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I read a book a few days ago talking about how precise are quantum experiments compared to the experiments of other theories, and one sentence got stuck in my head: making an example, because we make experiments with atoms, and they have different probabilities and randomness, and we work with millions and billions of them, we have very precise results (the sentence was not exactly like that). So the thing is that I still don't get why because we don't know everything about ONE particle is better for a experiment with MILLIONS?

Thanks. Sorry if I didn't expressed good enough.

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    $\begingroup$ Is there a way you can get the exact quote? $\endgroup$ – Aaron Stevens Aug 29 '18 at 23:23
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    $\begingroup$ It kind of hinges on the assumption that things of the same type have the same properties (i.e. all electrons are intrinsically indistinguishable) and so if we show something is true for one of those things, and then for a LOT of them, by a statistical argument that makes us very confident in the results. $\endgroup$ – N. Steinle Aug 29 '18 at 23:35
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    $\begingroup$ fanpop.com/clubs/animal-humor/images/8906829/title/… $\endgroup$ – user93146 Aug 29 '18 at 23:45
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If you toss a million coins (or one coin a million times), you can't predict the result for any particular coin, but the odds are around 98% that the total number of heads is between 499,000 and 501,000. That is, the range of deviation from the number of heads being exactly half of the total number of coins is 1/1000 of the total number of coins. In general, the deviation with that probability is equal to the square root of the total number of coins, so if we tossed a trillion coins, the deviation would be a million, which is one part in a million.

A trillion sounds like a lot, but when it comes to atoms, it's still a tiny amount. A trillion trillion molecules of water is just under 30 mL. So when we do experiments with macroscopic quantities of matter, the effects of the randomness & probabilities that affect individual atoms & subatomic particles get averaged out.

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