The Picard ManeuverApr 3

The speed of light

https://lemmy.world/post/45114697

Show threadZwiebel
Because we tried to make the meter one 40millionth of the earths circumference, failed, and ended up at
Apr 3 at 3:15pmWeb
Show threadwhosepoopisonmybuttocksApr 3
Well, in our defense, we’re very small.
Show threadBibipApr 3
Ent verified, ent approved
Show threadWhiskyTangoFoxtrot6d ago
Are you sure?
Father Ted: 'Small' vs 'Far Away'

YouTube
Show thread_stranger_Apr 3

At least one second has a simple origin, and totally wasn’t back-defined in 1967

oh wait

The current and formal definition in the International System of Units (SI) is more precise:

The second […] is defined by taking the fixed numerical value of the caesium (Cs) frequency, ΔνCs, the unperturbed ground-state hyperfine transition frequency of the Cs-133 atom, to be 9192631770 when expressed in the unit hertz, which is equal to s−1.[1]

Show threadmercApr 3
Having said that, we’re pretty lucky that using those pretty arbitrary values we ended up with a speed that you can approximate as 300 million m/s and be off by less than 0.1%.
Show threadJackbyDev6d ago
My understanding is that the person proposing the meter’s distance immediately caught their mistake but didn’t bring it up because they didn’t want people to think the system was flawed, not so much that the measurement was off.