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ET Will Phone Home Using Neutrinos, Not Photons
KentuckyFC writes "Neutrinos are better than photons for communicating across the galaxy. That's the conclusion of a group of US astronomers who say that the galaxy is filled with photons that make communications channels noisy whereas neutrino comms would be relatively noise free. Photons are also easily scattered and the centre of the galaxy blocks them entirely. That means any civilisation advanced enough to have started to colonise the galaxy would have to rely on neutrino communications. And the astronomers reckon that the next generation of neutrino detectors should be sensitive enough to pick up ET's chatter."
This is exactly what Stanislas Lem wrote in "His Master's Voice" in 1968 :
http://en.wikipedia.org/wiki/His_Master's_Voice_(novel)
Indeed there are, every second, about 70 billion (7Ã--e10) solar neutrinos pass through every square centimeter on Earth. Even more to the point, unless we can come up with a wildly more efficient detector than current ones, because of those 70 billion in round numbers to the nearest billion 70 pass straight through and out the other side.
Encoding likely, hopefully binary. We'll have to figure out ET's communicative symbology after the pleasantry of exchanging "assumed to be universally consistent" math facts in whatever encoding. Then, assuming we can receive and decode, we have to try to understand ET's symbology with no common base. Then, we have to interpret ET's intent along with the message. Might take longer than the Fermi-labs mystery letter.
Invenio via vel creo
That part of TFS left me scratching my head. Since nothing short of a black hole or neutron star will actually stop neutrinos, and since every active star in the galaxy gives off neutrino radiation as a byproduct of stellar fusion, shouldn't the noise level be relatively high?
Apart from that, how exactly is this hypothetical neutrino comm generating its signal? Neutrinos are the byproduct of nuclear reactions, and you'd need to generate an awful lot for the signal to be heard over interstellar distances. Are they rapidly switching a fusion source on and off? Perhaps using matter and anti-matter instead? Either way, it'd be somewhat akin to blasting off hydrogen bombs in Morse code.
Final catch, if we don't know how a hypothetical neutrino comm would work, why would we assume it's feasible? I mean, if we're just going to handwave around the technical hurdles in generating a long range signal using exotic particles, why not go the extra mile and assume they're using gravity waves? Same benefits, equally difficult engineering problems.
Not that looking for neutrino signals isn't worth it - it costs us next to nothing to try it, and who knows, they might be right. However, there is a world of difference between "we should look for X in case it's used to contact us" and "they will contact us with X" which is the way the article is pitching it.
Erotic is when you use a feather. Exotic is when you use the whole chicken.
TFA mentions this problem, and pretty much rules out the possibility of using low energy neutrinos. A significant part of the paper is about picking just the right neutrino energy to communicate on.
Much Madness is divinest Sense --
To a discerning Eye --
Much Sense -- the starkest Madness
This is the fundamental problem, NOT noise sources, as earlier posts suggest. Although the sun produces large numbers, they are all low energy, less than 10 MeV. Supernovae aren't much bigger. As you go up in energy, astrophysical neutrinos both become more rare and easier to detect.
But 'easier' doesn't mean 'easy'. Even at high energies, you can only detect one in 10^20 or 10^30 neutrinos, even with detectors of order 1 kiloton. Detectors of order 1 megaton are feasable by current technology, but getting into the 10-100 megaton range means that you have to start instrumenting huge volumes of heavy matter, like the Great Lakes.
If you imagine aliens attempting to communicate over galactic distances, with resources such that they can turn a small moon into a 3D array of particle detectors, well, then maybe. A good science fiction story. But don't expect IceCube to be listening to alien Viagra commertials any day soon.
--Nathaniel, Experimental Neutrino Physicist
Yes, and if my grandma had subspace thrusters, she'd be a starship.
Perhaps you don't understand anything about neutrinos. They don't respond to electromagnetism, gravity, or the strong force. That means it's really hard to get a hold of them, like impossible.
So you can't use diffraction, reflection, refraction, or the other techniques for filtering and capturing objects.
And numerically there are a whole lot more neutrinos than photons. Like by a factor of 10^10 at least. That's nothing to sneeze at.
So a neutrino lens, or diffraction grating, or speed trap, or siphon, or spectrograph, or pinhole camera, they're all impossible unless we discover a new force of Physics.
Nyh
Of course they respond to gravity. Everything responds to gravity, with no exception whatsoever. Also, given that we now know for sure that neutrinos have mass, even from a Newton point of view it would be strange if they wouldn't respond to gravity.
The Tao of math: The numbers you can count are not the real numbers.