Wednesday, February 4, 2015

ambiguity in the Planck-units?

the Planck-units are defined using the great constants of Nature: $c$ from relativity, $\hbar$ from quantum mechanics, $k_B$ from thermodynamics and finally $G$ as the gravitational coupling constant. but gravity brings a long a second coupling constant, the cosmological constant $\Lambda$, which now makes the Planck system of units overdetermined: is there a way to resolve this?

1 comment:

  1. CQW thinks that this is a tricky one: at first sight, yes, they're ambiguous, as one can define a Planck-system using $c$, $G$ and $\hbar$ as well as a Hubble-system with $c$, $G$ and $\Lambda$. On the other hand, we might understand some day how both $G$ and $\Lambda$ follow from a more fundamental theory, of which general relativity is the limit of small self-interaction of the gravitational field.