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In the 'Frontiers in Astrophysics' course on Open Yale, professor Bailyn says that, for the purpose of the course, pi = 3, and pi^2 = 10. Pi = 3, coincidentall
by sago 11y ago
In the 'Frontiers in Astrophysics' course on Open Yale, professor Bailyn says that, for the purpose of the course, pi = 3, and pi^2 = 10.
Pi = 3, coincidentally, is the Hebrew Bible's approximation too.
- CydeWeys 11y agoWhen I took astronomy, anything within an order of magnitude (10) was considered to be the same number. Calculations are very easy when you're only worrying about the number in the exponent.
- tamana 11y agoIn astronomy, you only need to get the order of magnitude right to within an order of magnitude.
- archgoon 11y ago"Everything is linear if plotted on a log-log plot and with a fat enough magic marker." - Mar's Law
- sp332 11y agoFeynman was talking to some students, and he used some historical event as an illustration, but he got the date wrong by a few years and they called him on it. He laughed and said "Hey, three decimal places is pretty good for a theoretical physicist!"
- KMag 11y ago> Pi = 3, coincidentally, is the Hebrew Bible's approximation too. Certainly it's not explicitly spelled out. The example I've heard was the outer diameter and inner circumference of a vessel's circular rim were given. Pi comes out to 3 only if the thickness of the rim of the vessel is zero.
- lotharbot 11y agoeven if the measurements were both outer measurements, the actual value of pi is within the typically assumed error bounds (30/10 < pi but 30.5/9.5 > pi.)
- sago 11y agoYes I was over-egging the cake. It is a large cast bowl in 1 Kings 7:23ff. It's beloved of a certain kind of 'gotcha' internet skeptic "Proof that the bible thinks Pi is 3 !!1! How dumb are teh Christians!". But the passage itself even mentions the thickness of the bowl, and there's no reason to assume the numbers are anything more than a description of a particular bowl (which inevitably wouldn't have been perfectly circular).
- deleted 11y ago[deleted]
- rzzzt 11y agoThere were some exercises in our high school physics textbook which required you to simplify a fraction by assuming pi^2 = g.
- semi-extrinsic 11y agoAnother nice one is that there's pi*10^7 seconds in a year. Which is accurate to three decimal places.
- pklausler 11y ago"pi seconds are a nanocentury" is attributed to Adm. Grace Murray Hopper and it's surprisingly useful to know.