Re: Why borrow 'seven'? (was: IE right & 10)

From: tgpedersen
Message: 34268
Date: 2004-09-24

--- In cybalist@yahoogroups.com, enlil@... wrote:
> Torsten:
> > How would you correlate 3 groups with the appearance of the moon?
>
> Exactly. Everybody knows that the length of a lunar cycle from new
> moon to new moon is approximately 7*4 days long. It's easier for
> people to use integers rather than fractions and we see that we
> can get nice even numbers that approximate the cycle in this way.
>
> We can do this for any cycle. The yearly cycle is approximately
> 365 days long. That can be divided up with integers too. In fact,
> we use the same integer 7. We all know that there are 52 weeks in
> a year. So 52*7 days approximates the year nicely and by using the
> same integer as the lunar cycle ("7"). Now 52*7 is really 13*4*7 and
> since we see that 4*7 is a month, we might choose to seperate the
year
> by 13 months -- note 13*(4*7).
>
>

Thank you. Unfortunately, in the meanwhile I remembered that the
Romans actually did divide the month into three periods (Ides,
Kalends, and I forgot the third).

Torsten