# Moonlight effects - science vs. urban legends **URL:** \ **Category:** Factual Questions\ **Created:** [February 6, 2013, 6:49am UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464 "2013-02-06T06:49:39Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![komolono](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/komolono/32/532_2.png) [@komolono](https://boards.straightdope.com/u/komolono)\ **Post date:** [February 6, 2013, 6:49am UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/1 "2013-02-06T06:49:39Z")
At full moon I can not sleep. There’s some pressure in my veins - I feel it especially in my feet and it keeps me up all night. I’ve heard that there are a lot more “positive ions” in the air due to polarized light during full moon. What ions?H+? Well these positive ions react with hemoglobin in the red cells… How much of this is science or is just bull…t? What other things can REALLY happen at full moon? ---
**Author:** ![Floater](https://avatars.discourse-cdn.com/v4/letter/f/dc4da7/32.png) [@Floater](https://boards.straightdope.com/u/Floater)\ **Post date:** [February 6, 2013, 7:56am UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/2 "2013-02-06T07:56:39Z")
The part between “At” and “cells…” is pure bull. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [February 6, 2013, 12:36pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/3 "2013-02-06T12:36:32Z")
One thing that really can happen under moonlight, or indeed, any dim light (so not limited to full moon - sorry) is that our perception of colours becomes attenuated - everything tends to look blue, or monochrome. It’s called the [Purkinje Effect](http://en.wikipedia.org/wiki/Purkinje_effect) ---
**Author:** ![Octans](https://avatars.discourse-cdn.com/v4/letter/o/5f8ce5/32.png) [@Octans](https://boards.straightdope.com/u/Octans)\ **Post date:** [February 6, 2013, 1:04pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/4 "2013-02-06T13:04:47Z")
You must be absolutely crippled during the daytime (since moonlight is just reflected sunlight at a fraction of the intensity, after all). ---
**Author:** ![moriah](https://avatars.discourse-cdn.com/v4/letter/m/b2d939/32.png) [@moriah](https://boards.straightdope.com/u/moriah)\ **Post date:** [February 6, 2013, 1:05pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/5 "2013-02-06T13:05:51Z")
> [@komolono](#): > > At full moon I can not sleep. That could be because of moonlight because the light keeps you awake, so, draw the shades. Or, the anxiety of thinking that the moon is affecting you is keeping you awake. > [@](#): > > There’s some pressure in my veins - I feel it especially in my feet and it keeps me up all night. It can’t be because of the moon’s gravity. You don’t have enough mass to be affected like the tides of the oceans are. Also, when the moon is half full, it still gets to be overhead with the same amount of gravity, but this effect you feel is only at full moon… so, it’s not gravity. If you draw the shades, it’s not the light. More than likely, it’s anxiety from thinking the full moon is doing something to you. > [@](#): > > I’ve heard that there are a lot more “positive ions” in the air due to polarized light during full moon. What ions?H+? Well these positive ions react with hemoglobin in the red cells… Chaotically scattered dust on the moon will not create polarized light, it would just reflect scattered and non-polarized light. And if the earth’s atmosphere is polarizing the light, then it would do the same to the sun’s light, so, you have the same amount (or lack thereof) of polarizing light in the day and night. Does the quality of the air change at night? Yes. Caused by moonlight? No, from lack of sun. So, night air is night air whether the moon be full or not. > [@](#): > > How much of this is science or is just bull…t? What other things can REALLY happen at full moon? It’s bullshit. In a pre-industrial age, humans tend to go out at night during full moons because they can because of the full moon’s light. Then they scare themselves by being far out in the forest at night. That tends to make humans tell ghost stories that can only happen at the full moon. Werewolves and all that. During the new moon, people stay in their shelters and nothing interesting happens. There are not more accidents that happen at full moon. People aren’t more crazy (i.e., ‘lunacy’) during full moons. Women’s cycles, while they average the length of a lunar cycle, do not sync with the lunar cycle. Anxiety over what a full moon can do to you, as unsubstantiated as those beliefs may be, can have a real psychosomatic effect on you, though. ---
**Author:** ![Furious\_Marmot](https://avatars.discourse-cdn.com/v4/letter/f/dfb087/32.png) [@Furious\_Marmot](https://boards.straightdope.com/u/Furious_Marmot)\ **Post date:** [February 6, 2013, 2:14pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/6 "2013-02-06T14:14:59Z")
Even if there was a significant difference in the polarization of moonlight vs. sunlight, which there isn’t AFAIK, how would the amount of polarized light affect the amount of ions in the atmosphere? Can I slap a polarizer on a flashlight and get an ion beam? Because that would be so cool. ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [February 6, 2013, 2:21pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/7 "2013-02-06T14:21:44Z")
Maybe you’re suffering from a brain cloud? ---
