4 ms·

Any thoughts on what it might feel like to get hit with this particle? I imagine the collision would turn into heat pretty quickly and the heat energy would con

by elil17 3y ago

Any thoughts on what it might feel like to get hit with this particle? I imagine the collision would turn into heat pretty quickly and the heat energy would conduct out from where you got hit and, if it was near any nerves, you might feel a warm spot on your body. Since energy scales with the square of velocity and momentum scales linearly with velocity, I can't imagine you would feel like you'd been hit by an object.

TooKool4This 3y ago
Wikipedia has it in the comparison. It’s more like getting punched. Really hard. https://en.m.wikipedia.org/wiki/Orders_of_magnitude_(energy) https://en.m.wikipedia.org/wiki/Orders_of_magnitude_(energy)
- KyleBerezin 3y ago
  Hmm, I think the effect would be more localized, and involve a lot of strange forms of matter. My guess is it would be similar to what happened to Anatoli Bugorski when he stuck his head into a proton beam.
- orangea 3y ago
  That doesn't mean getting hit by this particle would feel like a punch, since what you feel when you get punched is a transfer of momentum rather than a transfer of energy.
  - TooKool4This 3y ago
    Yep but just an easy first approximation since the article didn’t have any numbers on the momentum of the particle. I’m sure if you wanted a really good answer you would need more than momentum and actually need to analyze the products of the collision like another poster suggested. Also wanted to share this table since energy expressed in eV sounds like big numbers but it’s nice to understand that the definition of the eV is small in our usual definition of energy.
- petercooper 3y ago
  So I'm confused. If some specific relatively small devices (relatively to the size of the Earth) managed to pick up several of these over the years, surely some of these are hitting people? Are people randomly feeling like they got impacted (if not punched, as per a sister comment) out of nowhere? Apologies if this is a ridiculous question; physics was always my weak suit.
  - orangea 3y ago
    If you got hit by one of these then you wouldn't feel anything. The energy is about 50 joules, or about 1/2 of the heat that a human body produces in a second.
    - r2_pilot 3y ago
      I wonder if it would kill a flea, or barring that, a bacterium.
  - hollerith 3y ago
    Earth's atmosphere and magnetic field prevents these kinds of rays from reaching the surface of the Earth.
- hollerith 3y ago
  Interesting. I see from your link that this particle had 1/6 of the energy of a lethal dose of x-rays. I'm guessing I would probably survive, but certainly wouldn't volunteer to get hit with such a particle, and I'm guess that if it went through my brain stem or maybe my heart, there's a good chance it would kill me.
klyrs 3y ago
> The Oh-My-God particle had 10^20 (100 quintillion) times the photon energy of visible light, equivalent to a 142-gram (5 oz) baseball travelling at about 28 m/s (100 km/h; 63 mph) For comparison a typical professional baseball pitch is around 90mph. At 63mph I guess it might not break your face, but it would certainly leave a bruise (if it was actually a baseball -- who knows what the actual particle would do to flesh and bone). I know people are pretty derisive about using swimming pools or whatever for measurement, but I think this one is pretty good for bringing incomprehensible numbers into the realm of lay-understanding.
- orangea 3y ago
  Note that such a baseball with the same energy as this particle would still have much more momentum than the particle. So getting hit by the particle wouldn't "leave a bruise".
- rsiqueira 3y ago
  Is this equivalent to a 14 gram bullet (10x less than your example) travelling at 1000 km/h (10x more than your example)? Or a 1,4 gram bullet at 10.000 km/h hitting you?
  - klyrs 3y ago
    I don't think so, no. Kinetic energy grows with the square of velocity, and linearly with mass. So a 14g bullet travelling at 316km/h or a 1.4g bullet travelling at 1000km/h. But for what it's worth, I think most people have more experience catching baseballs than bullets (and I don't know how much bullets typically weigh or how fast they travel).
- Gibbon1 3y ago
  No idea about a particle like this one but, I've read that cosmic rays pass through flesh leaving a microscopic track of destruction[1]. However atomic collisions result in a shower of particles. And very high energy you get multiple showers. A problem if you're trying to shield people in space for a long time. You need enough shielding to stop the secondary showers of particles. [1] Extreme example from memory... meh google, In 1978 Soviet physics student Anatoli Bugorski got zapped by a proton beam which burned a track through his head. Recovered with damage, completed his PhD and is still alive.
HansHamster 3y ago
One thing to keep in mind is that the particle will likely only lose a 'tiny' fraction of its energy in a collision (the article mentions 2900 TeV for an atom of nitrogen) and it might not even cause a 'hard' collision. A collision will probably create a shower of particles which will carry away most of the energy.
dredmorbius 3y ago
The critical factor here is less the energy of the particle than the mechanism of transmission. As others have noted, the total energy equivalent is that of a moderately-fast baseball throw, which, in the case of a baseball is perceptible but generally not harmful. The transmission mechanism for the baseball is the electromagnetic force, where the individual molecules of the baseball are interacting with the individual molecules of your body, and the imposed and reactive forces are roughly equivalent. In the case of the OMG particle, as a proton it would exert a positive charge, and might steal an electron (becoming a hydrogen atom in the process), or interact directly with a nucleus, though likely splitting that. The atoms of your body are principally carbon, hydrogen, oxygen, and nitrogen, atomic numbers 1, 12, 14, and 16, respectively. The result of such an interaction might be isotopes of: H, He, Li, Be, or B, numbers 1--5 inclusive. There would likely be a chain of such interactions depending on the effective cross-section of the incident particle, atoms in your body, and any collision particles, though this is pretty much where my physics knowledge abandons me. Online sources suggest that this is pretty accurate: the particle would pass straight through you: <https://www.technology.org/how-and-why/if-proton-nearly-at-light-speed-hit-your-hand-would-you-feel-anything/ https://www.technology.org/how-and-why/if-proton-nearly-at-l...> Presuming there is a collision within your body, at this point you have a particle stream, interacting with other material through electromagnetic and nuclear (strong and weak) forces. Again, you're dealing with exceedingly high energies, and it seems likely to me that those particles would tend to exit your body and have further interactions with the surrounding region (air and solid matter), which would result in some local ionisation and light heating. The question is the interaction cross-section of the incident particle, atoms within your body, and any collision and decay products. Point being that you don't want to necessarily direct the maximum energy at a target, but the energy that will disrupt or interact with that target in the manner in which you intend. Cosmic rays are striking your body all the time, though at lower energies. The effects tend to be local ionisation and, most critically, damage to genetic material. The latter is the most significant from a biological perspective.
elil17 3y ago
My new best guess is that most of the energy would no be contained in your body but would be ejected out as a bunch of other high energy particles (just not that high energy).

