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Insomnia during full moon?

  1. Jun 4, 2012 #1
    First of all, I'm rather new to this forum and I didn't know where to put this thread, but I think General Discussion will do.
    Just recently I've been talking with my friend about how we can't sleep when the Moon is in its full stage, and I think some of you might also have this "problem".
    The point is, we were trying to figure out why is that the case. My friend tried to came up with some paranormal activities and so on, while I was trying to figure some scientific way to prove it. The only thing I could came up with so far was that the Moon was a bit closer to the Earth while in full stage (honestly, I don't know if that's the case) and that screwed up a little with humans brain, or that the amount of light reflected by the Moon was larger than at any other phase, and that also made some impact on our brains.
    The question is (regardless if any of the above are correct) why this insomnia effect is not the case with all the people (or none).

  2. jcsd
  3. Jun 4, 2012 #2
    Do you have any scientific evidence that this is a common, widespread problem??

    If it is not a common problem (which I suspect), then there might be easy explanation for this fact:

    1) Your friend realizes that its full moon and so expects he will not be able to sleep well. This leads to him not sleeping well. A bit like a placebo effect.

    2) There might also be a confirmation bias. If your friend doesn't sleep well when it's not during full moon, he might forget about it. But when it's full moon, he suddenly thinks it's the full moon causing it.
  4. Jun 4, 2012 #3
    The moon reflects more light when it's full, so it's brighter out at night. Being exposed to light at night can inhibit the production of melatonin which is a factor in the sleep/wake cycle.

    That said, the effect of the brightness of the full moon would likely be small and completely drowned out by modern life (and the light bulbs that come with it). So, micromass's explanation is probably the best one (it's the one that explains most "full moon" phenomena).
  5. Jun 4, 2012 #4
    I have a terrible time sleeping during the full moon but I don't buy the paranormal stuff about it making people agitated and crazy. It's just harder to relax thinking about all the werewolves out there.
  6. Jun 4, 2012 #5


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    I definitely have a hard time sleeping because of the light. I wake up, noticed how bright it is, and think it's just about dawn and I should be getting up soon.
  7. Jun 4, 2012 #6


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    There is too little information to be offering much in the way of helpful ideas. For example, several people have mentioned how much brighter it is during a full moon, yet the OP makes no mention of the lighting conditions when trying to sleep. If his room is dark, all of this is moot.

    What we have to do is seek information to rule out factors.

    Personally, I think even before that we'd have to rule out observational bias.

    There is a popular wive's tale among nurses that more babies are born during a full moon than any other time.

    There are several problem with this:

    1] How long does a full moon last? one night? Or 3-5 nights? 3-5 nights is about 1/8 to 1/6 of a cycle, not 1/27th of a cycle. So, just how many babies is over that time period is "more"?

    2] How many nurses, upon a baby being born, look out the window and make a note in their observations that this baby was astonishingly born during the Moon's waxing gibbous? They don't. Full moons are highly memorable. Anything else is not.

    Same things apply to your situation. Have you done an objective measurement? Or did you just experience insomnia, then look up out your window and see a full moon?
  8. Jun 4, 2012 #7


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    There's lots of full moon myths; one of my favorite (since I believed it for so long after being told by a cop in my youth; hey, they're the authorities!):


    The only mechanism I can think of that would cause insomnia under a full moon, is the bright light. Light does act on circadian rhythms... but is the moon's light significant enough to affect melatonin/cortisol levels like the sun does? Melatonin requires UV-sized wavelengths, while cortisol levels can be affected by even green-size wavelengths[1], so maybe cortisol-linked sleep/wake behaviors would be affected, which might cause insomnia in a small percentage of the population. But this is just a hypothesis. In most cases, a consistent sleeping schedule should dominate light influences (in Alaska, we do have cases of seasonal affective disorder from the light not having a stable year-long cycle, in which case some affected people have to dawn "happy lights" to use regularly for an hour a day).

    [1] Steven W. Lockley, PhD1,2; Erin E. Evans, BS, RPSGT1; Frank A.J.L. Scheer, PhD1,2; George C. Brainard, PhD3; Charles A. Czeisler, PhD, MD1,2; Daniel Aeschbach, PhD. Short-Wavelength Sensitivity for the Direct Effects of Light on Alertness, Vigilance, and the Waking Electroencephalogram in Humans. SLEEP, Vol. 29, No. 2, 2006.

  9. Jun 4, 2012 #8


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    Methinks you have not read my post above.
  10. Jun 5, 2012 #9
    Okay, first of all I don't know if it is very common problem or just some people I know tend to have it, but certainly it's not a little one.
    As for the werewolves, thumb up for you mister.
    About the lighting, my room is exposed to the moons light most of the night, but my friends room is rather dark, and yet we both have the same problem. Maybe we subconsciously "feel", that the night is brighter.
    And sometimes I just can't sleep and then walk up to the window and realize it's a full moon, sometimes I know it in advance (and that might be me acting upon my psyche). I remember when long time ago my mom told me (after me having sleepless night) that she also had trouble sleeping when the Moon was full, since then I started paying more attention to it, so it all might be in my head. Don't know if that's the case with other people however.

    And thanks for so much replies so quick.
  11. Jun 5, 2012 #10
    By coincidence I happened to run across this passage in an old novel from 1872 I started reading online:

    J. Sheridan Le Fanu
  12. Jun 5, 2012 #11
    I don't think it's a bad first step to ask yourself "is there even a possible mechanism by which this could be plausible?" That's how superstitions and astrology and *most* "full moon effects" can be quickly dismissed.

    In this specific case, there is a mechanism by which the full moon could have an effect on sleeping, so I cannot just dismiss it out of hand. Since I cannot do that, THEN I start looking to rule out things, and consider observational bias, as you say.

