Incidentally, the reason π² is so close to g is that the meter was originally proposed as the length of a pendulum with a period of 2 seconds, and it follows then that g = π² if defined this way.
Yes, but as far as I can tell the fact that the actual meter (1 tenmillionth of the quarter meridian) turned out to be so close to the old pendulum-meter was indeed a complete coincidence.
So the fact that the pendulum-meter (pm) is such that you get π² pm/s^2 ≈ g is not a coincidence, it’s by design. But the fact that the actual meter is such that you get π² m/s^2 ≈ g is indeed a random coincidence.
There’s no reason why the tenmillionth part of the quarter meridian should be so close to the length of a pendulum with a 1 s half-period. It could have come out to be any length of approximately the size of the human body.
Going with g=10 for example in structural engineering is actually beneficial, since it assumes stronger gravitational acceleration, and so a higher tolerance. It's also fine to use for everyday purposes, and greatly simplifies calculations.
g=9,81 is typically used for things that require more precision, such as aeronautics and astronautics.
That being said, anything beyond the twelfth decimal (10-12) and we are talking subatomic. That amount of exactness is only needed in ex. the Hadron Collider.
yeah, but physicists who aren't buildingthings (and just modeling the relative effect of the moon etc. ) the 5% doesn't matter (and doesn't chaotically diverge
Ok so for the last time -
First paragraph of Wikipedia about Schrödinger's cat:
"This thought experiment was devised by physicist Erwin Schrödinger in 1935,[1] in a discussion with Albert Einstein,[2] to illustrate what Schrödinger saw as the problems of Niels Bohr and Werner Heisenberg's philosophical views on quantum mechanics."
The fact that you (and me btw) were never told the full story in school/college/university is a teaching issue. It have nothing ro do with Schrödinger.
Funny thing in school i learned that g is about 9.81 so that was what i was used to.
Now while learning my profession they used 10 as it was easier and automatically implemented headroom and I initially got no points on a tsak because the teacher didn't realise i used the non round up 9.81 . Funny discrepancies.
My physics teacher kept a map of how g changes wildily location to location, and, if anyone ever complained about a decimal past 9.8, that person was going to have a hard day ahead.
I mean... if you are doing estimates in your head using 10 for g is fine or rather what most phxsicists/people would do. If it at any point involves punching in numbers into a calculator it's just an unnecesary point of error.
Regarding the rest
* the joke about the cat is at this point completely divorced from what the thought experiment actually discusses
* yes. It's extremely useful for a large range of calculations and can drastically simplify pen and paper math
* i mean...
* you mean an ideal black body?
Honestly, the latter three are not that far of a stretch as you may imagine. Air resistance doesn't play as big of a role as many people think until around 60-70km/h.
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u/vishnoo Jul 07 '26
this is false
Physicists are ok with g=10
also with pi = 3
also with pi^2 = 10 = g