Thursday, June 14, 2007


(A repost from something I've written elsewhere)

יומו של הקב"ה אלף שנים שנא' כי אלף שנים בעיניך כיום אתמול
A day to God is a thousand years, as is said: "For a thousand years in your sight are like a day that has just gone by"

So I read the above and think (yeah, yeah, I shouldn't do that, I know): exactly at what speed is God traveling to achieve this kind of time dilation? And given that, how big a distance did God manage to travel so far?

For simplicity's sake, let's assume for now that God is traveling at constant velocity. (I think -- but may be mistaken -- that we can achieve a more dramatic effect if we have God maintaining constant acceleration. But I'm not sure even a deity can sustain that indefinitely.) Also, let's discount the possibility that God is permanently parked right next to a black hole (although that would explain a lot).

For starters, I'm trying to get a Lorentz transformation calculator working. But I'm woefully ignorant on how exactly I should deal with velocity figures. My calculator doesn't understand v. ;-) So, anyone else ever wondered about this question? (Thought so.)

Why I need to know God's speed, you ask? Well, first of all, as Orthoprax knows, we need to know these things. "If the issue is important to [us], then practically we cannot let it remain undecided." But mostly, I'd really like to know if I can beat Her in a race to the End.

Update 1:
Since nobody offered to help, I was forced to think about it some more. We need to express v in terms of the speed of light, of course! Duh, what a stupid question.

Since a mean Hebrew year has 365.2468 days, we need a time dilation factor of 365,246.8.

So, to simplify {1day / sqrt(1- v^2 / c^2) } into {1/ sqrt(1- 0.999999999996251^2)} (we take c=1 to simplify the calculation) gets us pretty close. That means God is traveling at (approximately) 299,792,457.998876 meters per second, or 670,616,629.381881 m.p.h., right?

Hmmm, I think I may need a new minivan if I hope to beat that!

Update 2:
All this further means, of course, that to find the speed necessary for any time dilation factor f (in this case 365,246.8), all we need to do is {sqrt(1- (1/f)^2)c} (simple, huh?), which, with c expressed in meters per second of 299,792,458, gives us the correct answer of 299,792,457.998876! (And also yields a more accurate figure for v: 0.999999999996252)

Was it that difficult to say {sqrt(1- (1/f)^2)c} instead of letting me figure it all out with pen and paper??? Gee, thanks! ;-) So now, how about we add acceleration into the mix? Anyone?

P.S. To those who inquired (or wondered but didn't inquire): the picture on the previous post is not of a real person, but rather of a larger-than-life sculpture by the incredibly talented artist Ron Mueck. Click here for a gallery of his work. (Warning: some images may be offensive to some. Proceed with caution.)