**Author:** ![Dr.Drake](https://avatars.discourse-cdn.com/v4/letter/d/ad7895/32.png) [@Dr.Drake](https://boards.straightdope.com/u/Dr.Drake)\ **Post date:** [February 6, 2013, 2:27pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/8 "2013-02-06T14:27:19Z")
“Urban legend” is a specific type of narrative. It is not the same as “folklore,” “superstition,” “belief,” or “bullshit” any more than “evolution” is synonymous with “biology,” “science,” or “truth.” There is a lot of folklore specifically about the full moon (though no urban legends that I’m aware of) and its effect on the human body. None of it is scientifically verifiable. ---
**Author:** ![Sailboat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sailboat/32/461_2.png) [@Sailboat](https://boards.straightdope.com/u/Sailboat)\ **Post date:** [February 6, 2013, 4:18pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/9 "2013-02-06T16:18:56Z")
> [@Dr.Drake](#): > > There is a lot of folklore specifically about the full moon (though no urban legends that I’m aware of) Does “[Good Luck, Mr. Gorsky](http://www.snopes.com/quotes/mrgorsky.asp)” count? ---
**Author:** ![Dr.Drake](https://avatars.discourse-cdn.com/v4/letter/d/ad7895/32.png) [@Dr.Drake](https://boards.straightdope.com/u/Dr.Drake)\ **Post date:** [February 6, 2013, 4:34pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/10 "2013-02-06T16:34:48Z")
> [@Sailboat](#): > > Does “[Good Luck, Mr. Gorsky](http://www.snopes.com/quotes/mrgorsky.asp)” count? It’s not about the full moon. ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [February 6, 2013, 5:59pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/11 "2013-02-06T17:59:04Z")
I’d imagine that if polarized light had negative effects on people that LCD monitors wouldn’t be that popular, since a LCD display needs polarized light to operate. ---
**Author:** ![Laggard](https://avatars.discourse-cdn.com/v4/letter/l/9de053/32.png) [@Laggard](https://boards.straightdope.com/u/Laggard)\ **Post date:** [February 6, 2013, 6:16pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/12 "2013-02-06T18:16:43Z")
I’ve noticed it’s much harder to streak through your neighbors back yard without getting caught when it’s a full moon. ---
**Author:** ![gazpacho](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@gazpacho](https://boards.straightdope.com/u/gazpacho)\ **Post date:** [February 6, 2013, 6:19pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/13 "2013-02-06T18:19:51Z")
The idea that emergency rooms get more admissions during the full moon. Seems to me to be an urban legend and not folklore. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [February 6, 2013, 6:31pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/14 "2013-02-06T18:31:40Z")
> [@moriah](#): > > That could be because of moonlight because the light keeps you awake, so, draw the shades. Or do what I do. Close your eyes. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [February 6, 2013, 6:35pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/15 "2013-02-06T18:35:38Z")
> [@gazpacho](#): > > The idea that emergency rooms get more admissions during the full moon. Seems to me to be an urban legend and not folklore. Beat me to it. Although Urban Legends should have more of a narrative and twist at the end there’s been a lot of definition creep lately. Folklore is sometimes just old Urban Legend anyway. ---
**Author:** ![Dr.Drake](https://avatars.discourse-cdn.com/v4/letter/d/ad7895/32.png) [@Dr.Drake](https://boards.straightdope.com/u/Dr.Drake)\ **Post date:** [February 6, 2013, 8:13pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/16 "2013-02-06T20:13:59Z")
> [@TriPolar](#): > > Beat me to it. Although Urban Legends should have more of a narrative and twist at the end there’s been a lot of definition creep lately. Folklore is sometimes just old Urban Legend anyway. Urban legends are a type of folklore. Urban legends **must** have a narrative, otherwise they’re not narratives. A non-narrative expression of belief can be a rumour (if it’s alluding to a narrative) or a folk belief. ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [February 6, 2013, 8:24pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/17 "2013-02-06T20:24:07Z")
> [@Dr.Drake](#): > > . . . Urban legends **must** have a narrative, otherwise they’re not narratives. . . . Hmmm. . . ya don’t say. . . . ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [February 6, 2013, 9:31pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/18 "2013-02-06T21:31:53Z")
_When the moon hits your eye Like a big pizza pie, that’s amore_ ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [February 6, 2013, 10:04pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/19 "2013-02-06T22:04:38Z")
“Have you ever seen blood by moonlight? It appears quite black.” – Hannibal Lector ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [February 6, 2013, 10:45pm UTC](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464/20 "2013-02-06T22:45:06Z")
Moonlight from the full moon is not polarized (at least, the polarization is so close to zero that it’d be difficult to measure.) Light from a half moon might be slightly more polarized, since it’s scattered at an angle; I doubt it’s significant though. You know what _is_ strongly polarized? Blue sky during the day. Put on a pair of polarized sunglasses, look at blue sky and rotate your head; you’ll see a significant change in brightness. Also, **un** polarized light is just a mixture of all types of polarized light. If polarized light causes a certain chemical reaction, unpolarized light would cause it too. [Next page](https://boards.straightdope.com/t/moonlight-effects-science-vs-urban-legends/649464.md?page=2)