posted on Jan, 24 2019 @ 09:52 AM
a reply to:
DpatC
Pi is not 3.1416, 3.1415, or even 3.1415927 as FCD remembers it. Pi has no solution; it is a number that never repeats or ends after the decimal
point. We have to approximate it because of this, if we want to get real numbers. It is defined as a physical constant: the ratio of a circle's
circumference to its diameter. The more accurate our measurements get, the more evidence we have that it can never be stated exactly in our base 10
number system.
If one were to take a perfect wheel of exactly 1 unit in diameter (does not matter what that unit is; it can be an inch, a centimeter, a foot, a
meter, a yard, or a mile) and measure the distance around it exactly, it would be pi units. That's all pi is: just a number that we can't seem to get
exactly. We use pi in calculations because we can then use the calculations to get the accuracy we want just by putting in a more accurate number for
pi. For example, if I know the tire on my car is 2 feet in diameter, I can multiply that by pi to find out how far my car will go every revolution of
the wheel. I might be good with using 3.14 and get the needed accuracy, or I might need to be more accurate and use 3.1416, or even 3.1415927. Heck, I
sometimes do rough calcs in my head using pi=3... kinda inaccurate, but I can make it more accurate when I get to a calculator.
Wheels have been used all across the planet, being one of the earliest discoveries, so pi appears all across the world in various ways. That's really
all there is to it. There's nothing mysterious or earth-shaking about pi. Sometimes it is just easier to measure something as "37 revolutions of this
wheel."
TheRedneck