Meta-tool

Derivation Explorer

Click any of 18 constants on the left — see the full derivation chain from the SPT Toy Action down to the PDG/CODATA numerical value.

Speed of light

$c$

PASS

SPT prediction

2.99792458 \times 1 0^{8} m/s

Measured

2.99792458 \times 1 0^{8} m/s

1
SPT defines c as the membrane flip-rate: any pure flip mode propagates at exactly one membrane unit per τ.
$c \equiv \frac{1 membrane unit}{1 τ}$
2
From the photon dispersion ω = c k (toy 2), the slope of ω(k) at small k yields c numerically.
$c = \frac{\partial ω}{\partial k}_{k \to 0}$
$\Rightarrow 2.998 \times 1 0^{8} m/s$