[Avodah] birchas hachama

[Eli Turkel]

2- Tequfas Shemu'el is simply an approximation to the nearest 5 digits
for computing the March Equinox. And birkhas hachamah IS when that
approximate date is on Wed. I'm missing why you insist that we either
figure out when it was to more digits precision, or there is no point
to the berakahah at all.>>

For a measurement there is the error in the small and the accumulation of
error. Using 3 for pi is reasonable for small objects. When giving the
circumference of yam shel shelmoa the difference between 30 amot and 31+
amot is quite measurable.

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

As an aside in the courses I teach we make a big deal of the difference between
local computer errors and error accumulation. If a problem is ill-conditioned
then a small round off error can lead to catastrophic global errors

-- 
Eli Turkel