Cheating cheating cheating! He only named the number, I want him to chant the digits. And no doubling up, I demand Avogadro’s number of sequential readings. Out loud, with his mouth, real time.

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No idea what software he used to get the overlay effect (but pretty sure he didn’t do it one mole times, sequentially). What’s interesting though is that the most stable part seems to be the one sibilant (S-sound) in it, which remains discernible all through when everything else has been washed out already.

Which brings me to the question, do you guys say ‘Avogadro’s number’ with a voiced [z] (as in zenith) or an unvoiced [s] one (as in sand)? Shouldn’t it be [z] in this position?

Recursiveness cubed

Might as well include the link to the online version of that “What If…?”
https://what-if.xkcd.com/4/

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I’m sure he wanted to, but the exact value is unknown. Although it’s defined as the number of 12C in in 12 grams, it’s not possible to measure the mass of a single 12C to 24 or more decimal places (the ratio is not a rational number anyway), and worse, the mass of a gram isn’t (and can’t be) known that precisely, since it is still defined in terms of a literal, physical 1kg reference weight, which is prone to change slightly over time.

However, in exciting November election news, this is probably about to change, as the CIPM is expected to vote to redefine the kilogram and the mole, along with many other things. The kilogram will be defined by assigning an exact value to Planck’s constant, and NA will be defined to be 602,214,076,000,000,000,000,000 (meaning a mole of 12C no longer weighs exactly 12g).

I am sure this guy will want to rush out an improved video right after that November 16th vote, unless there is some kind of upset and the kilogram ends up being redefined as “Heil Hitler”, which feels grimly inevitable

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It’s Avogadro’s constant (because it has units).

No it doesn’t. Mass per mass = number of atoms.

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Yeah, it’s a dimensionless number

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I get what you’re saying. The chance that Avogadro’s Number is an integer seems infinitly small. It would require a precise definition of a gram, a way to exaclty weigh a single atom of C12 with respect to said definition of a gram, and a miracle if the weight of that atom of C12 is an integer factor of 12g.

However, the error of rounding Avogadro’s Number to the closest integer will probably be a lot smaller than if you mistakenly switch 12g for a Kg…

But if you say “Avogadro’s Number” three times in a mirror does it appear?

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Oh yeah.

I’ve rewritten history to render your post baffling.

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Didn’t they do that already? Or is it perpetually going to be one of those things that’s going to happen real soon now, but not quite yet?

I’m not a rock-star international metrologist (I wish!), so I don’t know how CIPM politics work, but Wikipedia says their meeting is scheduled for November 16th and they are “expected” to vote for the radical new plan, which would come into effect in 2019. I take that to mean that the vote is a formality, and the new scheme already embodies the outcomes of whatever bitchy cat-fights it took to get to this point.

The new definitions won’t affect most people, except that the new definition of the volt will of course mean that the voltage of household power outlets will increase eight thousandfold overnight, and weight will now be measured in millibar-fathom-square fortnights.

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