Comment on How can we get to Mars faster

• skillissuer@discuss.tchncs.de ⁨3⁩ ⁨weeks⁩ ago

  i don’t get what you fail to understand, water doesn’t became radioactive or harmful in any other way after irradiation, and irradiation of food is routinely used for extending its shelf life

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  • just_another_person@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

    The basis for what you’re saying is that water is some kind of magic shield the reflects radiation, which is not a thing.

    At best, if you’re talking about lining the hull of a spacecraft and expecting that to work, that’s not a thing either because of the water is taking on any extra mass of any kind, it would obviously expand. Water in its purest form would have to take on mass to “absorb” radiation, expanding a hull and destroying it over time. If you left room in there for expansion, you’d die on exit or reentry of atmosphere without freezing it.

    The only way you can reflect radiation without absorbing something is by denying it entry. Water doesn’t do that.

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    • skillissuer@discuss.tchncs.de ⁨3⁩ ⁨weeks⁩ ago

      water does not expand upon irradiation, what the fuck are you talking about. you can’t reflect high energy protons (what would be important in radiation in interplanetary travel) you can only either absorb them or let them pass, there’s no third option, same for anything above uv and electrons

      to a first approximation (rather good one at that) (for gammas) absorption is proportional to how much mass per area unit is used as a barrier. 1 g/cm^2 of water is just as good barrier as 1 g/cm^2 of lead or steel. this means that you can absolutely use completely normal, regular potable water as a radiation shield

      Water in its purest form would have to take on mass to “absorb” radiation, expanding a hull and destroying it over time.

      i’m not even sure what it’s supposed to mean, unless your understanding of ionizing radiation is uncut nonsense

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      • just_another_person@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

        Okay, so where do the neutrons go in your head? Gotta go somewhere.

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