There has been a lot of progress in the past 20 years on antineutrino detection. Antineutrinos are produced by fission and so there's been a fair bit of intere

There has been a lot of progress in the past 20 years on antineutrino detection. Antineutrinos are produced by fission and so there's been a fair bit of interest in detecting them to detect covert nuclear tests as well as potentially a new modality of detecting nuclear submarines. I think it could become possible before too long to use this to transmit data. It would probably be a ~billion dollar project, but the HFT arbitrage market is essentially winner-take-all, and may be large enough to support this size investment.