    Everybody uses the tools in their skepticism toolbox differently, I guess. As long as they're being used, that's what's important.
  13. Jun 5, 2012 #12


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    I have insomnia most nights, but I get moody during full moon and can easily get angry.
  14. Jun 5, 2012 #13

    Chi Meson

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    I have rejected all things unorthodoxically paranormal since the age of 15, and have rejected all orthodox paranormalities since then.

    Still I had the sleepless full-moon problem. I have since attributed it to a combination of all three effects mentioned so far: placebo ( I notice it is a full moon, and therefore I know I won't sleep well, and therefore I don't), confirmation bias (Chance of not sleeping well is just as likely any other point in lunar cycle), and fear of werewolves (they are just so darn scary!).
  15. Jun 6, 2012 #14


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    Hello bajsi,

    Welcome to Physics Forums!
    It is not the case. The Moon does have an elliptical orbit, with an apogee when the Moon is farther from the earth and a perigee when it is closer. But the apogee and perigee of the Moon are essentially unrelated to the Moon phase. Both are periodic, but they are not in sync.

    The Moon's orbital period around the Earth is about 27.3 days (its sidereal period, say from one perigee to the next [ignoring any processional effects]). But since the Earth-Moon system is also in orbit around the Sun, when the Moon completes one orbit, its phase is slightly different than it was at the beginning of the orbit, and it needs to move a little more before the phase cycle starts over. So the Moon's phase period is about 29.5 days (its synodic period).

    Occasionally the Moon's perigee lines up with it being full, such as happened around the beginning of last month (~May 5, 2012). But for most full Moons, they're not lined up.
    That is correct. Not only is the moon brighter when it is in its full phase, it is a lot brighter.

    Moon dust is fairly retro-reflective. That means it tends to reflect light back towards the light source, instead of scattering the light in diffuse, random directions. It's the same effect that you can observe on road signs at night, or dewy grass in the morning (See Heiligenschein http://en.wikipedia.org/wiki/Heiligenschein or Opposition Surge http://en.wikipedia.org/wiki/Opposition_effect.) Since the light striking the Moon originally comes from the Sun, and since during a full Moon the Earth is more-or-less in between the Moon and the Sun, much of that extra "Opposition Surge" light is reflected back toward Earth.

    The end effect is the moon is significantly brighter when full compared to what one might expect with a diffuse reflector (for example, the moon is significantly brighter at full than twice as bright at first quarter).

    You might try closing your window blinds.
    :rofl: :eek: :yuck: ... I just choked on a handful of peanuts.
    Last edited: Jun 6, 2012
  16. Jun 6, 2012 #15
    Interesting, but I'm not that ambitious. My goal is merely to get someone to spew out a drink and destroy their computer.
  17. Jun 14, 2012 #16
    I am also affected by insomnia during the night before, the night of, and the night after a full moon. I am 79 years old and have had this problem for over 50 years. The strange thing is that on those nights I am not the least bit sleepy--wide awake and alert. It took me about 30 years to realize that it was connected to the full moon. I finally connected that I didn't need to turn on lights when I was wandering around. As background, I am by nature a "night owl", perfectionist tendencies, typical class "A" personality, heart attack at 40. I now accept it as just one of those strange oddities that all humans possess and realize that every month I will have 3 sleepless nights. For many years I slept in a completely dark room and couldn't tell if it was light. Now have night lights in every room so it is never completely dark--full moon or not.
  18. Jun 14, 2012 #17


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    Odd, I find the full moon relaxing. I love watching the full moon rise when I'm falling asleep.

    I can't sleep in complete darkness, I either have nightlights or if I'm traveling, I'll leave the bathroom light or closet light on in hotel rooms or homes I'm visiting and leave the door cracked open if I forget to pack a nightlight.
  19. Jul 26, 2013 #18
    I just read something about this in a health forum, where a study was done with 65 subjects, indicating that during a full moon, subjects took longer to fall asleep, slept a shorter duration, and not as deeply. One person suggested it might be an evolutionary leftover....when it was not safe to sleep deeply during a full moon, making a person an easy-to-spot target for predators.

    I too don't sleep well for 3 days around a full moon, and have been studying this for years and years (I'm 66 now, have had time to notice....)
  20. Jul 26, 2013 #19


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    Its probably just the increased light associated with a full moon. Its also possible psychological. There's really nothing else it could be.
  21. Jul 26, 2013 #20
    Any amateur astronomer can tell you how bright the full moon is at night. I've been woken up several times by my recollection while sleeping with a southward facing window by the light of the moon shining through my curtains.

    Other than that, there's no reason the full moon would have any influence on you. You probably wake up regularly, regardless of the phase of the moon, but you only remember the full moon because of how striking and bright it is. The other times you just fall back asleep.

    If you want to test this, sleep in a room with a window that faces north, or block all light from coming through your window.
  22. Jul 26, 2013 #21
    What! How early do you go to sleep? The full moon begins rising as the sun is setting!
  23. Jul 26, 2013 #22


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    not up North!
  24. Jul 26, 2013 #23
  25. Jul 26, 2013 #24


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    Interesting. Though one should note that it was published July 25, 2013 (yesterday) with the disclaimer: "there is a great deal of folklore but no consistent association of moon cycles with human physiology and behavior". 64 trial days and 33 volunteers - not the worse statistics.

    That's another plausible mechanism (an internal molecular clock). I don't really know how those are kept in tune (or if they need to be).

    Just as long as people don't start saying it's gravitational pulls on the brain, then I'll be ok.
  26. Jul 26, 2013 #25
    Sorry it is 20 min less, not 20% !!!
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