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How could SI units be derived from scratch without the use of modern technology? (lemmy.sdf.org)

submitted 1 year ago by [email protected] to c/[email protected]

45 comments fedilink hide all child comments

Think "you wake up in the woods naked," Dr. Stone-style tech reset. How could humans acquire a 1-gram weight, a centimeter ruler, an HH:MM:SS timekeeping device, etc. starting with natural resources?

My best guess was something involving calibrating a mercury thermometer (after spending years developing glassblowing and finding mercury, lol) using boiling water at sea level to mark 100 ° C and then maybe Fahrenheit's dumb ice ammonium chloride brine to mark -17.7778 ° C, then figuring out how far apart they should be in millimeters on the thermometer (er, somehow). I can already think of several confounding variables with that though, most notably atmospheric pressure.

I feel like the most important thing to get would be a length measurement since you can then get a 1 gram mass from a cubic centimeter of distilled water.

That's as far as I got with this thought experiment before deciding to ask the internet. I actually asked on Reddit a while back but never got any responses.

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[–] [email protected] 2 points 1 year ago (1 children)

oh i know the answer. Since a mars day is about 15 minutes longer and out rover there are solar powered it was important that the human operators of them knew what time it was on mars. Nasa's answer, make a watch that runs about 2% slower. that git the mars watch an extra 15 minutes and so it syncs to the martian sun.

[–] [email protected] 2 points 1 year ago

Figured there would be an answer like this, thanks!