@atoponce this is a lot more contrived but 100 has 3 digits and 100 in binary is 8; 100°F is 38°C.

Edit: Thanks to @mral for pointing out the mistake. Three zeros is 8 (1000₂) and not three digits. I actually think of 2³ =8 but figured I would explain it with binary and messed it up.

100 is 3 digits; 2³ is 8; so 100°F is 38°C, it's a longer walk but on the correct path 😂

@atoponce

There might be some more obscure scale where this is also true, but I _think_ temperature is the only thing where metric and imperial units can be converted with a simple (single-digit) ratio. That's because in 1777, the Royal Society redefined Fahrenheit to be exactly 180 degrees between freezing and boiling water — which, of course, is a 100 degree span in Celsius or Kelvin.

@atoponce If we're looking to be exact, that's incorrect. In fact, 16C equals 60.8F, and 28C equals 82.4F.

The two scales line up on whole-number equivalents every 5C (or 9F, which is the same thing). Thus 20C=68F, 15C=59F, &c., so 16C and 28C can't line up exactly with F.

The difference between C and F is the difference between decimal and sexagesimal; one divides freezing -> boiling into 100 degrees, and the other divides that interval into 180. Thus C/F = 5 to 9.

@atoponce While there was some fiddling, normal body temperature was set to be 98.6 degrees F, which is 37 degrfees C,. and 0 degrees F was the freezing point of a specific mixture of water and a salt (ammonium chloride). It might have made sense in the 18th century.

The Fahrenheit scale is used in the U.S. for the same reason that country still uses inches, feet, and pounds: if it was good enough for grandpa, it is good enough for me.