T.R | Title | User | Personal Name | Date | Lines |
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880.1 | definitely infrequent | ZFC::DERAMO | I am, therefore I'll think. | Wed Jun 01 1988 12:28 | 5 |
| A blue moon being the second full moon of a calendar
month. For example, there were full moons on both 5/1/88
and 5/31/88.
Dan
|
880.2 | | BEING::POSTPISCHIL | Always mount a scratch monkey. | Mon Jun 06 1988 09:17 | 27 |
| Re .0:
Figure that the moon is full about every 29.5 days. In 28-day or
29-day months (one in 12), a second full moon cannot occur. In 30-day
months (5/12), a second full moon occurs if the first falls within the
first .5 days (assuming you require the exact moment of the second full
moon to be within the month), so that happens in .5/29.5 of the 30-day
months. In 31-day months (6/12), it's 1.5/29.5.
The chance of an average month containing a second full moon is (0*1/12
+ .5*5/12 + 1.5*6/12)/29.5 = 23/708. Second full moons occur about
every 30.8 months.
Non-math digression follows.
-- edp
A blue moon is not the second full moon of a month. Webster's defines
"once in a blue moon" as a rare period, arising from the fact that
atmospheric particles occasionally result in a blue tint to the moon.
Citations from literature concur: Daniel Herbert Lawrence wrote "once
in the _bluest_ of blue moons". If a second full moon is a blue moon,
what is the bluest of blue moons? I looked up a total of five
citations of use of "blue moon" by various authors; none used it to
mean the second full moon of a month.
|
880.3 | it's when you paint your butt blue, and ... | ZFC::DERAMO | I am, therefore I'll think. | Mon Jun 06 1988 11:21 | 19 |
| On the radio and tv the day of the blue moon, it was
described as being when atmospheric conditions give it
a blue color by an astronomer and as the second full
moon of the month by everyone else [the anchors were
probably just repeating what the weatherman said]. The
specific dates listed in .0 probably refer to the definition
in .1 as opposed to the one in .2. :-)
There is a neat "sci fi" story about a place where some
factory releases a chemical that causes the moon to look
blue, and all sorts of once-in-blue-moon type things
start to happen.
The first time difference in .0 is a little longer, the
second is in better agreement with the figure derived
in .2.
Dan
|
880.4 | Blue Moon rathole... | CHOVAX::YOUNG | Dumb, Expensive, Dumb ... (Pick Two) | Mon Jun 06 1988 13:33 | 20 |
| Re .2,.3: "Blue Moon" origin controversy...
It seems that this is something of a wide controversy concerning
the origin of this phrase. The best explanantion for the 2 different
claims that I have heard, is that when Krakotoa blew in the 1800's
it threw up enough particles into the upper atmosphere that the
full moon at the end of that month appeared Blue. It also just
happened that that was the second full moon of that month.
I have never heard any academic verification of this story, maybe
someone could post in JOYOFLEX(?) and see what comes out?
Re .3: Blue Moon story:
That was "Blued Moon" by Connie Willis, published a year or so ago
in Isaac Asimov's Science Fiction magazine. A VERY funny story
that was nominated for several awards (cannot remember if it won).
-- Barry
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880.5 | Moon-Cycle | HAMCL3::KEMMANN | | Tue Jun 07 1988 05:28 | 6 |
| Re .2 : for Your info:
the moon-cycle is 29.53059 days.
I used this number for calculation of Easter-Sunday.
I got this number from a customer, where we had to install
an automatic calendar-calculation.
regards Thomas.
|