9 ms·
Record-breaking neutrino is most energetic ever detected
- cylinder714 2y agoThe article references the "Oh-My-God particle, the most energetic particle yet encountered. Here's the late John Walker's excellent piece on that: https://fourmilab.ch/documents/OhMyGodParticle/ https://fourmilab.ch/documents/OhMyGodParticle/
- epistasis 2y ago> These calculations involve some elementary but easy to mess up algebra and some very demanding numerical calculations for which regular IEEE double precision is insufficient. If you'd like to double-check these results, be sure to use a multiple precision calculator with at least 30 significant digits of accuracy. So you're saying my iPhone built-in calculator app is going to have problems....? Time to whip out dc on the terminal.
- jiggawatts 2y agohttps://www.wolframalpha.com/ https://www.wolframalpha.com/
- Onavo 2y agoOr ChatGPT to output Julia code
- fambalamboni 2y ago[dead]
- thunkingdeep 2y ago[flagged]
- Onavo 2y ago> Which defaults to float64, which is IEEE precision, exactly what the article warns about…… I mean, seriously? It has native support for arbitrary precision operations. RTFM.
- thunkingdeep 2y ago[flagged]
- eq_ind 2y ago> So you're saying my iPhone built-in calculator app is going to have problems....? Your Android phone's built-in calculator app, however, will not. :^) https://dl.acm.org/doi/pdf/10.1145/3385412.3386037 https://dl.acm.org/doi/pdf/10.1145/3385412.3386037
- pixelpoet 2y agoThat was indeed excellent reading, thank you.
- pfdietz 2y agoIf I understand correctly, the interaction length of such an energetic neutrino in rock is only in the tens of kilometers.
- jihadjihad 2y agoThe Nature paper itself can be found here [0], for those curious. Was just published today. 0: https://www.nature.com/articles/s41586-024-08543-1 https://www.nature.com/articles/s41586-024-08543-1
- ziddoap 2y agoArs Technica has an article, as well, with some additional context/explanation. https://arstechnica.com/science/2025/02/most-energetic-neutrino-yet-seen-smashes-through-seafloor-detector/ https://arstechnica.com/science/2025/02/most-energetic-neutr... And an interesting, somewhat related, video from PBS Space Time exploring how supernovas act as particle accelerators (but don't quite explain particles like this one or the 'Oh My God' particle): https://www.youtube.com/watch?v=2sSNWIJbV3Q https://www.youtube.com/watch?v=2sSNWIJbV3Q
- dr_dshiv 2y agoNeutrinos “interact with regular matter so rarely that it's estimated you'd need about a light-year of lead to completely block a bright source of them. Every one of us has tens of trillions of neutrinos passing through us every second, but fewer than five of them actually interact with the matter in our bodies in our entire lifetimes.” They have 1/500,000 the mass of electrons. They interact only through the super short range weak force (and gravity). Nearly 5% of fission energy is expressed in neutrinos. And, they may be their own antiparticles, meaning they can potentially annihilate each other. Wild that these things can carry so much energy!
- ricksunny 2y ago>Every one of us has tens of trillions of neutrinos passing through us every second, but fewer than five of them actually interact with the matter in our bodies in our entire lifetimes.” Oh, but those five...
- lubujackson 2y agoNext time I trip over nothing I am blaming those "darn neutrinos messing up my knee!"
- cozzyd 2y agoThe funny thing is a km^3 scale detector like km3net or icecube has roughly the same mass as all humans combined
- insane_dreamer 2y agoalso reported in the NYT: https://www.nytimes.com/2025/02/12/science/astrophysics-universe-neutrinos.html https://www.nytimes.com/2025/02/12/science/astrophysics-univ...
- antognini 2y agoFor context, 120 PeV is about 10% the kinetic energy of a ping pong ball during typical play.
- lnauta 2y agoOne of the lead researchers in KM3NeT mentioned that the particle was emitting 2 horse power in light during detector transit. A typical body builder expends about 1 horse power while performing, so its 2 body builders in a single particle.
