Neutrinos travel straight through earth at the speed of light. Therefore, it seems that they could be great for intercontinental communication. Of course, I assume a lot still needs to be learned about detecting, producing and controlling neutrinos before they can be used for the practical purpose of communication.
My question: In principal, could neutrinos be manipulated similarly to radio waves for the purpose of communication? I mean, modulation, filtering, etc. ?
We already know a lot about detecting, producing and controlling neutrinos.
Production in a controllable (switchable) way requires a particle accelerator. Enormous energy is not required but high current is. These are complex and expensive facilities. There are not something you can buy off-the-shelf.
Likewise detection requires large devices (tons to megatons of active volume, depending) simply because the neutrino--nucleon cross-section is insanely small at achievable energies. Again these are very complex and expensive devices (not the least because they are individually designed, constructed and tuned).
It also requires a team of experts to keep both the beam and the detector on-line.
The technical challenges are considerable, and the use cases for which the extra cost can be justified are almost certainly non-existent.
Radio waves normally transmit information by amplitude or frequency modulation. This assumes there is a carrier wave that can be modulated, and as twistor59 says in his comment, creating a carrier wave using neutrinos would be very difficult.
However many radio and TV stations are already streamed digitally, and in principle neutrinos could be used for this. I say in principle because, as you say in your question, neutrinos interact too weakly for this to be possible in the near future.
In the fall of 2000, Dr. Joseph Weber of Weber bar gravity wave detector fame delivered a presentation before an international group of satellite engineers in the Reiger auditorium of the former Comsat laboratories in Clarksburg, MD.
He told us that he had developed an ultra-sensitive neutrino detector that was basically a large (palm sized) crystal of pure silicon set inside of a NMR (nuclear magnetic resonance) imaging device. He said that the effect of the nearly perfect silicon lattice was to make the cross section susceptible to neutrino detection larger, and that if a neutrino should strike a single atom in the silicon crystal lattice, they would all vibrate in a manner that he could detect with the NMR setup. So, according to Joe, it was relatively easy for him to detect neutrinos, and all we needed to do was to come up with a way to modulate a beam of neutrinos, and satellite telecommunications would become obsolete overnight.
I told a neutrino physicist (a former assistant to Nobel Laureate Ray Davis) about Joe's ideas about neutrino detection. Jack told me that the idea was not original with Joe, and that it did not work. Furthermore, Joe's Weber bars never detected a single confirmed instance of gravity wave either. Neither has LIGO as yet, so there's no shame or blame here.
Be that as it may, the various methods for producing a beam of unmodulated neutrinos, even from facilities like CERN's LHC are pretty much ad hoc and slap dash (literally), from the descriptions I have read. Communication is really not their specialty nor the reason for constructing their facility. Neutrino communication on the order that Joe Weber envisioned will likely remain something that is in the realm of science fiction until we learn more about how better to produce and detect them.
