I understand the difference betw mathematical and physical pi. I also understand that in non-Euclidean space the value of pi would differ depending on a surface's deviation from flatness.(adsbygoogle = window.adsbygoogle || []).push({});

But is there a different symbol for physical pi, to distinguish it from mathematical pi? Because I don't understand how pi works in the Einstein field equations (e.g., see: http://en.wikipedia.org/wiki/Einstein_field_equations)

I'll ask a very naive question about these equations:

does the pi in those equations have a variable value? in other words, if you were to replace pi with its mathematical value, would you get those equations wrong? ( or is there some part of the equations that makes pi change depending on curvature? or is there a different set of equations where pi variability is applicable??)

I am trying to figure out how to properly answer someone who claims: "But pi shows up in Einstein's field equations, so how can you say pi doesn't quite apply in relativity?"

I hope I have made my dilemma clear. I'd so very much appreciate help with this. I'm trying to explain these concepts to somebody (a case of the one-eyed leading the blind), and I don't want to misinform them.

Thank you.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Pi and Einstein field equations

**Physics Forums | Science Articles, Homework Help, Discussion**