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Joined 3 years ago
Cake day: June 25th, 2023
  • SkybreakerEngineer@lemmy.worldtoNo Stupid Questions@lemmy.world•If a Space Elevator became a reality, wouldn't the cable act as a kind of wick for all of the unfiltered radiation from outside our atmosphere?English
    51·
    19 days ago

    Any time you talk radiation, you need to be specific about what kind of particles, how much energy they have, and how much of it there is.

    Most of the stuff in orbit is charged particles (electrons and small atoms) and low energy photons. Those get stopped by relatively thin layers of shielding, but if you’re not careful you’ll get cooked from raw heat.

    Ionizing radiation like neutrons or x- and gamma-range photons can radioactivate materials, and take more shielding – think feet of water or a couple inches of lead. Nuclear reactors have that, but spaceships don’t. Fortunately unless you bring a reactor with you they’re rare enough that it’s not really necessary.

    Substances become radioactive when they get hit by some kind of ionizing radiation and change into an isotope that itself emits radiation. Conducting radiation like a wick isn’t really a thing.

  • SkybreakerEngineer@lemmy.worldtoTechnology@lemmy.world•Who cares about the Baltic Jammer? – Terrestrial Navigation in the Baltic Sea Region (39C3)English
    10·
    1 month ago

    Civilian-use GPS signals are unencrypted specifically because they want to be as open as possible. It was originally a military only system, that was only opened up in 2000 after a civilian airliner blundered into Russian airspace and got shot down.

    Military-only signals are encrypted. There are also newer civilian-only signals with checksums and on alternative frequencies but there aren’t enough of the new sats up yet to live on it fully. Check whether your phone supports dual-band GPS, or specifically the L5 signal. There are even apps you can download that will display the full output of your GPS chip, including every satellite in view.