Would there be any good reason or theoretically practical way to use neutrinos for communication?
Asking because in 3 Body Problem it’s seen as a “civilized” way to communicate compared to radio waves.
Asking because in 3 Body Problem it’s seen as a “civilized” way to communicate compared to radio waves.
Not impossible, but likely this amount of orbital lift capacity is better used for other projects.
It's one of those cases where "just" really does apply. IR remote controls work this way, using a slow bitstream to key a 40 kHz carrier that drives the IR LED. Scientific applications that need even greater sensitivity can take advantage of the fact that the expected phase of the carrier is known as well as its frequency. Devices called lock-in amplifiers are used to run a wide variety of experiments and processes using that principle.
Doing this stuff with neutrinos rather than photons, however, is one of those * * * * * exercises that the textbook authors put in as a joke.
One follow up question. When reading about low-light cameras, the number of photons per pixel seem much smaller. I guess the following factors are involved:
Several orders of magnitude reduction under low light.
Pixel area likewise much smaller than thumb.
Exposure time less than a second.
Visible light vs. all spectrum.
Well, the question: Do the numbers fit? :-)
"Casper said that there have only been about 10 observations of tau neutrinos in all of human history but that he expects his team will be able to double or triple that number over the next three years."
This is not to say that it's _easy_ to detect the other kinds, you still need a large number of neutrinos and a large volume for detection. The example that always comes up is submarine communication - which has two problems - detecting a sparse and intermittent signal to get a useful bitrate out, and generating a beam of sufficient intensity to begin with, let alone a beam that is steerable!
How about astrophage? :)
Seems like the exact opposite qualities of something you'd want to use for communication.
If you use radio waves that travel around the earth, the shortest distance they can travel is πR ≈ 20,000km.
If you use neutrinos that travel through the earth, the shortest distance is 2R ≈ 12,700km.
So the advantage is about 7,300km (or in time units, 25ms ≈ 7,300km / (the speed of light))
> As opposed to how we communicate now globally?
From this interaction I thought you'd missed the point that "send messages through the earth" is something we're currently not doing. Of course you're right that the "if there were a way to reliably detect neutrinos" is doing a lot of work.
If you want a book written by someone who knows some real physics, read The Clockwork Rocket by Greg Egan. He changed one simple law of physics, worked out the consequences for quantum mechanics and relativity, made up some plausible–enough biology, and wrote a series of books in the resulting universe. The characters in the book have to discover or teach each other those laws, so the book is actually a pretty decent way to learn something of the laws of our own universe too. He wrote a huge amount of supplementary material as well, going into all the details. Truly an astounding accomplishment.
I feel like quantum entangled communication would be a better direction to head. Not that they’re mutually exclusive development paths.
> Neutrinos have many properties that would make them superior even to the extremely low radio frequencies. Because neutrinos are nearly unaffected by matter, a neutrino beam could traverse directly through the earth from the transmission site to the submarine. A directional beam would allow confidential information to be passed only to the intended recipient. Neutrino communications would also be totally jam-proof. As an additional benefit, a neutrino message could be received in the deepest of waters, leaving a submarine less vulnerable to enemy attacks.
I mean it could all be strings, or quantum gravity, or Wolfram's crazy graph theory automatons, or maybe something else entirely.
We don't know.
The mass of the three quarks (one up quark and two down quarks) making up a neutron is only about 1% of the mass of a neutron. The rest of the mass comes from strong nuclear force interactions via gluons which are themselves massless.
There was a lot of media hype about 'the god particle' that doesn't really translate into reality. I've said this in another comment, but if you add up the mass of the constituent quarks of a neutron, you get approximately 1% of a neutron's mass. The majority of the mass comes from interactions with strong nuclear force which are mediated by gluons, which are themselves massless.
There is no current agreed upon understanding of quantum gravity or if gravitons exist. I think the big contenders right now are String Theory (which seems to be having issues progressing in a way that is useful) and loop quantum gravity, but there are a lot more theories than that.