• hemko@lemmy.dbzer0.com
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      3 days ago

      Yeah that’s called Kármán line, but it’s just arbitrary line. ISS is still orbiting within Earth’s thermosphere

      • ilinamorato@lemmy.world
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        2 days ago

        The Karman Line’s lowest theoretical point is still substantially higher up than commercial airplanes and its highest is substantially lower than the ISS. Most nations agree on it as the boundary for the purposes of law and regulation. Commercial airplanes fly about half as high as the line, while spacecraft orbit at four times its altitude or more.

        It may be scientifically arbitrary, but it’s got a lot going for it as a rough approximation.

      • chunes@lemmy.world
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        2 days ago

        My favorite fact is that earth’s atmosphere extends 95,000 miles / 150,000 km beyond the moon.

        • hemko@lemmy.dbzer0.com
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          2 days ago

          I couldn’t find any source for that, but exosphere is considered to extend to 10,000km or 190,000km, from which the latter is about halfway to the moon.

          Anyways those numbers are pretty damn tiny even on a small solar system scale

          Anyways, even if you look from very close, from our own moon to the earth, anything on the low earth orbit is so extremely close to the planet. Just look at some of the famous earthrise photos, and think of something orbiting ~8% of the radius distance

      • TheTechnician27@lemmy.world
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        3 days ago

        Extremely pedantically, sure. But under that level of pedantry, the whole metric falls apart anyway because there’s surely never or rarely been a point in recorded human history where someone hasn’t jumped/fallen/not been physically touching the ground themselves (let alone this having been measurable). What about “touching”; your feet are just repelling the ground via electromagnetism.

        It’s really obvious what the metric is, and trying to pedant-proof it isn’t worth bloating it into a mouthful. We can just recognize what it obviously means, say “oh, neat”, and move on with our day.

        • Tiresia@slrpnk.net
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          2 days ago

          The last time everybody was touching a solid object connected to the Earth by touching other solid objects is probably around 15,000 years ago, when humans crossed over into the Americas. Before then, it would probably occur regularly that nearly all humans are asleep and the handful that are awake happen to all be touching the ground.

        • Rolder@reddthat.com
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          2 days ago

          Does it really count as being “on earth” if you’re standing on a floor instead of having your feet directly touch the dirt?

      • davidgro@lemmy.world
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        3 days ago

        I guess you could count the atmosphere as part of earth, then things over 100km are in little enough of the atmosphere that it’s not really ‘touching’ it the same way. (For example not generating significant lift)