Seeking explanation of odd lunar phenomena

January 1, 2008 7:13 AM

Can the Moon affect humans in specific ways?

Is there any evidence that the rhythms of the Moon have an effect on anything smaller than the tides? I'm reasonably well-versed in astronomy and physics, and have been taught that the Moon exerts enough force on the Earth to control the tides, but not much more. Additionally, I'm an atheist, so I don't harbor any beliefs about spirituality, but it really does seem as though the rhythms of the Moon affect my health and general outlook, best at the Full Moon, worst at the New Moon, even when I'm completely unaware of the phase. I even came down with a serious illness on the day of the last lunar eclipse. I'm desperately trying to find a scientific explanation for this, but I simply can't find anything substantial, apart from scientific papers on the synchronicity of women's menstrual cycles with lunar cycles, when I am in fact male. Does anyone have an idea?

posted by malusmoriendumest to science & nature (28 answers total)

My understanding is that there have been medical studies (both in human and veterinary medicine) done on emergency room visits during the full moon, and that the studies concluded that there are more visits during the full moon than would be expected otherwise. I'm afraid I don't have any kind of citation for you, but I'll do a little poking around to see if I can't find the journal articles. This seems to run counter to your experiences, though.

As far as an explanation, this is just a theory, but we have all sorts of psychological and behavioral holdouts from our less-civilized days (from choice of sexual partners to eating habits) and I wouldn't be surprised if this is another example.
posted by Rock Steady at 7:28 AM on January 1, 2008

Confirmation bias, that is, you notice two things which seem to happen together, though unrelated. When they don't happen together (proving that they're unrelated) you find it unremarkable and forget about it. Thus your mind convinces its self that they only happen together (as it has forgotten all of the other times).
posted by anaelith at 7:29 AM on January 1, 2008

...The Moon exerts enough force on the Earth to control the tides, but not much more.

I don't have any conclusive research for you, but the effect on the tides is actually quite dramatic, and I would think any body that exerts enough force to keep our oceans heaving so would pretty much HAVE to affect our sensitive, permeable bodies and minds. We are made mostly of water, you know.

*Shuts up, sits back and waits for science-y types to address the matter*
posted by hermitosis at 7:33 AM on January 1, 2008

Anecdotal: I worked as a late-shift 411/Directory Service operator and the full moon nights were plagued by more erratic and outright crazy calls than any other time of the month, both in volume and intensity. I had a habit of jotting down and saving phrases or details from weird calls and those evenings had more of those interactions, whether or not I was aware of the phase of the moon. My call times (we were continually monitored and pushed to manage more calls per shift and lower our times) were higher then, too, because it took longer to deal with those folks. Co-workers noticed the same phenomenon. My casual conversations with 911 dispatchers and ER staff correlate my thoroughly-unscientific theory.
posted by bonobo at 7:35 AM on January 1, 2008

Here's a shitload of data with references to studies, and the skepdic entry on full moon / lunar effects.
posted by Wolfdog at 7:48 AM on January 1, 2008 [2 favorites]

The short answer is no, there are no effects shown by any studies, despite what people who work in emergency departments may say (not that they are lying, they are mistaken). There is also nothing that could make you sick or susceptible to disease during a lunar eclipse.

A good overview, Car accident rates, attempted suicide, emergency room admissions .

"Misconceptions about such things as the moon's effect on tides have contributed to lunar mythology. Many people seem to think that since the moon affects the ocean's tides, it must be so powerful that it affects the human body as well. The lunar force is actually a very weak tidal force. A mother holding her child "will exert 12 million times as much tidal force on her child as the moon"
posted by tomble at 7:52 AM on January 1, 2008 [1 favorite]

"Misconceptions about such things as the moon's effect on tides have contributed to lunar mythology. Many people seem to think that since the moon affects the ocean's tides, it must be so powerful that it affects the human body as well. The lunar force is actually a very weak tidal force. A mother holding her child "will exert 12 million times as much tidal force on her child as the moon"

Exactly. The reason you see the effects on the ocean is that there's so much freakin' ocean.
posted by stevis23 at 8:08 AM on January 1, 2008

In short: the lunar effect (moon madness) cannot exist as a result of lunar gravity. If it existed as it is generally conceived, it would have to be caused by light, and you would have to believe that moonlight--and not sunlight or, in these days of pervasive electric light pollution, electric light, but moonlight alone--has some deleterious effect on people's minds. It's a lot like astrology. Of course it is supported by anecdotes such as bonobo's, but don't forget (as if people around here would let you) everyone's favorite phrase, confirmation bias.

Biorhythms are not based on the phases of the moon and have never been shown to correspond to any sort of reproducible dataset. Biorhythms are based on mumbo-jumbo.
posted by pracowity at 8:23 AM on January 1, 2008

Gravity affects all matter; not simply water.

