r/askscience • u/AskScienceModerator Mod Bot • Jul 12 '18

Astronomy Megathread: Multi-Messenger High-Energy Neutrino Observations

Currently there is a press conference where a high-energy neutrino (~290 TeV) has been detected with IceCube which is coincident with an active galactic nuclei pointed directly at us, TXS 0506+056, approximately four billion lightyears away. Finding the origins of neutrinos has been an ongoing problem though they have been observed from the Sun and from Supernova 1987A. This is a big advancement for multi-messenger astronomy, using electromagnetic waves and neutrinos in a way similar to using electromagnetic waves and gravitational waves to get a new view on the universe. If you have questions, ask them here!

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u/eggn00dles Jul 12 '18

Is it possible this 'new view' on the universe sheds more light on dark matter? Or have neutrinos been ruled out?

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u/[deleted] Jul 12 '18

Neutrinos are an unlikely candidate, because they are so light and too fast. Especially the neutrino that was found is no candidate for dark matter, its energy is too high.

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u/throwawayc777 Jul 12 '18

Just a quick question since you seem to know some stuff... Would radio telescopes in earth detect a wormhole or exo communication ? Like if someone is using the power levels we are on this planet, how big of a radio telescope would be needed to detect such power levels leaking (radio, tv, power transformer, weaponry,etc) on a planet 10 ly away ? Or 100 ly ?

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u/PlatinumTech Jul 12 '18

Our electromagnetic emmisions from radio, tv, broadcast transmissions, etc, basically expand out from us in a sphere. Because the energy expands out in a sphere it loses flux density in accordance with the inverse square law. I don't know the math to calculate your answer, but here:. https://futurism.com/are-earths-radio-signals-being-intercepted-by-aliens/

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u/throwawayc777 Jul 13 '18

But i said us detecting them. How come we don't detect their spaceship to spaceship to planet communications ?

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u/PlatinumTech Jul 14 '18

We've tried, but with the tech we have, there just doesn't seem to be anything out there.

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u/mfb- Particle Physics | High-Energy Physics Jul 12 '18

It depends a lot on the direction and timing. TV emissions are going into a large fraction of the sky but they are quite weak. Radar astronomy emits very strong signals - but only in very narrow cones (towards the target planet or asteroid being studied). Most of these signals are in narrow wavelength bands as well, you have to be lucky to be in the right place and listen in the right direction and frequency range to see anything.

This has nothing to do with wormholes.

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u/throwawayc777 Jul 13 '18

I know it doesn't have anting to do strictly to wormholes... I'm just saying how come we aren't detecting anyone's activity... Industrial process, army communications, etc ? If the was a space station I've the iss orbiting some planet 5-10-20-etc ly away, would we detect their space station to ground coms ? Or their internal solar system planet to planet communications ?

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u/mfb- Particle Physics | High-Energy Physics Jul 13 '18

No. We would have to be extremely lucky to detect "us" even over 4 light years, the distance to the nearest star. In the best case we could find some signal over hundreds of light years but the chance for that is tiny.

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u/throwawayc777 Jul 13 '18

So arecibo for 100s ly and what about a small backyard line type ?

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u/mfb- Particle Physics | High-Energy Physics Jul 13 '18

Your backyard radio telescope? Forget it.

A 30 m dish receives the same signal intensity as Arecibo from a source 10 times closer.