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Cake day: June 22nd, 2023

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  • Actually, kinda. Space is not a true vacuum, the particles per cubic meter is just really low, low enough that it’s basically close enough for most stuff humans do in space. But, IIRC, when you travel at relativistic speeds and keep closing in on light speed, these particles are enough that there’s a similar effect to air resistance in terrestrial travel.
    I could be wrong though, it’s hearsay and I’m not even sure where I got this from. I think it might have been SFAA though.

    Edit: found this:

    1. Density of Matter in Space

    It seems to me that with space travel, the speed of a spacecraft would be limited by the matter in space due to friction. Is this true?

    The density of matter in our Galaxy is about 1 particle/cm³ (in the disk, with the halo being less dense). The density of matter in intergalactic space (between galaxies) is about 2 x 10^-31 gm/cm³, mainly hydrogen. At these densities, I don’t think one has to worry about friction.

    Dr. Louis Barbier

    1. Friction in Space

    Does friction exist in deep space?

    Yes, when two surfaces rub together in outer space, there will be friction. Friction is a surface effect and doesn’t depend upon there being air. There is also a force like air resistance from the very sparse gas in space, but it will be very, very small, since space is a very good vacuum.

    Dr. Eric Christian