# Why there are constant numbers in the universe? [closed]

Why the ratio of a circle's circumference to its diameter is always the constant $\pi$? Moreover many of you know better than me about golden ratio $\phi$, Euler's number e, and many other constants. How explain this while everything seems to be in chaos? Is there any explanation for this kind of questions in physics?

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## closed as off topic by Waffle's Crazy Peanut, dmckee♦May 7 '13 at 16:53

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The fact you mentioned about circle is actually quite amazing. On the one hand you can draw a circle on your copy and check that ratio of circumference to the radius is constant. On the other hand you can begin with assumptions of set theory and develop real numbers, real plane and calculus from it purely on the base of logical reasoning; and then you find that mathematical circle is the same as physical circle that we observe in this world. Actually the similarity between the physical circle and the mathematical (flat) circle has to do with the fact that curvature of our space is quite small. –  user10001 May 6 '13 at 18:23
I think this two questions on Math.SE would be interesting: Does π depends on the norm? and π in arbitrary metric spaces. –  m0nhawk May 6 '13 at 18:35

$\pi, e,$ and $\gamma$ are all mathematical constants. They are not dependent on the physical universe. For example,
$$\pi = 4\left(1 - \frac{1}{3} + \frac{1}{5} - \frac{1}{7} + \ldots\right)$$