"Time grain" seems like the wrong word here I will replace it with something more specific. Thank you for pointing this out and if you still dispute my math I would consider it helpful to hear why :)
I think he's talking about the ratio of a microsecond to a half hour to express scale, a microsecond to a half hour is approximate (to an order of magnitude) to 10^9.
1000000 (microseconds/second) * 60 (sec/min) * 30 (min for a half hour) =
1800000000
Ok. I was just extrapolating out that if from a microsecond to a half hour 10^9 which is within a couple of orders of magnitude of the age of the universe in seconds, then from a microsecond to a year would result in a ratio that when expressed as an integer is much larger than the age of the universe.
I'm realizing as I type this that I am not totally clear here and I will do some reflection now as to how to rewrite this point so it does not raise such objections. Thank you again for your help with this.
But I am talking about scale. The number of different size "bricks" or "units" of time that you can choose in which to execute concurrent or dependent logic is staggering. And all too often this is overlooked. Thus "February 29 bugs" and "New Years Day" bugs, not to mention the entire error classes of race conditions and cascading failures.
See here: http://infiniteundo.com/post/117192619718
"Time grain" seems like the wrong word here I will replace it with something more specific. Thank you for pointing this out and if you still dispute my math I would consider it helpful to hear why :)