also, bonus connections: kl divergence is the ln of the lorentz factor (log(gamma)), the Bhattacharyya coeeficient is 1/gamma, and Jeffreys divergence is veloci

also, bonus connections: kl divergence is the ln of the lorentz factor (log(gamma)), the Bhattacharyya coeeficient is 1/gamma, and Jeffreys divergence is velocity times rapidity!