[HN Gopher] Ultrahigh-energy photons up to 1.4 PeV from 12 g-ray... ___________________________________________________________________ Ultrahigh-energy photons up to 1.4 PeV from 12 g-ray Galactic sources (2021) Author : gone35 Score : 19 points Date : 2022-02-13 20:12 UTC (2 hours ago) (HTM) web link (www.nature.com) (TXT) w3m dump (www.nature.com) | qwertyuiop_ wrote: | For laymen, can someone who is knowledge put this into | persepective ? | johndough wrote: | 1.4 PeV are about 0.224 millijoules or roughly an 8 billionth | of a phone charge, so not much really. However, the photons we | usually deal with are weaker by an unimaginable amount, but | also much more plentiful. For example, a 100 W light bulb emits | something in the order of 10^21 photons per second. If you had | a light bulb that emitted the same amount of photons with 1.4 | PeV each, you'd have a device equivalent to one Tsar bomb (the | most powerful bomb ever detonated in the history of mankind) | _every second_. | adhesive_wombat wrote: | That's a big old phone battery: 8 billion times 0.2mJ is a | 120000mAh 3.7V battery. | | But yes, it's in that ballpark and it's a loooot of energy to | pack into a proton. | contravariant wrote: | It's roughly the amount of kinetic energy in a single grain | of rice if you gently throw a handful of them. It's not much, | but it's not an inconceivably small amount of energy either. | | Comparing it to a phone charge is less useful because | batteries store _a lot_ of energy (especially when converted | to kinetic energy). | amluto wrote: | I would say that 1.4 PeV is enough energy (by a large | margin) to be audible. If that photon interacted with | something near you and deposited any respectable fraction | of its energy as heat or kinetic energy on a macroscopic | scale, you would hear it! | eesmith wrote: | https://en.wikipedia.org/wiki/Oh-My-God_particle might help. | _Microft wrote: | There is another, imo even better, page on this particle: | | https://www.fourmilab.ch/documents/OhMyGodParticle/ | adhesive_wombat wrote: | At 320 EeV, the OMG particle is over 5 orders of magnitude | more than 1.4 PeV. It's a completely nuts amount if energy to | have in a single particle: about the same as a decently | moving baseball. From the particle's frame, it takes only a | day to go a billion light years. | ipdashc wrote: | > about the same as a decently moving baseball | | I heard this, but it's hard to believe it's real (or, | obviously, I'm misunderstanding it). What would happen if | one of these hit a person in space? Would it be the same | sort of feeling as getting hit by a baseball? | | Earlier I wondered how this much energy didn't totally | wreck the detector, but someone else posted this link | https://www.fourmilab.ch/documents/OhMyGodParticle/, which | says "The Fly's Eye consists of an array of telescopes | which stare into the night sky and record the blue flashes | which result when very high energy cosmic rays slam into | the atmosphere". So the protons don't actually hit the | detector. That makes more sense. | adhesive_wombat wrote: | It doesn't interact like a baseball, it just has the | energy of one. | | If it does hit an atom, it produces a shower of other | particles, most of which will have similarly huge | energies and will probably go right through the rest of | the detector and start their own showers in other matter. | So you'll get a detector with a few atomic dislocations, | and the rest of the energy would be distributed amongst a | huge number of other interactions. | | It's actually similar to x-ray "hardening", where soft | x-rays are filtered out by a metal shield, leaving only | harder radiation. This is carefully calibrated to allow | the radiation to penetrate to a certain depth, leaving | shallower tissue unharmed. | | In a way, it could be better to be hit by an OMG particle | than a less energetic particle, as the amount of energy | that gets dumped into you is smaller: the vast, vast | majority of it would be shotgunned deep into the ground | under you, and only a very few molecules in you are | actually affected. | planck01 wrote: | Its 100 times as much energy per photon than we as humans are | able to accelerate particles in the cern large hadron collider | with everything we have. It is a stupendous amount of energy | per photon. ___________________________________________________________________ (page generated 2022-02-13 23:00 UTC)