June 5, 2008

ET Phone Home: about neutrinos

(this entry is a translation from the original spanish version of this blog)

Yesterday reading slashdot I ran into a
paper (pdf) about some guys talking abount intergalactical communications (sounds like science fiction but basically they talk about very big distances across space) which as the communication medium use neutrinos.

To have a better understanding of what they were talking about I went back to read more carefully what neutrinos are, which types of neutrinos we can find, etcetera. Some history:

(NOTE: I discovered that physics papers like this one are very difficult to read for a newbie like me. I feel them like a 13th century narration about some sort of mathematical construction but ok then, must be their own style)


Neutrinos are from the
Los neutrinos son de la familia de los fermions family, which are very-very small particles, so small that they can penetrate any matter type (even smaller than photons).

So W. Pauli postulated the notion of "neutrino" so he could fix a math error in a formula while he was measuring the conservation of energy and momentum in beta decays (according to the wise Wikipedia, this is when as a result of a radioactive decay a beta particle -electron or positron- is expelled). He postulated (apparently) in order to describe a non-detected particle which was carrying the energy missing in his lab tests, measuring energy, momentum and angular momentum.
The name "neutrino" was given byE. Fermi but I will not go further on this since I haven't read anything.

Back to the paper. They first discuss which types of neutrinos are better for this type of communications, based on their signal/noise level acceptance. They also evaluate differently "energized" neutrinos (measured in eV, electronVolt - 1 MeV/c² = 1.783×10−30 kg, seems like in particle physics, quantum level, mass and energy are interchangeable, thanks to Einstein's work, so this measure is used as a mass unit and energy one).

One of the things they postulate is that the people from SETI which are a foundation which tries to explain life in the universe, doesn't find a single signal coming from the outer space (or further...) because information is no longer transmitted over photon-based channels or even bigger particles. Hence, since we (humans) don't have the technology needed to catch smaller particles we cannot listen to ET's family calls.

The paper the discusses how to code information (using neutrino's oscillation) whith neutrinos properties. It seems also that they propose some sort of super-neutrino-ray which works in a very high level of energy (or mass) but ok then, my super null-understanding of the topic doesn't allow me to go further.

I recommend you read the paper, I didn't finish it, and could understand some amount below 10% :D. But what I COULD, is to remember why I wanted to study physics after computer science. :D