Video Throughput: Armageddon

Michael Siegel

Michael Siegel is an astronomer living in Pennsylvania. He blogs at his own site, and has written a novel.

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7 Responses

  1. Em Carpenter
    Ignored
    says:

    So what I heard here was that you enjoyed watching this very imaginative movie?
    😉
    Thanks for this. Need to watch it again soon since you cut out all the best parts for the vid!Report

  2. Jaybird
    Ignored
    says:

    Holy crap. This is an hour long.Report

  3. Michael Cain
    Ignored
    says:

    Interesting, as always :^)

    Production nitpick: inconsistent audio levels. Rather than constantly fiddle with my computer’s volume level, or decide between inaudible movie clips vs you “yelling” at me, I finally downloaded the whole thing and played it with VLC and its dynamic range compression on max.

    Where I think you’re wrong: when you describe the Shuttle returning to Earth at 22,000 mph as a problem. Apollo capsules, and the Orion capsule tentatively/optimistically scheduled for launch next month, had/will have final return velocities right at 24,000 mph. To borrow from Heinlein:

    But no matter how he threw them, final velocity at Terra would be close to Terra’s escape speed, near enough eleven kilometers per second as to make no difference. That terrible speed results from gravity well shaped by Terra’s mass, eighty times that of Luna, and made no real difference whether Mike pushed a missile gently over well curb or flipped it briskly. Was not muscle that counted but great depth of that well.

    As I recall, Apollo had to hit the atmosphere at a very precise angle: too shallow and they would skip off, too steep and they would burn up. The description I remember is “like hitting a dime with a rifle at a range of a mile.” The Shuttles might not have been built for that kind of stress, although they did reenter from an orbital speed around 17,000 mph. All sorts of orbital mechanics complications when you’re coming in from far out, of course, but there’s a reason the typical impacter has a terminal velocity around 25,000 mph.Report

    • Michael Siegel in reply to Michael Cain
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      says:

      That’s correct, but the velocities are’t quite the same. I spent some time trying to work this out because it took Apollo 2 days to reach the moon, whereas at 24k, it would take hours. I don’t think that’s relative velocity but I could be wrong.Report

      • Michael Cain in reply to Michael Siegel
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        says:

        24,000 when you start, but steadily slowing as you go away from the earth.

        Simplified numbers for a sanity check. Consider a highly-eccentric elliptical orbit around Earth with a perigee of 500 km and an apogee of 384,400 km. According to this calculator the perigee velocity is 10.7 km/s (~24,000 mph) and the apogee velocity is 0.2 km/s (~450 mph). The period is 245 hours, so the outbound leg is just over five days.Report

    • Oscar Gordon in reply to Michael Cain
      Ignored
      says:

      Correct, you have to re-enter from what is a relatively stable orbit. Orbital speed at 100 km (Karman line) is ~17500 mph. You can go faster than that, but absent rockets for a controlled descent, you won’t go any slower until you start dipping into atmo.Report

  4. rexknobus
    Ignored
    says:

    Very nice video essay. I have come up with a few of those same criticisms myself while watching the silly thing, but I’m no physicist, so I loved getting even more Kepler-ish dope. But I must shamefacedly admit that I get a kick out of this preposterous movie and have watched it many times. There’s no hope for FX and goofy heroics nerds like me.

    But then, I am almost constantly barraged by the preposterous in movies. You know that evil looking medical saw that all the villains pull out in the torture scenes? The handheld one with the heavy motor and the vicious, circular, toothed saw? Yeah, it’s a cast saw. The blade doesn’t spin (think of the mess in the O.R. if that blade was cutting, unshielded, into anything). It just vibrates through plaster. You can put that buzzing blade right on your hand and just get a little tickle.

    And don’t get me started on firearms in movies…

    Anyway, I liked your presentation and look forward to more. Thanks.Report

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