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."

His Master's Voice

[Anonymous Coward]

This is exactly what Stanislas Lem wrote in "His Master's Voice" in 1968 :

http://en.wikipedia.org/wiki/His_Master's_Voice_(novel)

Re:What about those from the sun?

[jabuzz]

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.

Encryption? Probably Not Intentionally...

[FurtiveGlancer]

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.

Noise free?

[RsG]

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.

Re:What about those from the sun?

[loimprevisto]

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.

Noise free but hard to detect

[DoctorNathaniel]

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

Re:Nuttier than fruitcakes

[Ancient_Hacker]

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.

   

Re:Speed of Light != Useless

[Nyh]

Back in the Roman Empire days, they could communicate with Rome using towers built on each others horizon. They then used light codes (similar to morse) to then relay information back to the Caesar.

Semaphore towers were only invented in the 18th century. The Romans used couriers on horse back to send written messages. And according to rhe Wikipedia: In about 35 AD, the Roman emperor Tiberius, by then very unpopular, ruled his vast empire from a villa on the Isle of Capri. It is thought that he sent coded orders daily by heliograph to the mainland, eight miles away.

Nyh

Re:Noise free?

[WilburCobb]

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

Even worse that that, neutrinos cannot be collimated like electromagnetic radiation by parabolic anthennas, since they almost don't interact with matter (I am talking about real science, not Star Trek). Therefore, those hydrogen bombs would spread neutrinos in all directions, so the signal would loose energy in proportion to the inverse square of distance.
Besides, how do you tune neutrino radiation so you can cut off the huge noise of neutrino star emissions? All of this is crackpottery, let's go back to the space elevator discussion.

Re:Nuttier than fruitcakes

[maxwell demon]

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.

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.