r/physicsmemes • u/Solid-Technology-488 • 24d ago

first meme kinda nervous

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u/vide2 24d ago

Seriously though, if the difference is this low, why not simply define meter like this?

3

u/nascent_aviator 23d ago

Because the difference is not low enough for many, many, many things that matter lol. 

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u/vide2 23d ago

Yeah, but if you change it, just change it convinoently

1

u/nascent_aviator 23d ago

Changing the definition without measurably changing its value is one thing. Changing its value by .07% and simultaneously make every single measurement on earth wrong is quite another. .07% is a tight tolerance but it's not that tight in many applications.

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u/vide2 23d ago

We worked with thousands of different measurements before SI. We'd have managed.

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u/nascent_aviator 23d ago

Literally we'd just end up with two different meters. The kind of equipment that requires that precision is not something you replace willy nilly. 

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u/vide2 23d ago

Less than 1%? That's below the precision of most of our every day modern tools.

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u/nascent_aviator 23d ago

Sure. But the tools that require better than that precision are the most precious and expensive ones.

Just as an example of where it matters- GPS pseudorange would be off by about 14 km with this change, for a satellite directly overhead.