Talk:3053: KM3NeT

First groan! (Not that I don't appreciate it, but definitely the most groanworthy comic in a long while...) 172.69.195.229 17:59, 19 February 2025 (UTC) For future context, this array has risen in notoriety thanks to the recent detection of the highest energy neutrino yet, but sadly I need to take this occasion to note how the deadliest thing in the strait of Sicily are not superluminal alien fish, but human traffickers moving people on botched up vessels from the north African coast for the past fifteen years, often resulting in shipwrecks in the waters right above KM3NeT. --172.70.216.67 22:39, 19 February 2025 (UTC)

I heard about this last week from a BBC Podcast (Inside Science?). The telescope is only part complete*, and consists of photo-multipliers (can detect a single photon) in glass spheres on a string rising from the sea floor to create a 3D grid (as illustrated). As the decay results in further luminescent particles the direction can be determined and the muon was travelling tangentially to the surface. *As with LIGO, the observation was made when the facility wasn't fully commissioned, so they had to carefully check for other light sources (possible joke source) that they weren't being 'swallowed' by bioluminecence? RIIW - Ponder it (talk) 08:13, 20 February 2025 (UTC)

So... excuse my naivité, but how do they, in reality, ensure bioluminescent fish are not confusing the neutrino detectors? 162.158.155.101 19:33, 20 February 2025 (UTC)

As it depends upon a 'track' of light, you can work out how likely it is that a set of bioluminescent fish happened to spontaneously 'flash' (in a line, in sequence and at a superluminal velocity for the medium) that coincidentally looks like the non-fish detection signature that they're looking for. (That and/or other factors, looking for particular wavelengths, without known bioluminescent sources, etc.) 172.69.195.229 20:54, 20 February 2025 (UTC)

They just discount anything that looks a bit fishy.172.71.178.78 09:31, 21 February 2025 (UTC)

Cerenkov radiation, at any time, looks like a giant cone with the tip at the position of the generating particle. So I assume they can track the progress of the detections with time and dismiss anything that's not compatible with that geometry and time dependency. Nomentz (talk) 15:34, 21 February 2025 (UTC)

You can't 'see' the cone, in the way the diagram indicates, but you could infer it from your exacting recordings of when the cone/piled-up-wavefront crosses your various detectors. And it is unlikely that a set of flashes happened, from separate but linearly-aligned sources, that happened to so similarly coincide into an identically constructive "shockwave of light"/'photonic boom'...

PS, you (and others, if interested) might like to use the ready-templated form of wikipedia linking that we have here, {{w|Cerenkov radiation}}, saving the effort of the 'full link'. Just paste any wiki page's major header in after the "w|". With, whenever necessary, the option of adding another "|" and text you want to appear instead of the straight page-title. (It has a flexibility regarding initial capitalisation, and adding a plural 's', or similar trivial suffix, after the {{}} shortcuts the need to do {{w|Singular|plural}} in most cases, and similar tricks. See how {{w}} is used in pretty much any Explanation source, and you might pick up more of the useful subtleties.) 172.70.160.216 22:28, 21 February 2025 (UTC)

Please,[citation needed] for "undersea life does not move at the speed of light"? It's mildly humorous, but in contrast to the mission of this site to EXPLAIN xkcd and just sheer ignorance, we do not need a cite for any life, undersea or not, travelling at less than the speed of light! Cuvtixo (talk) 21:27, 20 February 2025 (UTC)

you may find it was added by a bot. 162.158.39.130 11:59, 21 February 2025 (UTC)

I feel that Randall missed a chance at a "Cherenkov Angle" pun in the title text 172.70.134.237 23:40, 20 February 2025 (UTC)

Woah! Was that a Dad Joke? 162.158.168.161 11:55, 21 February 2025 (UTC)

I don't think that the explanation of the title text is incomplete (but I'm a Physicist with a diploma); which part do you want to be explained further? Nomentz (talk) 15:25, 21 February 2025 (UTC)

Looking at the revision history, it appears there's a glitch in the matrix. The incomplete tag was removed, nobody reinstated it, but then several edits later it reappears in the pre-edit version.141.101.99.69 16:50, 21 February 2025 (UTC)