It should be pointed out that the tidal effect exerted by the Moon (and the Sun) do not only affect water, but the entire planet. Some particle physics experiments at CERN have to take into account the change of shape of the Earth as it affects the shape of the accelerator (*not* located on water!). Since the water is freer to move than the soil, we can see the tidal pull better.

Furthermore, the tidal pull is towards the Moon (or Sun, depending on which one you want to consider). So, if you move slighly, the tidal distortion on your body is going to be in a different direction...

Anyway, for anyone who thinks that we should be affected by the tides *because* we are made mostly of water ... think again.
posted by aroberge at 8:25 AM on January 1, 2008 [2 favorites]

One word: Lunaception.
posted by thedanimal at 8:27 AM on January 1, 2008

More anecdotal evidence. My mother-in-law, who worked as a night nurse for over 20 years always said they had more people at the hospital during the full moon. My sister, who works with mentally challenged people says that her clients often go "on the rip" (episodes where they are acting out) during the full moon. Sometimes I'm convinced that things go screwy at my office during the full moon, but I'm probably just grasping for straws. But if people are legitimately affected (and I think they are), it could explain why things tend to get weird during that time.

Here is a link to a study done in 1980 connecting the lunar cycle's influence on menstrual cycles. (Published in the American Journal of Obstetrics and Gynecology.) There has been a connection between lunar and menstrual cycles for thousands of years - this is another interesting link.
posted by melissa at 8:41 AM on January 1, 2008

D'oh, looks like thedanimal beat me to the moon/menstruation connection!
posted by melissa at 8:44 AM on January 1, 2008

The most obvious way the moon would influence the behavior/feelings/mood/emotions/or whatever of humans (or other life forms) is by its light and the visible waxing and waning of its phases. Especially if you are a person (or other life form) that lives, works, sleeps, etc., outside, just the extra, rather bright, light out at night during the full moon, and then later the absence of that light, is really rather obvious and remarkable.

Also just the fact of the moon's being up there in the sky, easily visible as some sort of planet or somewhat earth-like object that seems to follow a regular path and pattern of waxing and waning, makes me feel pretty curious about what it is, how it got there, whether any type of beings live there or could live there, and all the rest. There is pretty good evidence that it (and the other heavenly bodies) have affected many millions of people the same way throughout history, afflicting them with terminal curiosity about "what is up there" and "how it works", leading to some rather substantial changes and advances in human knowledge, civilization, and even technology (Tang, anyone?).

So yeah, I'd submit that the moon does have a rather strong method of influencing human thought and behavior, other than by its gravitational influence, and that is via the strong and somewhat mysterious beams of electromagnetic radiation it sends streaming our way.

Whether those can make you have a headache or a car crash or whatever, is perhaps a somewhat different question . . . but they can certainly fill you with wonder and delight!
posted by flug at 8:57 AM on January 1, 2008 [4 favorites]

Here is an abstract of the recent veterinary medicine study I was thinking of. Looks like it is pretty well debunked as far as human medicine goes, though.
posted by Rock Steady at 9:00 AM on January 1, 2008 [1 favorite]

you would have to believe that moonlight--and not sunlight or, in these days of pervasive electric light pollution, electric light, but moonlight alone

Moonlight is sunlight.
posted by ROU_Xenophobe at 9:08 AM on January 1, 2008

Previously, with a link to Cecil Adams on the moon-menstruation link.
posted by mediareport at 9:10 AM on January 1, 2008

(In short, folks who are claiming a link between the moon and menstrual cycles have an obligation to explain what's so special about human and possum cycles that they're among the few in the animal kingdom that average around 28 days long. And thedanimal, that wikipedia page you linked is remarkably free of any science; I especially like the way it claims, "many studies have been done in 'real-life' situations where women have made every available attempt to control the amount of light, and some very convincing results have been observed" - without citing any studies.)
posted by mediareport at 9:24 AM on January 1, 2008

Just because there is no evidence does not mean it doesn't have an effect. It's like religion, astrology, and paper currency--there may be nothing backing it up, but if enough people believe in it, their behaviour changes, and that has a social effect. Confirmation bias has a social effect. Wars are fought with no evidence to back them up. Our whole social structure favors tribal alliances over truth.
posted by weapons-grade pandemonium at 9:38 AM on January 1, 2008

A full moon has always made it much more likely that I engage in a nighttime sporting activity such as nighthiking, nightclimbing, or mountainbiking for the simple practical reason that you can see better. Anecdotal, but it wouldn't surprise me at all if a study were find a correlation between humans simply being more active during a full moon than otherwise.
posted by Manjusri at 9:42 AM on January 1, 2008

their behaviour changes, and that has a social effect.

