• Brainsploosh@lemmy.world
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    1 year ago

    Oh, I apologise, I suffered some curse of knowledge there, the answer is time.

    A blast is a release of energy over a short time, the whole point of building weapons is to store and handle energy in safe amounts over time.

    Global electric energy consumption is about 200 PJ a day, approximately the same as the Tsar Bomba, but there’s no risk for a huge explosion neither when you incinerate trash or turn off the AC.

    Because time.

    Although we could explode a nuke and propel things ballistically, it turns out it’s a lot easier to use rockets. A rocket, although carrying frightening amounts of fuel and exploding spectacularly when it fires wrong, has several safeguards to not expend all that fuel at once. And also gives the opportunity to correct course along the way.

    Now imagine that the same amount of energy has been expended many many many times over the course of the space era, and almost any mass in orbit has serious potential for damage.

    For example, the MIR was 130 tons, orbiting at about 7,8 km/s, for a kinetic energy of 4 TJ, and another 235 GJ of potential energy. Totalling about a tenth of Little Boy that levelled Hiroshima.

    Edit: Specifying and correcting the global energy consumption.

    • Pennomi@lemmy.world
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      1 year ago

      Right, and tungsten rods are dangerous because they don’t slow down and burn up in the atmosphere like most spacecraft do (like you said, spreading out that energy over time and space). As long as you can deorbit them accurately, they are devastating since they convert the entire orbital potential energy into surface kinetic energy all at once. (Oddly, orbital potential energy and surface kinetic energy are the same thing, just from different points of reference.)

      • Brainsploosh@lemmy.world
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        1 year ago

        Agreed. On all points.

        Moreover, the Tungsten rods are quite dense and thus small, and thus very hard to spot on radar or hit with countermeasures.

        • Tlaloc_Temporal@lemmy.ca
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          1 year ago

          I’m not sure countermeasures would even work. Even if you could blast it with a half dozen CWIS for the entire duration it’s in the atmosphere, hitting every shot, you might change the impact zone by a few hundred meters. A high-angle trajectory would be completely unaffected.

    • 🦄🦄🦄@feddit.de
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      1 year ago

      Wait this can’t be right or I am missing something. Are you saying that the Tsar Bomba released 10 PetaJoule of energy more than our current world uses in a year?

      • TAYRN@lemmy.world
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        1 year ago

        It’s… definitely not right. Most estimates I found from a quick Google search put global energy consumption at a bit under 600,000 PJ per year, so even if they meant to say daily energy consumption or something they’d still be off by an order of magnitude.

        The closest I can get to the number they gave is that global daily electricity consumption is a little over 200 PJ, so right on par with estimates for the Tsar Bomba.

    • tryptaminev 🇵🇸 🇺🇦 🇪🇺@feddit.de
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      1 year ago

      Still you need that much energy. And it all needs to be on that rocket. So if anything goes wrong with that rocket, it will burn and release the energy of a nuclear explosion. It will be less devastating than a nuke, because it is burning fuel as opposed to a huge shockwave and temperature, but still it would insanely dangerous.

      And i’ve yet to come across a space program that didn’t include catastrophic failure rocket launches.

      • Tlaloc_Temporal@lemmy.ca
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        1 year ago

        We’ve seen this already. Starship should be capable of at least 100t to orbit, which is about 40TJ of energy on orbit. The Little Boy was 63TJ, so accounting for losses, Starship flight test 1 was exactly what that would look like.

        Do note that much of the energy was lost because most of the fuel didn’t burn, it just evaporated. The Beirut fertilizer explosion was 1/30th the energy, but all released at once.