4 ms·
That's great, but one problem: molecules don't stay molecules over two thousand years. Certainly not oxygen, which is extremely chemically active. N2 somewhat l
by hugh3 15y ago
That's great, but one problem: molecules don't stay molecules over two thousand years. Certainly not oxygen, which is extremely chemically active. N2 somewhat less so (but http://en.wikipedia.org/wiki/Nitrogen_cycle http://en.wikipedia.org/wiki/Nitrogen_cycle), but the chances of any particular nitrogen molecule retaining its identity over two thousand years is incredibly low.
Redo this calculation with atoms, and I might believe you. But it'll need to be a bit more complicated, since I don't think the amount of oxygen and nitrogen getting sequestered in the ocean or the soil is actually "trivial" as stated.
- deleted 15y ago[deleted]
- hunterp 15y agoI think this is a pointless calculation. Why burn cpu cycles on such an old, meaningless question? Wouldn't you rather spend your brainpower helping other people?
- hugh3 15y agoHey, it's better than burning 'em generating bitcoins.
- kailashbadu 15y agoThe problem domain may seem a little wacky but the calculation itself is interesting and could be applied to some other 'meaningful' problems. P.S. - Reminded me of one of those questions they ask at McKinsey when recruiting new analysts. E.g. How many golf balls are in the United States?
- phaedon 15y agoThe setting just motivates the demonstration of a method, which finds use in lots of places. Education is valuable.
- teyc 15y agoCO2 also gets sequestered in plant material. Further reducing the chance.
- anxrn 15y agoAs long as there is some component of air that stays the same: both in identity and proportion, the calculation should hold. Is there such a component? Simplifying assumptions, even those seemingly false, are common in fun math problems. The point is just that, the math. I'm sure the traveling salesman had issues to think about other than the classic math of the problem. Just for my information, any references to strengthen your last statement?
- hugh3 15y agoAs long as there is some component of air that stays the same: both in identity and proportion, the calculation should hold. Is there such a component? Atoms, as long as the amount being sequestered in the water or the soil isn't significant. Oxygen is probably a write-off, since there's far more oxygen atoms in the oceans than in the atmosphere, and since O_2 to H_2O is part of animal respiration. Nitrogen, perhaps, might be more constant, but honestly I just don't know enough about the nitrogen cycle to have a good idea. Ah, but the third most common component of the air is argon, which is deliciously chemically inactive. You could at least compute the probability that you're breathing in some of Caesar's argon. Simplifying assumptions, even those seemingly false, are common in fun math problems. The point is just that, the math. I'm sure the traveling salesman had issues to think about other than the classic math of the problem. Of course. And the other thing that's common in fun math problems is that as soon as you're done someone's gonna say "That's great, but..." and point out something you've ignored. It's all part of the game, and I'm just playing along, not being critical.
- joejohnson 15y agoI think if quantum effects are taken into account, one can show there is almost zero probability that the atoms are the same.
- hugh3 15y agoI'm a physicist. Care to clarify exactly what you mean there?