this post was submitted on 24 Sep 2023
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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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[–] janus2@lemmy.sdf.org 3 points 1 year ago (1 children)

Ah, so at sea level a bucket of ice water would make a decent approximation of 0 ° C, then, I suppose.

Didn't know really tiny ice particles spontaneously fused, this is neat to know

[–] A_A@lemmy.world 2 points 1 year ago* (last edited 1 year ago)

Yes a bucket of a mixture of small ice pellets, say a few millimeter size, plus water, (this bucket being enveloped with some insulation) would be a great zero degrees Celsius reference point.

if you want something more precise you can read this :
https://en.m.wikipedia.org/wiki/Celsius

... "the actual melting point of ice is very slightly (less than a thousandth of a degree) below 0 °C." ...

isotopic distribution of heavy and light elements in water also has a very slight effect on melting point. So, rainwater and water distilled from ocean will not melt at the (exact) same temperature.

See : Vienna Standard Mean Ocean Water https://en.m.wikipedia.org/wiki/Vienna_Standard_Mean_Ocean_Water

Now, about small particle fusing together this is true not only of ice but of any material.
it's called sintering and it is caused by diffusion and a lowering of the surface energy.
This process is faster when the material is near it's melting temperature and faster yet if in contact with any miscible liquid phase.