[RuggeroAltair]

Yes. One of the problem with that is unfortunately quite silly. We don't know the exact position of submarines, since the water interferes with the GPS-like systems and makes them unreliable, while neutrino beams need to be highly collimated to create a big enough flux.

[ajuc]

So we need neutrino-based GPS?

I wonder if we could create black hole out of protons and neutrons only (to make it possible to move this black hole with electrostatic field), make it the precise size that it will evaporate at the same rate that it will absorb particles from sun - so it will be stable, put it with driving mechanism and precise clock on the orbit around the sun to occlude for example 10x10 meters on the Earth, and move it with the driver to create CRT-like pattern at changing frequency - one period at X Hz, one at 100X Hz, repeat.

You can decode your position on earth based on time between the 2 holes in neutrino pulse.

Should I file for a patent?

[juiceandjuice]

A submarine can use dynamics and seafloor maps to know where it's at, I think he was alluding to the fact that it's harder for us to know where the submarine is at, and collimate the beam accordingly. Although, if the submarine could collimate the beam it could communicate it's location (which it should be able to know a little bit better than the base) to a base via collimated beam.

Also, you'd probably want at least one more black hole to even attempt a somewhat accurate 2d/3d fix :) I'd imagine VLF communications are probably good enough for now.