by elil17 3y ago

TooKool4This 3y ago

Wikipedia has it in the comparison. It’s more like getting punched. Really hard. https://en.m.wikipedia.org/wiki/Orders_of_magnitude_(energy) https://en.m.wikipedia.org/wiki/Orders_of_magnitude_(energy)

KyleBerezin 3y ago
Hmm, I think the effect would be more localized, and involve a lot of strange forms of matter. My guess is it would be similar to what happened to Anatoli Bugorski when he stuck his head into a proton beam.
orangea 3y ago
That doesn't mean getting hit by this particle would feel like a punch, since what you feel when you get punched is a transfer of momentum rather than a transfer of energy.
- TooKool4This 3y ago
  Yep but just an easy first approximation since the article didn’t have any numbers on the momentum of the particle. I’m sure if you wanted a really good answer you would need more than momentum and actually need to analyze the products of the collision like another poster suggested. Also wanted to share this table since energy expressed in eV sounds like big numbers but it’s nice to understand that the definition of the eV is small in our usual definition of energy.
petercooper 3y ago
So I'm confused. If some specific relatively small devices (relatively to the size of the Earth) managed to pick up several of these over the years, surely some of these are hitting people? Are people randomly feeling like they got impacted (if not punched, as per a sister comment) out of nowhere? Apologies if this is a ridiculous question; physics was always my weak suit.
- orangea 3y ago
  If you got hit by one of these then you wouldn't feel anything. The energy is about 50 joules, or about 1/2 of the heat that a human body produces in a second.
  - r2_pilot 3y ago
    I wonder if it would kill a flea, or barring that, a bacterium.
- hollerith 3y ago
  Earth's atmosphere and magnetic field prevents these kinds of rays from reaching the surface of the Earth.
hollerith 3y ago
Interesting. I see from your link that this particle had 1/6 of the energy of a lethal dose of x-rays. I'm guessing I would probably survive, but certainly wouldn't volunteer to get hit with such a particle, and I'm guess that if it went through my brain stem or maybe my heart, there's a good chance it would kill me.

