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Re: Moon was produced by head-on collision?

From willner@cfa.harvard.edu (Steve Willner)
Newsgroups sci.astro, sci.physics
Subject Re: Moon was produced by head-on collision?
Date 2016-02-11 19:44 +0000
Organization Harvard-Smithsonian Center for Astrophysics
Message-ID <n9ioa1$657$1@dont-email.me> (permalink)
References (8 earlier) <56B42852.31BE@ix.netcom.com> <n92eu8$lu2$3@pcls7.std.com> <n92fmr$h9b$1@odin.sdf-eu.org> <n935ca$quk$1@dont-email.me> <n938vn$2sk$1@gioia.aioe.org>

Cross-posted to 2 groups.

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In article <n938vn$2sk$1@gioia.aioe.org>,
 Martin Brown <|||newspam|||@nezumi.demon.co.uk> writes:
> I am sceptical too but here is one source with references:
> http://www-das.uwyo.edu/~geerts/cwx/notes/chap10/moon.html

I looked at the notes but not the references.  They refer to single
locations and limited periods of time, which makes me wonder about
statistical significance.  In any case, they can't tell us anything
global.

> There is a more recent climate related paper claiming a statistically 
> significant temperature to lunar phase correlation in satellite data but 
> not rainfall.
> http://science.sciencemag.org/content/267/5203/1481.abstract
> 
> It isn't totally implausible since the Earth will be very slightly 
> closer to the sun at full moon. The effect is tiny ~20mK

I think Martin has nailed the cause, though the authors didn't. While
the authors write "0.02 K" and "0.03 K" in the text -- and why they
give two different values is unclear to me -- their Figure 1 (which I
found in the pdf but not the html version) actually shows 10 mK
difference. That's just the amount I estimate from the difference in
solar distance as a function of lunar phase.  I'm impressed that it
can actually be measured.

Another source quoted
http://www.reportingclimatescience.com/news-stories/article/lunar-gravity-affects-rainfall.html
which is based on the refereed article at
http://onlinelibrary.wiley.com/doi/10.1002/2015GL067342/full

This shows the expected semi-diurnal tidal effect on the atmosphere
and correlates it with a tiny rainfall effect.  The original claim
was a monthly effect, which this paper doesn't address and about
which I remain skeptical.

By the way, it's not hard to compare the relative tidal forces on a
raindrop from the Moon and from a nearby frog.  The Moon is roughly
three times denser than a frog, so if the Moon and the frog subtend
the same angular diameter as seen from the raindrop, the Moon's tidal
force will be three times larger.  Move the frog 30% closer, and the
tidal forces will be equal.  (Tidal force goes as r^-1/3.)  Of course
both are utterly negligible for any practical purpose.

-- 
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner            Phone 617-495-7123     swillner@cfa.harvard.edu
Cambridge, MA 02138 USA                 

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Thread

Moon was produced by head-on collision? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2016-01-30 19:55 -0500
  Re: Moon was produced by head-on collision? Sam Wormley <swormley1@gmail.com> - 2016-01-30 22:17 -0600
  Re: Moon was produced by head-on collision? dlzc <dlzc1@cox.net> - 2016-01-31 07:25 -0800
  Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-01-31 09:44 -0800
    Re: Moon was produced by head-on collision? dlzc <dlzc1@cox.net> - 2016-01-31 17:02 -0800
    Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-01-31 23:10 -0800
      Re: Moon was produced by head-on collision? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2016-02-01 03:13 -0500
        Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-01 10:36 -0800
  Re: Moon was produced by head-on collision? willner@cfa.harvard.edu (Steve Willner) - 2016-02-01 22:27 +0000
    Re: Moon was produced by head-on collision? Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2016-02-01 19:44 -0500
      Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-01 23:12 -0800
        Re: Moon was produced by head-on collision? dlzc <dlzc1@cox.net> - 2016-02-02 05:57 -0800
        Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-02 15:59 -0800
          Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-02 22:14 -0800
            Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-03 14:23 -0800
          Re: Moon was produced by head-on collision? Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2016-02-04 11:40 +0000
            Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-04 11:35 -0800
              Re: Moon was produced by head-on collision? moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-02-05 03:18 +0000
                Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-04 20:42 -0800
                Re: Moon was produced by head-on collision? Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2016-02-05 08:46 +0000
                Re: Moon was produced by head-on collision? moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-02-05 15:26 +0000
                Re: Moon was produced by head-on collision? R Kym Horsell <kym@kymhorsell.com> - 2016-02-05 15:39 +0000
                Re: Moon was produced by head-on collision? dlzc <dlzc1@cox.net> - 2016-02-05 12:55 -0800
                Re: Moon was produced by head-on collision? willner@cfa.harvard.edu (Steve Willner) - 2016-02-05 21:48 +0000
                Re: Moon was produced by head-on collision? R Kym Horsell <kym@kymhorsell.com> - 2016-02-05 22:31 +0000
                Re: Moon was produced by head-on collision? Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2016-02-05 22:50 +0000
                Re: Moon was produced by head-on collision? willner@cfa.harvard.edu (Steve Willner) - 2016-02-11 19:44 +0000
                Re: Moon was produced by head-on collision? Sam Wormley <swormley1@gmail.com> - 2016-02-06 12:41 -0600
                Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-06 01:20 -0800
                Re: Moon was produced by head-on collision? moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-02-06 18:37 +0000
                Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-06 12:53 -0800
                Re: Moon was produced by head-on collision? moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-02-07 01:28 +0000
                Re: Moon was produced by head-on collision? dlzc <dlzc1@cox.net> - 2016-02-07 07:06 -0800
                Re: Moon was produced by head-on collision? moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-02-08 02:58 +0000
                Re: Moon was produced by head-on collision? dlzc <dlzc1@cox.net> - 2016-02-08 06:35 -0800
                Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-07 13:54 -0800
                Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-07 15:11 -0800
                Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-07 16:16 -0800
                Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-08 21:36 -0800
                Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-09 11:37 -0800
            Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-04 12:39 -0800
      Re: Moon was produced by head-on collision? willner@cfa.harvard.edu (Steve Willner) - 2016-02-03 22:16 +0000
        Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-03 22:22 -0800
          Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-03 22:38 -0800
            Re: Moon was produced by head-on collision? The Starmaker <starmaker@ix.netcom.com> - 2016-02-04 11:46 -0800
              Re: Moon was produced by head-on collision? the_shadow <the_shadow@xcoxx.net> - 2016-02-06 07:30 +0000
          Re: Moon was produced by head-on collision? dlzc <dlzc1@cox.net> - 2016-02-04 07:52 -0800

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