✦ The science behind… · by Wooly the scientist
The Moon & You
What it really affects — and what it honestly doesn't.
The Moon is the most romantic object in the sky, and we've credited it with everything from madness to menstruation. Some of it is beautifully real. Some of it is myth. Let's sort the two — what the Moon genuinely does to you, and what it only seems to.
The Moon truly moves the oceans
Tides are real, and they're the Moon's (and Sun's) gravity in action — a well-understood, daily, planetary-scale effect. That part is pure, proven physics.
But “you're 60% water, so the Moon pulls on your body like the tides” is a myth. The Moon's tidal force on something as small as a body is vanishingly tiny — a wall next to you exerts more gravitational pull than the Moon's tidal difference across you.
The tides are still a gorgeous, daily reminder that we live on a rock in space, dancing with another one. Wonder, honestly earned.
Full moon, sleep and behaviour
One careful study (Cajochen, 2013) found people slept a little worse around the full moon under controlled conditions — small, intriguing, not always replicated. Before electric light, a bright full moon plausibly did disturb sleep.
But the big cultural belief — full moon = more ER visits, crime, births, “lunacy” — has been studied exhaustively, and a large meta-analysis (Rotton & Kelly, 1985) found no reliable effect. The word “lunatic” is folklore, not data.
Tracking the Moon can still be a gentle monthly rhythm for reflection — a built-in reminder to pause and check in.
Menstrual cycles and the Moon
The cycle and the lunar month are both roughly 29 days, which is why the link feels ancient and intuitive.
But large studies of real cycle data (e.g. Helfrich-Förster, 2021) find only weak, intermittent alignment — cycles don't reliably track the Moon. The matching length is mostly coincidence.
Syncing your journaling or self-care to the Moon is a lovely ritual — its power is the rhythm and intention, not a gravitational tug.
What the Moon really gives you
A calendar older than any clock, a monthly rhythm humans have organised life around for millennia, and one of the easiest doorways to awe — that wellbeing-boosting feeling of smallness before something vast.
You don't need the Moon to control your body for it to be meaningful. A shared rhythm and a nightly invitation to look up is plenty of magic.
Real, without the myth
The Moon doesn't tug your moods or your blood — but it does pull the seas, mark time, and pull your gaze upward. That's real, and it's enough. Keep the ritual, drop the myth, and let the honest Moon still feel like magic. ✦
Sources
- Christian Cajochen et al., « Evidence that the lunar cycle influences human sleep », Current Biology (2013) — léger effet sur le sommeil en conditions contrôlées.
- Rotton & Kelly, « Much ado about the full moon: A meta-analysis of lunar-lunacy research », Psychological Bulletin (1985) — aucun effet fiable sur le comportement, les urgences, les naissances.
- Helfrich-Förster et al. (2021) — synchronisation seulement faible et intermittente entre cycle menstruel et phases lunaires.
- NOAA / NASA — les marées, effet gravitationnel réel de la Lune et du Soleil ; la force de marée sur un corps humain est négligeable.
- Dacher Keltner & collègues — recherches sur l’« awe » (émerveillement) et le bien-être.
A documentary article, for reflection. It reports established science and clearly names what is belief or interpretation.