The Speed of God

Over in Twitter-land, Eric Weinstein is visiting the AMNH at the same time as a bunch of Orthodox Jews, and takes the opportunity for a little Q&A:

Me: Excuse me, but how is the phylogenetic tree reconciled with Torah.

Modern Orthodox Man: Lorentzian time dilation. It’s a head hurter.

This is an interesting attempt to square the six-day creation story with modern science, and raises one obvious question: How fast must God have been moving for the six days of creation to last 13.7 billion years?

This is veering into Built on Facts territory, but the relevant formula is:


For six days (5.18×105 seconds) to seem like 13.7 billion years (4.32×1018 seconds), the Lorentz factor γ would need to be 8.34×1012. Solving this for the relative speed as a fraction of the speed of light tells us that God must be moving at:

vGod = 0.99999999999999999999999999281254 c

That’s only 2.15×10-16 m/s short of the speed of light. So God would trail a beam of light by only 1.12 million meters at the end of creation.

Starting from rest, this would require a total energy of 7.5×1029 joules per kilogram of God-mass to get up to speed. If you had expended that kind of energy, you’d rest of the seventh day, too.

(You might try to claim that God’s mass should be zero, given that He is insubstantial. This can’t be true, though, as if His mass were zero, He would necessarily be moving at exactly c, the speed of light. In that case, the Lorentz factor γ would be infinite, and no time would have passed in God’s frame since the start of creation. For God to have experienced the creation taking a finite time, He must be moving at a speed below that of light, and this implies that God has a non-zero, albeit very, very small, mass.)

(If you were to suppose that God is subject to the GZK cut-off, lest He scatter inelastically off photons from the cosmic microwave background, this would imply that God has a mass of 10-29 kg. But that would just be silly…)