Fall 2008
Course: N 4502
Office Location: SCI 101
Office Hours on Campus: TH 6:15 PM-7:15 PM and only by appointment
Meeting hours: TTh 7:15 PM –10:20 PM
Telephone Number: (818) 366-2552
Email: kocharian_armen@smc.edu
Email: armen.kocharian@calstatela.edu
Department of Physics and Astronomy
California State University
18111 Nordhoff Street,
Northridge, CA 91330-8268
Phone: (818) 677-5203
Fax: (818) 677-3234
armen.n.kocharian@csun.edu
http://www.csun.edu/~akocha
Yes. π is a mathematical constant usually defined as the ratio of the circumference of a circle to its diameter in Euclidean geometry. It can also be defined in other ways; for example, it can be defined using an infinite series:
π/4 = 1 - 1/3 + 1/5 - 1/7 + 1/9 - . . .
In general relativity, space and spacetime are non-Euclidean geometries. The ratio of the circumference to diameter of a circle in non-Euclidean geometry can be more or less than π. For the types of non-Euclidean geometry used in physics the ratio is very nearly π over small distances so we do not notice the difference in ordinary measurements. This does not mean that π changes because our definition of π specified Euclidean geometry, not physical geometry. No new theory or experiment in physics can change the value of mathematically defined constants.