It's usual to see the altitude in feet or in km, but not in miles indeed. It's also funny, in a wicked sort of way, because it shows how thin the main part of the atmosphere is, even far from the poles.
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Yes. And rockets don't take many minutes going up there.
Vaelith
Keeper of the Watch
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I've read before that if Earth was downsized to be as small as a billiard ball, it would be the smoothest billiard ball you'd ever touch, and your fingertips would barely even get wet, despite how big we perceive mountains and oceans to be. The downside of being so tiny compared to everything is that we lack perspective on everything that's around us.
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I suppose height is tricky for us because we're used to moving parallel to the surface (preferably on it 
). Going up and down is a lot more complicated for several reasons.
). Going up and down is a lot more complicated for several reasons.
The diameter of earth is a bit more than 12600 km. The height of the highest mountain at 8.9km above sea level, is therefore about 0.07% of the diameter of earth.
Billiard balls (apparently) have different sizes, but let's assume 60mm in diameter on average, or 0,06m. 0.07% of that is 4.23*10^5 m or about 42 micrometer.
So an accurate copy of earth at the size of a billiard ball would have Mount Everest being 42 micrometers high.
The circumference of earth is about 40000 km. The Himalayas (which are on average Very Large© mountain) are about 2400 km long. But it is curved so let's say 2000 km. That's about 5% of the circumference of Earth.
5 % of 60 mm x π is a bit more than 9 mm. So let's say it has a bump that's 0.03-0.04 mm that's 9mm long. No idea if that's the smoothest billiard ball ever, but it surely would be very smooth.
And the Mariana Trench is about 11 km deep, so not much deeper than the Everest is high. Let's say 0.05 mm deep. Would even an average size drop of water fit in the entire oceans?
This all assumes my quick math wasn't completely wrong... I did it while waiting for a patient who seems to have forgotten our appointment...
Billiard balls (apparently) have different sizes, but let's assume 60mm in diameter on average, or 0,06m. 0.07% of that is 4.23*10^5 m or about 42 micrometer.
So an accurate copy of earth at the size of a billiard ball would have Mount Everest being 42 micrometers high.
The circumference of earth is about 40000 km. The Himalayas (which are on average Very Large© mountain) are about 2400 km long. But it is curved so let's say 2000 km. That's about 5% of the circumference of Earth.
5 % of 60 mm x π is a bit more than 9 mm. So let's say it has a bump that's 0.03-0.04 mm that's 9mm long. No idea if that's the smoothest billiard ball ever, but it surely would be very smooth.
And the Mariana Trench is about 11 km deep, so not much deeper than the Everest is high. Let's say 0.05 mm deep. Would even an average size drop of water fit in the entire oceans?
This all assumes my quick math wasn't completely wrong... I did it while waiting for a patient who seems to have forgotten our appointment...
I didn't check but it's not shocking (the maths, not the forgetful patient). Except it's cheating a little to compare the mountain's height to the diameter and not the radius.
That gives a good perspective. And we humans wouldn't even be as big as specks of dust, I imagine.
PS: If you were French, you could have made the association with billiard because of the idiom 'passer sur le billard' (lie on the billiard table), which means to have an operation - maybe what your patient was trying to avoid. But I see that's one the British haven't stolen from us.
That gives a good perspective. And we humans wouldn't even be as big as specks of dust, I imagine.
PS: If you were French, you could have made the association with billiard because of the idiom 'passer sur le billard' (lie on the billiard table), which means to have an operation - maybe what your patient was trying to avoid. But I see that's one the British haven't stolen from us.
Good gift for dog owners this Xmas.
From Clifford Stoll: The Cuckoo's Egg (which really is a book about hacking back in the eighties, hereby very much recommended": "Why is the sky blue?"
pibbuR who can't think of anything to say
PS.
"Why is the sky blue?" was a question asked at the end of his physics oral exam - the questoner hadn't said anything during the seance until the very end. Stoll gave an answer (which I don't remember) to witch said questioner repeatedly asked "Could you be more specific?", eventually leading him to the very (and very detailed) basis of quantum mechanics.
DS.
I loved that book, which is a true story and gives an interesting account of how relax things were at the time.
Yes, that simple question about the blue sky (and its other possible colours) is a surprisingly bottomless pit. We saw a part of the answer at university but it requires enough knowledge in several branches of physics. It's perfect for an astrophysicist, I guess.
tl;dr; This one does require that you have some knowledge of statistical hypothesis testing. But if you you, I promise it's funny.
pibbuR who aknowledges that H0 is also the symbol of the Higgs boson and that H^0 is one.
pibbuR who aknowledges that H0 is also the symbol of the Higgs boson and that H^0 is one.
I'm not entirely sure. Did he read about some statistical result that concluded there was a relationship between its variables?
The joke is about treating the null hypothesis like a hypothesis of it's own, like the Riemann hypothesis in mathematics, or the Gaia Impact hypothesis in solar system physics (creation of the moon from a collision between earth and a mars sized planet).
892: Null Hypothesis - explain xkcd
Explain xkcd is a wiki dedicated to explaining the webcomic xkcd. Go figure.
www.explainxkcd.com
"... a null hypothesis depends on context. There is no one "the null hypothesis." It refers to a method of statistical analysis (and falsifiability, not a specific hypothesis). Given that, Megan's response would probably be to facepalm."
pibbuR who really appreciates jokes like that
Even more devious than I thought.
pibbuR who for the record prefers dark things
pibbuR who is reminded of Siri, Alexa, Cortana and the ever annoying Google assistant. And Bixby.
Since I know some of you guys like math riddles...
