[Avodah] Q re tonight's RYReisman shiur on the chamah

[Micha Berger]

On Tue, Mar 24, 2009 at 12:30:29AM +0000, kennethgmiller at juno.com wrote:
: I suppose you are correct that a cycle doesn't have an *intrinsic*
: beginning point. But on the other hand, I think we can say that it does
: have a *specific* beginning point, and that this specific point can be
: defined by halacha, or agreed by convention, or both.

Or there are points that have significant events, such as the new moon.
A month could have been full moon to full moon, but half-moon to half
or some other point in the cycle is less probable. The new moon is the
obvious point, although I guess it could be the time total absence begins
(to the naked eye), ends, or the midpoint.

So, HQBH said it was the end of total absence that defines the time Rosh
Chodesh should average.

...
: The sun is a bit different. I'm not sure, but I think the four tekufos
: of the solar year are conventions, designed for agricultural purposes,
: such as when to pray for Tal Umatar...

They are also significant events in the cycle, or approximations thereof:
the time the sun is its most north, the time it's its most south, and
the two times it's in betweeen over the equator.

Yes, I'm sure someone could dream up other significant points, but it's
not entirely arbitrary.

All that said, RAM wrote the above in reply to my words:
:> Cycles don't have an intrinsic "start". There is no meaning
:> to "although the sun and moon may have been created in
:> Tishrei, the beginning of their cycles was actually the
:> equinox before - but it was a 'theoretical' equinox."
:> Without it being the actual time of creation, what makes
:> one point in a circle (oval, really) the beginning over
:> another?

What makes a vernal equinox a *beginning* of the cycle? Even given that
we have more reason to pick the starting point of a tequfah, why that
tequfah rather than the actual tequfas Tishrei that you're saying beri'ah
concluded on?

Tir'u baTov!
-Micha

-- 
Micha Berger             Man is a drop of intellect drowning in a sea
micha at aishdas.org        of instincts.
http://www.aishdas.org                         - Rav Yisrael Salanter
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