beesKinda fucked up tbh
Hmm, I think this logic kinda fails because if astronauts are “not on earth”, then neither are air travelers.
Astronauts orbiting earth are just couple kilometers higher altitude
jlow (he / him)Let’s make some artificial rule like you need to be not on earth for 48 hours to be not on earth or something …
MintyFreshCan be at rest in your own reference frame without falling to earth?
Can I define my reference frame any way I want? Because if so, yes. And also no
Da Bald EagulFrom your own reference frame, wouldn’t earth be falling to you? Because then this’d apply to everyone, always.
I think better would be to include Earth’s orbit as “on earth”. This makes sense even if we expand our scope of operations to other planets
The Moon is not on Earth.
The moon and earth are “on” a shared center of gravity. It just so happens to be inside to earth, so meh, we win.
We already have a definition for this, the Karman line.
CarbonIceDragonUnless you define “on earth” to be "below the Kármán line. The Earth’s atmosphere is probably to be considered part of the planet, else gas planet like Jupiter get difficult to talk about consistently. Atmospheres don’t have a proper “cutoff”, they just get thinner and thinner until they gradually become insignificant, so some cutoff is going to have to be arbitrarily defined to make the distinction useful.
Karman line could be a good limit sure, but I think the orbit still kinda makes sense to include “on the planet”.
Say for example if the apartheid baby gets his Mars colony thing going, from Earth’s perspective it wouldn’t make much difference if a person is standing on Mars surface or on the orbit - we could say that the person is on Mars.
They would be in Mars orbit, but not planetside. “At Mars” might be a middle ground designator.
Swednecki’d say being in orbit is arguably the least on a planet can be, since an orbit is specifically continuing to miss falling onto the planet.
DaveI mean 30,000 feet is 9km. The Kármán line is 100km. The ISS is at an average altitude of 400km.
It’s a bit like saying people in planes don’t count as flying because then people on trampolines should count.
Are you saying that people jumping ARE on earth? Because I disagree.
They’re clearly not “jumping” they’re pushing the earth away
That’s relatively true
Are there enough trampolines on earth that we could reasonably expect that at any time there is at least one person in the upper part of their jump on a trampoline?
sp3ctr4lAlso people who live in a basement, or cave, or underground complex of some kind, or who are currently caving, … they also aren’t ‘on’ Earth, they’re ‘in the Earth’, … and people currently in submersibles, under the water line, well they’re not on the surface, they’re in or under the ocean or w/e, by this grammatical level of pedantry.
When I jump, I am not in earth.
No, you’re over Earth.
Spent a moment thinking about this and I think there’s an implied definition for what “on earth” means that we intuitively accept but don’t ever really need to state.
If your projected free-fall trajectory both forward and backward in time intersects with the surface of the earth then you are “on earth”.
Standing on the ground? Intersects twice. Thrown rock? Intersects twice. Person in an airplane? Intersects twice. ISS? No intersection. Incoming impact meteor? One intersection.
The ISS was launched from Earth, in pieces but still it's of Earth origin, and will eventually fall back to Earth. It's inside the Earth's atmosphere and experiences drag. It's orbit has to be adjusted and maintained.
Yes, that’s all true, but none of that describes its free-fall trajectory. Drag causes it to deviate from free-fall very slightly, and it definitely wasn’t in free-fall when the pieces were launched from Earth
Space is a priority so we can ignore climate change. Rockets put our many many plane flights worth of pollution, elon musk has done over 30,000 of them. Quite a few ended up just dumping raw pollution and parts into the ocean.
No price is paid but by the environment.
Space is a priority so we can ignore climate change.
I have a teacher that once said that even if we nuked the entire planet and gave 100 years to terraform Mars. Mars would still be less habitable than Earth. Colonization of space in the near future is a pipedream.
Pssh, those are only the humans we know of.
macnielIt’s said, that life here began out there…
gon [he]Holy shit.
I’ve never been alive in a time when every human has been on Earth. That’s crazy to think about…
PeppycitoGet off my lawn.
Oxysis/OxyThis planet ain’t big enough for the two of us.
The loser has to go to space.
Oh no I’ll ‘accidentally’ lose and finally be free from this world.
If you like pedantry, people have definitely flown in vehicles and even jumped.
I like pedantry but want to go the other way. The ISS orbits in the thermosphere, still inside Earth's atmosphere. I say that you haven't really left Earth until you exit the atmosphere.
What’s wrong with the karman line?
So basically, the Karman line is the theoretical highest point that an airplane can fly, or at least it was when it was calculated. If it were recalculated today it would be higher because of technological advancement. The definition used by the agencies that define it as the edge of space set an altitude near the originally calculated line. The functional difference between being above the line and below the line is that the keplar force will keep an object above the line from falling to Earth within 24 hours while drag will slow the object below the line enough for it to fall back to Earth within 24 hours. It's fine as a functional definition but I see no reason that it should be universally applied. In the scope of this discussion why should we consider something that will fall back to Earth in 25 hours not be on Earth but something that will fall back to Earth in 23 hours to be on Earth?
itslilithThat’s highly pedantic, you need to draw the line somewhere. At 120 km you get long-ish sustainable orbits, at 80 km objects decay within a single orbit. The ISS sits at around 420 km, well above that
Btw, the airplane limit calculated by von Kármán was closer to 80 km, the 100 km limit is not based on his calculations.
i mean, even those guys who went to the moon still stayed within a very close proximity to the earth compared to the size of the solar system
only when people travel to mars they will really have left the earth
Something Burger 🍔The Moon is basically Earth territory. You can’t go to Hawaii and claim you left the US.
Captain AggravatedI’M FREAKING 24!!!
I have… and by way longer than I want to admit.
Deathray5Saaame
LoudWaterHombreBeing born after 2000 should be illegal
tetris11thank you
They’re old enough to have finished a master’s degree
That is so crazy don’t say that
As a fellow old person, former millennial, I agree.
I had lived in exactly 2 days in my life time in which every human was on earth.
I want more of these facts but I’m not signing up for Twitter
Well, technically speaking, we all are in space.
We are all passengers on a generational space vessel.
We need a better navigator, though. We keep going around in circles.
The Sun isn’t stationary 😉
but it also goes around in circles, or maybe it’s more of a spiral
The Milky Way isn’t stationary 😉
another circle maybe? does anyone really know?