- A_D_E_P_T 2y ago> typical body builder expends about 1 horse power while performing Close, but ackshually... Bodybuilders just oil up and pose in beauty pageants. 1 horsepower is basically one 250-pound bench press in one second. (550 foot pounds of work; the aforementioned bench press assumes a 2.2-foot stroke length.) Most bodybuilders and serious weight lifters can do that, but they can't keep it up for long.
- 01HNNWZ0MV43FF 2y agoIt must have been a very short amount of time. 2 HP is 1,500 watts, probably more light than all lightbulbs in my house combined.
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- ziofill 2y agoIt's mentioned in the article that the highest energy ever recorded for a single particle was 320,000 PeV which is about 50 joules, i.e. the energy of a golf ball at 100 mph @_@
- queuebert 2y agoThat was a cosmic ray proton, which has probably 10 billion times the mass of a neutrino and interacts much more strongly with normal matter. A nuclear juggernaut vs a ninja by comparison.
- cozzyd 2y agoMost likely a heavier nucleus than a proton too
- adaml_623 2y agoWould a nucleus composed of multiple nucleons stay stuck together with that much energy? If it's zipping along and not interacting with the anything then sure but how did it get that much energy in the first place?
- cozzyd 2y agoYes, while there is a large amount of uncertainty, it is believed they the majority of the highest energy cosmic rays are nuclei of elements like iron. For people like me, in the business of finding high energy neutrinos (I'm not involved in km3net, btw), that's a bad thing since that means the highest energy cosmic rays convert less efficiently into neutrinos when interacting with the cosmic microwave background. How they got so much energy in the first place is kind of an open question. Generally it involves magnetic fields and shock fronts, getting a little kick each time (but yes, you also have to avoid disintegrating the nucleus in the acceleration environment!)
- dooglius 2y agoIt looks like they detected a muon and are inferring a neutrino from the fact it went through a lot of solid. Couldn't it be any other weakly-interacting particle though?
- Sniffnoy 2y agoHow? Quarks can't change into leptons. Charged leptons can't change directly into other charged leptons. And neither charged leptons nor hadrons are going to pass through such a quantity of matter, as you say. I mean I assume other cases are technically possible but they don't seem very likely...
- deleted 2y ago[deleted]
- nxpnsv 2y agoNothing else that we know of would create a muon of that energy deep inside bedrock.
- AnimalMuppet 2y agoNit: As I read the article, they aren't sure that it went through any solid. Went through a lot of seawater, though. And your argument still applies.
- cozzyd 2y agoIt could be beyond the standard model physics but no other standard model particle could work other than a neutrino.
- yapyap 2y agobit of a redundant title
- ge96 2y agoWhat's faster than satellite communication? Neutrinos baby Not even sure if that's worth doing, either create/emit or use encode data into them as they fly by to be received by someone else Edit: that's cool people have tried though
- queuebert 2y agoNeutrinos can go straight through the Earth, yes, but since they have mass their velocity is less than c.
- mr_toad 2y agoIt’s very close to c though, close enough that it beats sending a signal around the Earth. The drawback is the impractical size and cost of a receiver.
- shagie 2y agoThat's covered in RFC 1217. https://www.rfc-editor.org/rfc/rfc1217.html https://www.rfc-editor.org/rfc/rfc1217.html Its in section 4: Jam-Resistant Underwater Communication
- PaulHoule 2y agoWould have really been faster if this result was true https://en.wikipedia.org/wiki/2011_OPERA_faster-than-light_neutrino_anomaly https://en.wikipedia.org/wiki/2011_OPERA_faster-than-light_n... which was something that would have happened in https://en.wikipedia.org/wiki/Steins;Gate https://en.wikipedia.org/wiki/Steins;Gate Funny the idea that the neutrino might be a tachyon never seems to go away. The best fit of OPERA results is within error bars of the speed of light but towards the superluminal side. Superluminal neutrinos of the energy they were generating with the kind of mass we expect wouldn't be going measurably faster than the speed of light. I visited the site of this experiment https://permalink.lanl.gov/object/tr?what=info:lanl-repo/lareport/LA-UR-97-2534-07 https://permalink.lanl.gov/object/tr?what=info:lanl-repo/lar... where the best fit for the squared mass was just a tiny bit negative but within bounds of zero. There is the classic 1985 Chodos paper https://www.academia.edu/27606971/The_neutrino_as_a_tachyon?uc-sb-sw=11109336 https://www.academia.edu/27606971/The_neutrino_as_a_tachyon?... and people still keep writing papers about it https://www.mdpi.com/2073-8994/14/6/1172 https://www.mdpi.com/2073-8994/14/6/1172 somebody is going to have to measure a positive mass squared to really put a stake in its heart.
