The Einsteinian constant is not a constant, is not a center.
It is the very concept of variability – it is, finally, the concept of the game. In other words, it is not the concept of something – of a center starting from which an observer could master the field – but the very concept of the game.

A Mathematician Reads Social Text/Michael C. Sullivan
http://galileo.math.siu.edu/~msulliva/Preprints/soci...

Sokal's Hoax/Steven Weinberg
http://www.physics.nyu.edu/faculty/sokal/weinberg.ht...