[Avodah] birchas hachama

[Micha Berger]

On Fri, Aug 29, 2008 at 12:08:17PM -0700, Eli Turkel wrote:
: Similarly five digit accuracy can be reasonable for small periods of time.
: Over the years and centuries the accumulated error is large. Thus the
: starting date for saying tal umatar is noticeably off.
: Similarly as we have discussed the dates for Pesach are occasionally
: getting very late because of error accumulation

Again, given that we say the very same berakhah on lightning, I don't
know why you assume astronomy is the defining feature. Lightning's brief
and startling flash reminds us of day 1 and the "or zarua' latzadiq"
the or ganuz. The rough approximation of getting the sun back to where
it was on a Wed is enough to remember yom revi'i.

But perhaps Abayei did assume there would be a Sanhedrin updating his
pesaq by now.

Tir'u baTov!
-Micha