# The Naked Scientists Forum

### Author Topic: Moon question.  (Read 2491 times)

#### Don_1

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##### Moon question.
« on: 27/01/2009 12:27:59 »
Which is the only month in recorded history in which there was no full Moon?

#### lightarrow

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##### Moon question.
« Reply #1 on: 27/01/2009 12:42:52 »
Which is the only month in recorded history in which there was no full Moon?
When it's cloudy?

#### dentstudent

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##### Moon question.
« Reply #2 on: 27/01/2009 12:48:24 »
February?

#### Vern

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##### Moon question.
« Reply #3 on: 27/01/2009 12:51:30 »
Good ole Google seems to find that your original question may need work This is not in all of recorded history; but it seems like it happens with some regularity.

Quote
We calculated the dates and times of all of the Full Moons in the thousand years from 2000 to 2999 inclusive. There are 12,368 Full Moons during that period, and 952 of them are in February.

Since a thousand years must include a thousand Februaries, it is obvious straight away that 48 of those Februaries are missing a Full Moon.

Counting the number of Full Moons which fall in February in a leap year, we find 240 of them.

However, the thousand-year period from 2000 to 2999 has 243 leap years. (Remember that in the Gregorian calendar, century years are only leap years if they divide by 400, so 2100 will not be a leap year, and nor will 2200, 2300, 2500, 2600, 2700 and 2900.)

So there are 243 leap years, but only 240 of them have a Full Moon in February. This means that there will be just three leap years in which February will have no Full Moon.

Those years are 2572, 2792 and 2944.

It turns out that in those three years, both January and March have two Full Moons, but that isn't surprising since a 29-day February can only miss out on a Full Moon if there is a Full Moon late on January 31st. That, in turn, means that there must have been a Full Moon in early January, and it also means that the next Full Moon must be early on the morning of March 1st, thus March will also have a Full Moon at the end of the month.

#### Don_1

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##### Moon question.
« Reply #4 on: 27/01/2009 13:20:50 »
Bugger!

Seems you're right Vern.

I take that question back.

?nooM lluf on saw ereht hcihw ni yrotsih dedrocer ni htnom ylno eht si hcihW

Back to the drawing board.

#### lyner

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##### Moon question.
« Reply #5 on: 27/01/2009 13:32:55 »
In the same vein, in some part of the world, at midsummer, there will be two longest days, sandwiched by the shortest night. And, at particular longitude, there will be two equal shortest nights and one longest day. In both cases there is a symmetrical situation.

#### Vern

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##### Moon question.
« Reply #6 on: 27/01/2009 13:55:29 »
Bugger!

Seems you're right Vern.

I take that question back.

?nooM lluf on saw ereht hcihw ni yrotsih dedrocer ni htnom ylno eht si hcihW

Back to the drawing board.
No; the question still works; and the second answer you got was correct. You didn't say that it just happened once as I originally gleaned. It was just one month that may happen more than once.

#### Don_1

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##### Moon question.
« Reply #7 on: 27/01/2009 14:09:56 »

As to this new question from SC, are there actually names given to these places, or are they just points of long/latitude?

#### DoctorBeaver

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##### Moon question.
« Reply #8 on: 28/01/2009 00:15:03 »
In the same vein, in some part of the world, at midsummer, there will be two longest days, sandwiched by the shortest night. And, at particular longitude, there will be two equal shortest nights and one longest day. In both cases there is a symmetrical situation.

I used to live right on the equator and we had 2 longest days each year - once when the sun passed the equator on its way north, and then when it went back south. Similarly, there were 2 shortest days when the sun was at each tropic.

#### The Naked Scientists Forum

##### Moon question.
« Reply #8 on: 28/01/2009 00:15:03 »