5 ms·
> ”Rather than rely on a platinum cylinder in a bell jar in Paris, eggheads in the world of measurements decided to anchor the future kilogram to Planck’s const
by soneca 3y ago
> ”Rather than rely on a platinum cylinder in a bell jar in Paris, eggheads in the world of measurements decided to anchor the future kilogram to Planck’s constant. This is a fixed quantity tied in with E=MC2 and quantum theory, specifying the amount of energy carried by a single particle of light, or photon. And that’s just the most extremely simplified version.”
Can someone provide a not-so-simplified version that is still understandable by a layman of the current definition of a kilogram?
- mikewarot 3y agoI think that was a premature decision we'll eventually have to reverse. Just as fixing the speed of light, things might not be as constant as current theory states it is.
- Vecr 3y agoWhat would you do instead? The silicon sphere idea? It's not like hauling around physical kilograms is going to be any better.
- pvg 3y agoAnother comment mentioned it but the instrument used has a decently detailed Wikipedia page: https://en.wikipedia.org/wiki/Kibble_balance https://en.wikipedia.org/wiki/Kibble_balance The name and appearance might make you think it's some sort of flux capacitor for dogs but that is apparently not its (primary) purpose.
- perihelions 3y agoThat's some deeply unfulfilled nominative determinism potential. edit: unless kibble is cognate to quibble, and precision metrology is the ultimate form of quibbling?
- pvg 3y agoLooks like the etymology of 'kibble' is unknown, much like the etymology of 'dog' so the whole thing is definitely suspicious. https://www.etymonline.com/search?q=kibble https://www.etymonline.com/search?q=kibble
- kevmoo1 3y agoThis is THE explanation. It's long, but it's AMAZING! https://www.youtube.com/watch?v=KBZD3tFny_E https://www.youtube.com/watch?v=KBZD3tFny_E