Of which there would be evidence.
posted by kiltedtaco at 10:13 AM on January 1, 2008 [1 favorite]

In rural areas the light of the full moon is remarkable. I think many people think that "moonshadow" is just a poetic phrase. It's not, and doubly so on or near the water and on snow. However, it must be seriously diffused as a potential causative effect in cities, where most of the anecdotal evidence comes from.
posted by Rumple at 10:44 AM on January 1, 2008

The sun takes 26 days to complete one rotation, because we are also in rotation with the sun one rotation relative to earth takes 28 days .The Sun is calling the tune, earth and moon follow the lead.
posted by hortense at 11:04 AM on January 1, 2008

"...their behaviour changes, and that has a social effect."

Of which there would be evidence.
posted by kiltedtaco at 10:13 AM

Sure, but the evidence may not coincide with the phases of the moon.
The conversation we're having right now is evidence of the full moon effect.
posted by weapons-grade pandemonium at 11:54 AM on January 1, 2008 [1 favorite]

Tomble, those folks in the ED aren't lying; they're referring to a study published several decades ago (my memory says 1987??) that claimed to show more ED visits during full moons. The study was recently (since 2000) attempted to be replicated on a much larger scale, and the findings were not borne out; there were more ED visits on Saturdays but moon phase did not appear to be an independent variable influencing number of ED visits. I'm sorry I can't reference these articles but my collection of curious and not useful articles is packed away at the moment.

The original study also claimed to show more trauma due to intentional violence during the full moon, and fewer car accidents; the reverse was seen during the new moon. The plausible and interesting explanation put forward for this was that people are more likely to attack other people when they are visible in the higher-light conditions of a full moon; they're less likely to crash their car, however, when they could see where they were going.

Again, these plausible hypotheses could not be replicated in subsequent, larger and better-conducted studies.
posted by ikkyu2 at 12:05 PM on January 1, 2008

In short, folks who are claiming a link between the moon and menstrual cycles have an obligation to explain what's so special about human and possum cycles that they're among the few in the animal kingdom that average around 28 days long.

As mediareport's remark implies, if human cycles are synced to the moon, it's not because of the moon's overwhelming power, it's probably due to some advantage that has accrued to having cycles synced to the moon, and the subsequent or concurrent evolution of a mechanism whereby such synchronization could take place.

For humans, I think the advantage could have been that syncing nocturnal activity to the phases of the moon means being better fed if seafood is part of your diet. When the moon is full, the low tide is exceptionally low because the tidal effects of the sun and moon are additive as a result of their close astronomical alignment, and this exposes food sources usually safely hidden from greedy hands beneath feet of ocean water, and providentially provides light to see to harvest them by. A tendency to a kind of nocturnal mania at the time of the full moon could have been very useful, perhaps. This dovetails nicely with Robin Morgan's ideas about human adaptation to watery environments and more recent anthropological work suggesting that littoral zones were the primary highway by which we made our way around the world after we left Africa, I think.

Light could have been the main source of the cues allowing synchronization to take place, I suppose, but conflicting signals from seasonal variations in day length and noise from cloud cover make light seem like kind of a poor candidate to me, even disregarding the enormous amount of noise contemporary artificial lighting represents. Direct perceptions of changes in gravitational fields are out because the energies of those are so very tiny. However, there is a corresponding tide to ocean tides in the fluid of the atmosphere, and these tides result in cyclical variations in barometric pressure; that's a pretty noisy signal too, but partly because of all the reports of people's weird responses to weather-driven high and low pressures, it's where I would look first for sensory mechanisms with the potential to synchronize us to the moon.
posted by jamjam at 12:06 PM on January 1, 2008 [1 favorite]

The sun takes 26 days to complete one rotation, because we are also in rotation with the sun one rotation relative to earth takes 28 days .The Sun is calling the tune, earth and moon follow the lead.

The sun rotates differentially, with a sidereal period of 25 days at the equator to 34 days at the poles. Viewed from the earth, that's from 27 to 37 days. Regardless, the rotation of the sun has nothing to do with the orbit of the moon.
posted by kiltedtaco at 12:41 PM on January 1, 2008 [1 favorite]

As someone who's in possession of a menstrual cycle (unfortunately) and to tag on to something that was said in the older thread... it's pretty easy to explain the lunar cycle lining up with someone's menstrual cycle as a misperception. Like sitting at a traffic light watching two turn signals blinking, they'll seem to blink together several times, then separately only a few times, then exactly opposite several times, and then separately only a few times. You would come to the conclusion that they're blinking either exactly together or exactly opposite more frequently than they're blinking in an unrelated manner, but really it's just your mind interpreting almost together as together, thus increasing the amount of time you perceive the two as being together.
posted by anaelith at 4:50 PM on January 1, 2008 [3 favorites]

Hmmm, this article says tides in the atmosphere are almost exclusively solar, very small, and caused mainly by heating. So much for that mechanism.
posted by jamjam at 3:29 PM on January 3, 2008