# Shisha Veshishim Umeya - mi yodeya?

## Who knows one hundred sixty-six?

Please cite/link your sources, if possible. At some point at least twenty-four hours from now, I will:

• Go on to the next number.

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The sun is 166 times the size of the earth (plus change). - Rambam, preface to Commentary on the Mishna

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What "size" quality does this refer to? The mass, volume, and cross-sectional area ratios between these bodies are both orders of magnitude greater than 166. The closest I can think of is the ratio of their diameters, which contemporary observation puts at ~109. Was the Rambam referring to some other ratio, depending on observations that have since been revised, or depending on non-observational (e.g. Scriptural) data? wolframalpha.com/input/?i=diameter+of+sun+%2F+diameter+of+earth (Square for an area ratio. Replace "diameter" with "mass" or "volume" to get those ratios.) – Isaac Moses Jan 13 '11 at 19:45
The Lubavitcher Rebbe zt"l explains (see chabad.org/library/tanya/tanya_cdo/aid/7993/jewish/…) that the Rambam was referring to the sun's diameter, and including the protuberances and other such temporary phenomena (whereas the modern figure of ~109 refers to just the photosphere). – Alex Jan 13 '11 at 23:01
Interesting! Any kid who draws a picture of the Sun makes sure to include the shiny points coming out. I wonder why the Rambam used such a precise figure to describe a body with such variable size. – Isaac Moses Jan 14 '11 at 16:37
@Isaac: the "shiny points" in your average kid's (or adult's, for that matter) drawing are meant to represent the sun's rays, not the solar flares and whatnot. :) Anyway, as for the precision of the Rambam's figure: could be, according to this explanation, that it's simply an average obtained by observation over a long period of time. (Nowadays we would probably round to the nearest significant figure or two in order to make it clear that it's an approximation, but likely as not that wasn't the usual practice in earlier times.) – Alex Jan 14 '11 at 17:52

And, bitul b'rov is generally accepted as 1/60, which is 1.66% ;) .

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This would be a better answer for "Shishim - mi yodyea"? Also, note that shishim and rov are two different standards. – Isaac Moses Feb 25 '15 at 20:43
Some people don't appreciate clever answers. Harumph! – yaacov Mar 4 '15 at 2:54

There is a lot of talk about the Christians censoring 166 years of the Jewish calendar. That would mean we only have 63 years left till the year 6000.