Happy Pi Day!
- Thread starter Trippin
- Start date
haha you're so square
One of my math teachers always used to say:
"Pi R squared, Pi R not round" :rofl:
Pi is handy in things other than trig.
I heard they used it to develop cryptographs for military applications. If you had stronger computers than the enemy, you could just state your "key" to break your code is the 8 numbers in Pi starting at position 1,345,251. So even if they found your "key", unless they could solve it quickly, the code could not be broken before you switched the "key" value.
Pi also is useful for describing the concept of significant digits. Let's say I know the diameter of a tire. It's 34.50" on the average. Sometimes they will measure as small as 34.46" or as big as 34.54". If I say the tire is 34.5" inches, I'm always right, since when you round 34.46-34.54 you always get 34.5". If I say the diameter is 34.46, 34.47, 34.48, 34.49, 34.50, 34.51, 34.52, 34.53, or 34.54", I would be wrong most the time.
So I have this diameter that is for certain, 34.5". If I want to find the circumference (rolling distance), I just multiply by Pi. Well Pi doesn't have an exact value. It's 3.14159... How "exact" does Pi have to be for me?
3.14 is good enough. Why? Since you didn't know the exact tire diameter, you had to use 3 numbers to represent it. The fourth digit was unreliable. So using the fourth digit of Pi (2) will have the same effect. I use more than 3 digits of Pi, the accuracy of my result will not improve, since the unreliable 4th digit of the diameter wipes it out. Nor will my answer for the circumference, 108" be any more accurate than 3 digits as well, since it could vary in the 4th place regardless of how many digits of Pi I use.
I call it fuzzy math.
I heard they used it to develop cryptographs for military applications. If you had stronger computers than the enemy, you could just state your "key" to break your code is the 8 numbers in Pi starting at position 1,345,251. So even if they found your "key", unless they could solve it quickly, the code could not be broken before you switched the "key" value.
Pi also is useful for describing the concept of significant digits. Let's say I know the diameter of a tire. It's 34.50" on the average. Sometimes they will measure as small as 34.46" or as big as 34.54". If I say the tire is 34.5" inches, I'm always right, since when you round 34.46-34.54 you always get 34.5". If I say the diameter is 34.46, 34.47, 34.48, 34.49, 34.50, 34.51, 34.52, 34.53, or 34.54", I would be wrong most the time.
So I have this diameter that is for certain, 34.5". If I want to find the circumference (rolling distance), I just multiply by Pi. Well Pi doesn't have an exact value. It's 3.14159... How "exact" does Pi have to be for me?
3.14 is good enough. Why? Since you didn't know the exact tire diameter, you had to use 3 numbers to represent it. The fourth digit was unreliable. So using the fourth digit of Pi (2) will have the same effect. I use more than 3 digits of Pi, the accuracy of my result will not improve, since the unreliable 4th digit of the diameter wipes it out. Nor will my answer for the circumference, 108" be any more accurate than 3 digits as well, since it could vary in the 4th place regardless of how many digits of Pi I use.
I call it fuzzy math.
