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[-] Melatonin@lemmy.dbzer0.com -1 points 1 year ago

I know the metre has been defined by earth's size, or other various things, all rather arbitrary. Wouldn't it make sense to define it by the speed of light and a light year, divided into even portions? Start by dividing a light year (in a vacuum) by ten, and keep dividing by ten until we get a unit that is close to the useful size we are accustomed to?

That way we could scale up, and I suppose that's going to be useful in the future.

[-] Kethal@lemmy.world 11 points 1 year ago

It's already defined that way - from Wikipedia "From 1983 until 2019, the metre was formally defined as the length of the path travelled by light in a vacuum in 1/299792458 of a second. After the 2019 redefinition of the SI base units, this definition was rephrased to include the definition of a second in terms of the caesium frequency ΔνCs. "

[-] Melatonin@lemmy.dbzer0.com 2 points 1 year ago* (last edited 1 year ago)

Just because it's defined as some section of a light year does not mean it's using a light year as a reference. You could use a foot and find the fraction of a light year that represents it, but that doesn't mean that the foot is based on a light year.

I'm saying the short measure that we use on a daily basis might be a BASE 10 portion of a light year. Not 1/299792458 of a light second.

P.S. It's like being on Reddit, being download for conjecturing.

[-] Kethal@lemmy.world 3 points 1 year ago

I see what you mean. That is just as arbitrary as using the Earth's size or any other reference. There's nothing special about a year.

[-] Melatonin@lemmy.dbzer0.com 2 points 1 year ago* (last edited 1 year ago)

Touché

My ignorance shows it's ugly face again.

[-] accidental@lemmy.sdf.org 1 points 1 year ago

it's a hard thing for me to wrap my head around, but it's cool when you think about it: there's actually no possible shared reference; even with atomic clocks, based solely on the bouncing of cesium atoms ticking away, the distance travelled is dependent on acceleration in your reference frame.

relativity really is!

this post was submitted on 26 Aug 2023
516 points (94.9% liked)

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