor of 2 or 3x, it's not worth the calculation time. If we got within 2-3x then the napkin math would have told us "go deeper, find more accurate/precise numbers for each parameter and consider edge cases". Instead this napkin math said: Forget it. Do something else. You'll never drill deep enough to make a difference. If, eventually, signals go through fiber at 0.98c instead of 0.7c, then it may be worth considering again despite the tremendous cost, because you could beat NYC-London HFT trades. But today, sattelites with lasers will be much faster than any drillable hole with fiber.