Hacker News Reader

Comment by hyperionultra | Hacker News Reader

What is practical application of Francis work?

It could be the beginning of Neutrino astronomy [1]. So far, we only used the electromagnetic spectrum, from radio waves to gamma rays, to observe the universe. If we could equally leverage neutrinos or gravitational waves, we could observe much more of the universe. For example, the cosmic microwave background radiation enables us to deduce the conditions at 300ky after the Big Bang. The cosmic neutrino background [2] could give us insight in the conditions 1s after the Big Bang.

[1] https://en.wikipedia.org/wiki/Neutrino_astronomy

[2] https://en.wikipedia.org/wiki/Cosmic_neutrino_background

The million dollars. A Nobel prize is worth a million dollars.

Similar to the Millennium prize by the Clay institute, the amount of luck and effort you need to receive the prize don't make it worthwhile. Plus, it's generally expected to use that money for further research. It would be advisable to focus on other endeavors, if money is your motivator.

So, two years salary in the Bay Area where it's a lot warmer?

Neutrino detectors are essential in receiving communication from other galaxies.

That doesn't make any sense. Photons would work much better.

Photons work better for driving a car too but being able to hear is still quite useful.

In other words: we already have lots of things that measure photons. You see things on two totally different media it's a lot more compelling than just one.

That may be the case, but it doesn't explain why neutrinos would be essential for intergalactic communication. Maybe the person I was responding to didn't realize neutrinos travel very close to the speed of light, not infinitely fast?

Neutrinos might be a better medium for intergalactic communication, since they can travel through most objects.

Or we can all just think big thoughts at the same time... https://en.wikipedia.org/wiki/Calling_Occupants_of_Interplan...

There isn't anything in the way that would require this. I mean, we can see back to (shortly after) the Big Bang.

Kind of contrived, but if you're sending a signal from some other planet to our planet, depending on the geometry, there will be times of the year that our local star is in the way of photons.

Also, if you're sending out photons from a planet, chances are there's a local star nearby. Stars tend to be a broad-spectrum photon source, which is going to make it tough for receivers to decode the intentional signal.

Which is more difficult:

(1) Putting a telescope in space

(2) Focusing and detecting very high energy neutrinos

This is especially the case when photons will have, what, 15 orders of magnitude less energy than the neutrinos?

> Which is more difficult:

This is why I always search for my keys under the streetlamp, even though I dropped them in the unlit field nearby.

That said, putting a telescope in space is easy; we've done it several times...

But, can we filter photons intentionally sent from some far off solar system out of the stream of photons coming from their local star?

Yes. It's been proposed for SETI inside our galaxy too, and could be done with current technology (at least, receiving).

It would be VASTLY easier than using neutrinos.

Neutrinos are not an analog to sound in the point you are trying to make. They are many orders of magnitude more weakly interacting and much, much difficult to measure.

Knowing the properties of neutrinos is essential for building the neutrino bomb, the most ethical weapon possible.

Reply on news.ycombinator.com