klyrs 3y ago

> The Oh-My-God particle had 10^20 (100 quintillion) times the photon energy of visible light, equivalent to a 142-gram (5 oz) baseball travelling at about 28 m/s (100 km/h; 63 mph) For comparison a typical professional baseball pitch is around 90mph. At 63mph I guess it might not break your face, but it would certainly leave a bruise (if it was actually a baseball -- who knows what the actual particle would do to flesh and bone). I know people are pretty derisive about using swimming pools or whatever for measurement, but I think this one is pretty good for bringing incomprehensible numbers into the realm of lay-understanding.

orangea 3y ago
Note that such a baseball with the same energy as this particle would still have much more momentum than the particle. So getting hit by the particle wouldn't "leave a bruise".
rsiqueira 3y ago
Is this equivalent to a 14 gram bullet (10x less than your example) travelling at 1000 km/h (10x more than your example)? Or a 1,4 gram bullet at 10.000 km/h hitting you?
- klyrs 3y ago
  I don't think so, no. Kinetic energy grows with the square of velocity, and linearly with mass. So a 14g bullet travelling at 316km/h or a 1.4g bullet travelling at 1000km/h. But for what it's worth, I think most people have more experience catching baseballs than bullets (and I don't know how much bullets typically weigh or how fast they travel).
Gibbon1 3y ago
No idea about a particle like this one but, I've read that cosmic rays pass through flesh leaving a microscopic track of destruction[1]. However atomic collisions result in a shower of particles. And very high energy you get multiple showers. A problem if you're trying to shield people in space for a long time. You need enough shielding to stop the secondary showers of particles. [1] Extreme example from memory... meh google, In 1978 Soviet physics student Anatoli Bugorski got zapped by a proton beam which burned a track through his head. Recovered with damage, completed his PhD and is still alive.

HansHamster 3y ago

One thing to keep in mind is that the particle will likely only lose a 'tiny' fraction of its energy in a collision (the article mentions 2900 TeV for an atom of nitrogen) and it might not even cause a 'hard' collision. A collision will probably create a shower of particles which will carry away most of the energy.

dredmorbius 3y ago

The critical factor here is less the energy of the particle than the mechanism of transmission. As others have noted, the total energy equivalent is that of a moderately-fast baseball throw, which, in the case of a baseball is perceptible but generally not harmful. The transmission mechanism for the baseball is the electromagnetic force, where the individual molecules of the baseball are interacting with the individual molecules of your body, and the imposed and reactive forces are roughly equivalent. In the case of the OMG particle, as a proton it would exert a positive charge, and might steal an electron (becoming a hydrogen atom in the process), or interact directly with a nucleus, though likely splitting that. The atoms of your body are principally carbon, hydrogen, oxygen, and nitrogen, atomic numbers 1, 12, 14, and 16, respectively. The result of such an interaction might be isotopes of: H, He, Li, Be, or B, numbers 1--5 inclusive. There would likely be a chain of such interactions depending on the effective cross-section of the incident particle, atoms in your body, and any collision particles, though this is pretty much where my physics knowledge abandons me. Online sources suggest that this is pretty accurate: the particle would pass straight through you: <https://www.technology.org/how-and-why/if-proton-nearly-at-light-speed-hit-your-hand-would-you-feel-anything/ https://www.technology.org/how-and-why/if-proton-nearly-at-l...> Presuming there is a collision within your body, at this point you have a particle stream, interacting with other material through electromagnetic and nuclear (strong and weak) forces. Again, you're dealing with exceedingly high energies, and it seems likely to me that those particles would tend to exit your body and have further interactions with the surrounding region (air and solid matter), which would result in some local ionisation and light heating. The question is the interaction cross-section of the incident particle, atoms within your body, and any collision and decay products. Point being that you don't want to necessarily direct the maximum energy at a target, but the energy that will disrupt or interact with that target in the manner in which you intend. Cosmic rays are striking your body all the time, though at lower energies. The effects tend to be local ionisation and, most critically, damage to genetic material. The latter is the most significant from a biological perspective.

elil17 3y ago

My new best guess is that most of the energy would no be contained in your body but would be ejected out as a bunch of other high energy particles (just not that high energy).