It's from _A Deepness in the Sky_. The actual epoch chosen was the time of the first moon landing, a little prior to 1-Jan-1970 (I like this touch, something w

It's from _A Deepness in the Sky_. The actual epoch chosen was the time of the first moon landing, a little prior to 1-Jan-1970 (I like this touch, something with actual historical significance and likely documentable to a fraction of a second, rather than an arbitrary date).