- bookofjoe 2y ago>Observation of an ultra-high-energy cosmic neutrino with KM3NeT https://www.nature.com/articles/s41586-024-08543-1 https://www.nature.com/articles/s41586-024-08543-1
- neals 2y agoAnybody here able to tell me what it means? Where do neutrinos get their energy from? Is there a limit? Will this make my phone smaller? My microwave quicker?
- scotty79 2y agoI can answer last two questions with definite "no".
- thamer 2y agoIt took a few tries, but I got Wolfram Alpha to compute its velocity compared to the speed of light[1]. I started with: sqrt(1-((1/(1+120 PeV / (neutrino mass * c^2)))^2)) but it simply said "data not available". So I changed: 120 PeV to 120e15 * 1.602176634e-19 kg m^2 s^-2 neutrino mass to 1.25e-37kg speed of light to 299792458 m/s and finally it gave a numeric result: 0.999999999999999999999999999999999999829277971 (that's 36 nines in a row). Pasting it in Google says the value is "1", which is… not far off. If you want details about the way this is calculated, I dug up the formula from an article I'd written about particle velocities in the LHC, back in 2008[2]. For comparison, their 7 TeV protons were going at 0.999999991 × c. [1] https://www.wolframalpha.com/input?i=sqrt%281-%28%281%2F%281%2B%28120e15*1.602176634e-19+kg+m%5E2+s%5E-2%29+%2F+%281.25e-37kg++*+%28299792458+m%2Fs%29%5E2%29%29%29%5E2%29%29 https://www.wolframalpha.com/input?i=sqrt%281-%28%281%2F%281... [2] https://log.kv.io/post/2008/09/12/lhc-how-fast-do-these-protons-go https://log.kv.io/post/2008/09/12/lhc-how-fast-do-these-prot...
- davrosthedalek 2y agoWe don't know the neutrino's masses, so this is a lower limit for v (since the mass you used is an upper limit)
- wd776g5 2y agoI can see it came from your source but why is the neutrino mass specified in kg instead of g? why not 1.25e-34g?
- thamer 2y agoThe kilogram is the base unit of mass in the International System of Units (SI): https://en.wikipedia.org/wiki/SI_base_unit https://en.wikipedia.org/wiki/SI_base_unit Time is in seconds, length in meters, temperature in kelvin, etc. A unit of energy like a joule is then defined using these base units, so 1 joule is 1⋅kg⋅m^2⋅s^-2.
- skissane 2y ago> The kilogram is the base unit of mass in the International System of Units (SI) Arguably, an ugly wart, but one we are stuck with for historical reasons. The base units of the original metric system (metre and gram) were poorly proportioned for practical use, resulting in the two main scientific/engineering systems of metric units both choosing to prefix one base unit - the centimetre-gram-second (cgs) system chose to prefix the metre, the metre-kilogram-second (mks) system chose to prefix the gram, and eventually mks won out over cgs and evolved into SI. Whatever warts SI has, they are nothing compared to the chaos of the Imperial/customary system
- octocop 2y agoWhy do they place the receiver in a large body of water, like the Mediterranean?
- tjpnz 2y agoNeutrino interactions with nuclei of water produce charged particles which move faster than the speed of light in water (but slower than through a vacuum tube) creating a cone of light known as Cherenkov radiation, which is the optical equivalent to a sonic boom. This is projected onto a ring around the detector. Doesn't need to be submerged in a body of water as large as this. The Super-Kamiokande[0] detector for instance is located in a body of water inside a mountain. 0: https://en.m.wikipedia.org/wiki/Super-Kamiokande https://en.m.wikipedia.org/wiki/Super-Kamiokande