CSflim

Pi is as real as any other number. Just because it cannot be written down as a decimal does not change this. I don't know what you mean when you say we cannot know it's value. You can draw a line of length pi quite easily. But perhaps your objection is that it could never be exactly pi. Certainly, that's true. But it could never be exactly two either.

Also, pi is not a "social construct". There is a reason why were are beaming the encoded value of pi, and not the complete works of shakespeare, out into space to alert any extra-terrestrial life of our presence.

EDIT:
I know what you are saying, but just so as not to confuse anyone:

pi has only one value. Non Eucleudian cirlces do not have a circumference/diameter ratio of pi.

__________________