Where is the line between “on Earth” and not? If you’re orbiting the planet does that still count? Do you have to be below a certain altitude? Certainly flying in an airplane isn’t enough to qualify as having left Earth. Is it leaving the earth’s atmosphere? Is that even something with a precise enough definition?
I guess what I’m saying is we should exile Elon to Mars and then start the timer.
It depends upon the definition of “on”, I suppose.
If jumping or falling count as not being “on” earth, the fact is not true since there is (a) almost no chance with so many people that one person (probably a child) somewhere wasn’t jumping or falling and (b) we can’t definitively prove things one way or the other with regard to (a).
If we do say “OK, human-body-powered times not in contact with earth don’t count” (assuming the human is responsible here for cases where they fall, for simplicity), we would have to move on to vehicles. Driving a vehicle that contacts the ground seems pretty “on earth”. I suppose boats would as well. What about planes, thought? They’re definitely “in the air” when they’re not “on the ground” (I’m sticking with English here since the post is in English; we could open another can of words worms for other languages).
So next we have to say “things flying in the atmosphere don’t count” then we have to either define atmosphere or define an arbitrary line of Xkm above the average surface of earth. In the case of the former, how much atmosphere counts as atmosphere?
I guess we could move on to gravity well after that.
If a person fell into the singularity of a black hole that had particles from our atmosphere, are we back to on earth again? (My vote is “s/he dead and no even if not”, but I think it’s interesting to think about).
For NASA and the U.S. military, for example, space starts at an altitude of 50 miles (around 80 kilometers), according to NOAA. However to the international community, including the Fédération Aéronautique Internationale (FAI), space starts a little higher, at 62 miles (100 km), at the Kármán line
Where is the line between “on Earth” and not? If you’re orbiting the planet does that still count? Do you have to be below a certain altitude? Certainly flying in an airplane isn’t enough to qualify as having left Earth. Is it leaving the earth’s atmosphere? Is that even something with a precise enough definition?
I guess what I’m saying is we should exile Elon to Mars and then start the timer.
It depends upon the definition of “on”, I suppose.
If jumping or falling count as not being “on” earth, the fact is not true since there is (a) almost no chance with so many people that one person (probably a child) somewhere wasn’t jumping or falling and (b) we can’t definitively prove things one way or the other with regard to (a).
If we do say “OK, human-body-powered times not in contact with earth don’t count” (assuming the human is responsible here for cases where they fall, for simplicity), we would have to move on to vehicles. Driving a vehicle that contacts the ground seems pretty “on earth”. I suppose boats would as well. What about planes, thought? They’re definitely “in the air” when they’re not “on the ground” (I’m sticking with English here since the post is in English; we could open another can of
wordsworms for other languages).So next we have to say “things flying in the atmosphere don’t count” then we have to either define atmosphere or define an arbitrary line of Xkm above the average surface of earth. In the case of the former, how much atmosphere counts as atmosphere?
I guess we could move on to gravity well after that.
100km. Atmosphere is a gradient so yes it’s entirely arbitrary.
If a person fell into the singularity of a black hole that had particles from our atmosphere, are we back to on earth again? (My vote is “s/he dead and no even if not”, but I think it’s interesting to think about).