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Watching it live was more impressive than videos, and the BOOM was really shaking. (I actually live in Chelyabinsk)

dredmorbius 5y ago
I prefer living in my future at a distance ;-) That must have been absolutely amazing. Did you see the initial airburst itself? What were your thoughts / how would you describe your reaction as the event unfolded?
- Andrew_nenakhov 5y ago
  I saw part of the burst and to me it was immediately clear what it was. Also, the timing of the boom arrival helped determine the distance with good precision. Thoughts, 'WOW', 'COOL', 'Did somebody film that??', and, of course, the rest of the workday was not very productive. It was nice to see that so much footage made. One thing footage doesn't show is, however, the heat: the radiation was intense and open parts of the skin did feel hot, like , REALLLY BURNING HOT. Had it lasted longer, there would be burns on everybody.
  - dredmorbius 5y ago
    I've seen estimates of the Chelyabinsk energy yield at about 500 kT TNT equivalent. How that was distributed as light, shock wave, and thermal energy (latter coupled with light) has been something I'd wondered at, and your comment on the heat is interesting. I'd think that a larger impactor or one that survived further into Earth's atmosphere (and closer to the surface) might have changed that experience markedly. You're informing my own advice-to-self as to how to respond should I see a very large airburst at some point. "Stay away from glass" was already part of that, as well as "expect the shockwave after about 90 seconds". I think I'll add "avoid direct thermal exposure if it looks to be large" to the list. If you've not already seen the Sandia Labs modelling based on the 1908 Tunguska event, the shockwave dynamics suggest to me why and how the multiple shockwave arrivals at a given point on the ground occur: https://newsreleases.sandia.gov/releases/2007/asteroid.html https://newsreleases.sandia.gov/releases/2007/asteroid.html Particularly this simulation: http://www.sandia.gov/videos2007/2007-6514Pfire.hv1.1.mpg http://www.sandia.gov/videos2007/2007-6514Pfire.hv1.1.mpg
    - HPsquared 5y ago
      "Resist the urge to stare at it through the window"
      - jacquesm 5y ago
        The one reason Halifax has such a large amount of expertise on eye surgery was people not resisting that urge.
        dredmorbius 5y ago
        From 1917?
        LargoLasskhyfv 5y ago
        That was 191x. And still translates to experience/quality/clustering of eye surgery there? I'm unaware of something like that in locations which suffered from large explosions around a similar timeframe.
        dredmorbius 5y ago
        There's apparently some literature on the topic: https://www.researchgate.net/publication/5633081_The_Halifax_Explosion_of_1917_The_oculist_experience https://www.researchgate.net/publication/5633081_The_Halifax... https://scholar.google.com/scholar?q=eye%20surgery%20halifax%20explosion&btnG=Search&as_sdt=800000000001&as_sdtp=on https://scholar.google.com/scholar?q=eye%20surgery%20halifax...
      - dredmorbius 5y ago
        "Do not look into laser with remaining eye." "Do not gaze upon meteorite armageddon through window with remaining face."
    - sbierwagen 5y ago
      Nukemap has settings for airburst height (under "advanced options"): https://nuclearsecrecy.com/nukemap/ https://nuclearsecrecy.com/nukemap/ For a 10mt explosion at 20km height it shows a third degree burn radius of 27km. Chelyabinsk was ~0.5kt at 29km. Larger objects are expected to penetrate further into the atmosphere before exploding: https://en.wikipedia.org/wiki/Meteor_air_burst https://en.wikipedia.org/wiki/Meteor_air_burst I'm not sure how much time you'd have to evaluate size or distance, videos of Chelyabinsk show it pretty bright just a second or two after becoming visible. Length of infrared exposure determines severity of burn, so reacting early is helpful.

I prefer living in my future at a distance ;-) That must have been absolutely amazing. Did you see the initial airburst itself? What were your thoughts / how would you describe your reaction as the event unfolded?

Andrew_nenakhov 5y ago
I saw part of the burst and to me it was immediately clear what it was. Also, the timing of the boom arrival helped determine the distance with good precision. Thoughts, 'WOW', 'COOL', 'Did somebody film that??', and, of course, the rest of the workday was not very productive. It was nice to see that so much footage made. One thing footage doesn't show is, however, the heat: the radiation was intense and open parts of the skin did feel hot, like , REALLLY BURNING HOT. Had it lasted longer, there would be burns on everybody.
- dredmorbius 5y ago
  I've seen estimates of the Chelyabinsk energy yield at about 500 kT TNT equivalent. How that was distributed as light, shock wave, and thermal energy (latter coupled with light) has been something I'd wondered at, and your comment on the heat is interesting. I'd think that a larger impactor or one that survived further into Earth's atmosphere (and closer to the surface) might have changed that experience markedly. You're informing my own advice-to-self as to how to respond should I see a very large airburst at some point. "Stay away from glass" was already part of that, as well as "expect the shockwave after about 90 seconds". I think I'll add "avoid direct thermal exposure if it looks to be large" to the list. If you've not already seen the Sandia Labs modelling based on the 1908 Tunguska event, the shockwave dynamics suggest to me why and how the multiple shockwave arrivals at a given point on the ground occur: https://newsreleases.sandia.gov/releases/2007/asteroid.html https://newsreleases.sandia.gov/releases/2007/asteroid.html Particularly this simulation: http://www.sandia.gov/videos2007/2007-6514Pfire.hv1.1.mpg http://www.sandia.gov/videos2007/2007-6514Pfire.hv1.1.mpg
  - HPsquared 5y ago
    "Resist the urge to stare at it through the window"
    - jacquesm 5y ago
      The one reason Halifax has such a large amount of expertise on eye surgery was people not resisting that urge.
      - dredmorbius 5y ago
        From 1917?
      - LargoLasskhyfv 5y ago
        That was 191x. And still translates to experience/quality/clustering of eye surgery there? I'm unaware of something like that in locations which suffered from large explosions around a similar timeframe.
        dredmorbius 5y ago
        There's apparently some literature on the topic: https://www.researchgate.net/publication/5633081_The_Halifax_Explosion_of_1917_The_oculist_experience https://www.researchgate.net/publication/5633081_The_Halifax... https://scholar.google.com/scholar?q=eye%20surgery%20halifax%20explosion&btnG=Search&as_sdt=800000000001&as_sdtp=on https://scholar.google.com/scholar?q=eye%20surgery%20halifax...
    - dredmorbius 5y ago
      "Do not look into laser with remaining eye." "Do not gaze upon meteorite armageddon through window with remaining face."
  - sbierwagen 5y ago
    Nukemap has settings for airburst height (under "advanced options"): https://nuclearsecrecy.com/nukemap/ https://nuclearsecrecy.com/nukemap/ For a 10mt explosion at 20km height it shows a third degree burn radius of 27km. Chelyabinsk was ~0.5kt at 29km. Larger objects are expected to penetrate further into the atmosphere before exploding: https://en.wikipedia.org/wiki/Meteor_air_burst https://en.wikipedia.org/wiki/Meteor_air_burst I'm not sure how much time you'd have to evaluate size or distance, videos of Chelyabinsk show it pretty bright just a second or two after becoming visible. Length of infrared exposure determines severity of burn, so reacting early is helpful.