Alt accounts that are also me:

  • 559 Posts
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Joined 3 years ago
Cake day: June 10th, 2023
  • threelonmusketeers@sh.itjust.workstoAsk Science@lemmy.world•Why are space shuttles always rockets, and take off straight upward?English
    7·
    1 day ago

    Pretty good summary. I’ll add a couple corrections:

    This usually involves liquid oxygen. That’s heavy and under pressure

    The critical point of oxygen is below room temperature, meaning it is not possible to keep oxygen liquid using pressure alone. For rockets, liquid oxygen is typically loaded within hours or minutes prior to launch, before it has a chance to warm up and boil off.

    winning solution that could escape earth’s gravity well was the Falcon 9. A multi-stage rocket with different fuels for different stages

    Falcon 9 is a two-stage rocket, but it uses the same propellants (kerosene and liquid oxygen) on both stages.

    Also, I’m not sure if I would call the Falcon 9 the winning solution, just the “winningest” solution so far. SpaceX’s Starship, Stoke Space’s Nova, and any of the upcoming Falcon 9 clones have the potential to improve on the Falcon 9 design or solve the challenge of reusability in slightly different ways.

  • threelonmusketeers@sh.itjust.workstoCooking @lemmy.world•GyudonEnglish
    1·
    9 days ago

    Reminds me of a passage from Uncle Tungsten | Memories of a Chemical Boyhood by Oliver Sacks

    Somewhat graphic description warning

    Chapter Eight: Stinks and Bangs

    Another experiment, suggested by David, involved pouring concentrated, oily sulphuric acid on a little sugar, which instantly turned black, heated, steamed, and expanded, forming a monstrous pillar of carbon rising high above the rim of the beaker. ‘Beware,’ David said, as I gazed at this transformation. ‘You’ll be turned into a pillar of carbon if you get the acid on yourself.’ And then he told me horror stories, probably invented, of vitriol throwings in East London, and patients he had seen coming into the hospital with their entire faces all but burned off. (I was not quite sure whether to believe him, for when I was younger he had told me that if I looked at the Kohanim as they were blessing us in the shul – their heads were covered with a large shawl, a tallis, as they prayed, for they were irradiated, at this moment, by the blinding light of God – my eyes would melt in their sockets and run down my cheeks like fried eggs.)

    Footnote 9: I read John Hersey’s Hiroshima a few years later, and I was struck by this passage:

    When he had penetrated the bushes, he saw there were about twenty men, and they were all in exactly the same nightmarish state: their faces were wholly burned, their eyesockets were hollow, the fluid from their melted eyes had run down their cheeks. (They must have had their faces upturned when the bomb went off…)

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