More advanced slide rules typically have a set of “folded” scales, that can sometimes save a calculation from ending up off scale. In theory, these should be offset by half the scale length, i.e. sqrt(10). However, since the folded scales also offer a convenient way to multiply with the offset factor, most slide rules offset them by π instead, since it’s almost the same as sqrt(10), and multiplication by π is a more useful thing to have around.
lifthrasiir 4 hours ago [-]
The second fact, pi^2 ~= g, is famous enough that it has a separate section in Wikipedia [1].
I don’t see pi^2 ~= g in there… did I miss it somewhere?
renyicircle 4 hours ago [-]
My first thought was "well of course it is, since pi is a little larger than 3" but it was cool to see an actual derivation of how much pi squared differs from 10 as a nice, closed form series.
verzali 3 hours ago [-]
I remember discovering that pi x 10^7 is very close to the number of seconds in a year while at uni.
One of my tutors was convinced this had to be more than coincidence, but I always figured it was just chance and a nice but sometimes useful shortcut...
pansa2 30 minutes ago [-]
I always liked the fact that 10! (10 factorial) is exactly the number of seconds in six weeks.
You might be able to send someone down an amusing (to observers) rabbit hole of wrongness by telling them it is not exact because Earth’s orbit is not perfectly circular.
verzali 33 minutes ago [-]
Hah, that would be hilarious
GTP 2 hours ago [-]
You're such an evil person :D
simondotau 49 minutes ago [-]
It cannot be anything but coincidence. While 365.25 days in a year is physics, a day consisting of 86,400 seconds is an entirely arbitrary human construct.
Hnrobert42 2 hours ago [-]
Get enough numbers, accept wide error bars, and some of them are going to overlap.
leni536 3 hours ago [-]
This first became apparent to me when I got a slide rule. Pi is often marked on the various scales and an x^2 scale is often nearby the x scale.
BrandoElFollito 3 hours ago [-]
As an ex-physicist, pi^2 is 10. Like g.
I get it that this is a nice calculation with the Zeta function and everything, but 3 and a small something squared will be near 10 so it is 10.
wiz21c 41 minutes ago [-]
at this rate, pi square is close to 'g'
Dwedit 2 hours ago [-]
If you don't unblock scripts from cdn.jsdelivr.net.cdn.cloudflare.net, the math code won't work.
mac3n 47 minutes ago [-]
pi^2 ~ 10, well known to anyone who used slide rules.
Lerc 3 hours ago [-]
I was a little disappointed that the upper range of gravity on earth only goes to 9.8337. Just a little more and there would have been somewhere on earth that was an exact match.
It would have been the ideal (if chilly) place to start a cult.
gntech 44 minutes ago [-]
987654321 / 123456789 = 8 (to the 7th decimal place) is another nice one
awinter-py 2 hours ago [-]
need a countdown for when it gets there
amelius 1 hours ago [-]
Pi^0 is exactly 1.
skatedbear 57 minutes ago [-]
You could be on something there.
amelius 10 minutes ago [-]
I also noticed that e^(i*pi) gives an integer exactly.
smitty1e 4 hours ago [-]
The author wants tau=2*pi, but in the Greek alphabet, tau has one vertical stroke, and pi has two.
So, visually in Greek, pi=2*tau would seem an improvement.
pi's prevalence instead of tau is one of the strongest indicators that we live in a suboptimal timeline.
GTP 2 hours ago [-]
Then, convert the digits of pi to text to find how to achieve interdimensional travel to reach the optimal timeline.
alfiedotwtf 48 minutes ago [-]
Millions of years from now, a far off alien race will discover the remnants of Earth, go through our maths knowledge, and they will slap their foreheads because we chose pi rather than tau.
Edit: I just remembered I have public JupyterLite notebooks for both of these:
https://notebooks.oranlooney.com/lab/index.html?path=fake_ma...
https://notebooks.oranlooney.com/lab/index.html?path=heegner...
[1] https://en.wikipedia.org/wiki/Mathematical_coincidence#Gravi...
One of my tutors was convinced this had to be more than coincidence, but I always figured it was just chance and a nice but sometimes useful shortcut...
I get it that this is a nice calculation with the Zeta function and everything, but 3 and a small something squared will be near 10 so it is 10.
It would have been the ideal (if chilly) place to start a cult.
So, visually in Greek, pi=2*tau would seem an improvement.
Oh, well.