r/theydidthemath 2d ago

[Request] Okay lets try this one

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u/chessgremlin 2d ago

No. The characteristic length for an atom is an angstrom ~10^-10 meters. A toothpick has a thickness of roughly a millimeter, or 10^-3 meters. The earth, at the equator, is roughly 10^7 meters "thick / wide". So a toothpick is around 10^7 times thicker than an atom while the earth is around 10^10 times thicker than a toothpick.

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u/TheJWeed 2d ago

Alright, then what size object should we be looking for that does work for the meme?

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u/1337k9 2d ago edited 2d ago

The atom in that pic has 3 reds, 4 blues and 3 electrons (assuming nothing's hidden behind the nucleus). It could be Lithium with a mass of 6.942 g/mol . A single atom of Lithium has a mass of 6.942 g divided by 6.02214076 × 1023 . Earth has a mass of 5.972 x 1027 grams. To calculate how much bigger the Earth is, use the formula

(5.972g x 1027 ) / (6.942g x 10-23 )

=5.972g / 6.942g x 1050

=5.972 / 6.942 x 1050

The Earth has 5.972 / 6.942 x 1050 times more mass than the atom. Something logarithmically between the two would have a mass of the root of this number. That is

2V[5.972/6.942] x 2V[1050 ]

=2V[5.972/6.942] x 1025

times the mass of the atom. If we're not just interested in ratios and want to know the real world mass, that's

6.941765353712grams / 6.02214076 × 10-23 x 2V[5.972/6.942] x 1025

=6.941765353712grams / 6.02214076 x 2V[5.972/6.942] x 102

≈1.069grams x 100

So 106.9 grams is the logarithmic middle between that Lithium atom and the Earth. An orange weighs about this much.

EDIT: Reddit's formatting

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u/MovinOnUp2TheMoon 1d ago

There’s the Math They Did.

Thanks!