Absence of Correlation Between Lunar Phases and Birth Rates: A Statistical Analysis of 135,000 Japanese Individuals

Takeshi Minakawa* Charapla Inc., Yokohama, Japan
*Correspondence: [info-www.charapla.net]
November 24, 2025
[日本語]

Permanent Archive (Internet Archive)
https://osf.io/fy8zp/files/ywv7k

Abstract

AbstractBackground: The belief that the frequency of births increases during the full moon or new moon (the so-called “lunar effect”) persists among the general public and some medical professionals, despite a lack of established medical evidence. Objective: The purpose of this study is to verify whether lunar phases have a statistical influence on birth rates using a large-scale dataset of over 100,000 Japanese individuals. Methods: We analyzed birth data from 135,748 individuals collected via the entertainment web service “charapla.net” between 2010 and 2017. The lunar age (0–29) at birth was calculated for each individual. Expected frequencies were derived from a calendar-based simulation to account for the variation in the duration of lunar phase categories. The goodness-of-fit was analyzed using the Chi-square test and Cohen’s w for effect size. Results: The distribution of births across lunar ages was extremely flat. No specific increase in births was observed around the full moon or new moon. Although a statistically significant difference was detected (χ2(29) = 55.43, p = 0.0022), the effect size was negligible (Cohen’s w = 0.02). Conclusion: The results statistically demonstrate that there is no substantial association between lunar phases and birth rates in the contemporary Japanese population.
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The Valley of the Mean : Are We Judging Planets Against a Line They Rarely Occupy?

[日本語]

1. The Hook

Frequency distribution of Mars’ geocentric speed over 6,000 years (3000 BC – AD 3000). The blue dotted line indicates the “Mean Daily Motion.”

Before we exchange any words, I would like you to simply look at this blue dotted line. This visualization represents the daily speed of Mars over a span of 6,000 years, from 3000 BC to AD 3000, based on data from NASA’s Jet Propulsion Laboratory (JPL).

The blue line marks the “Mean Daily Motion of Mars”—approximately 0°31′. For millennia, we have trusted this value as the “Standard,” using it as the definitive yardstick to judge whether a planet is “Swift” or “Slow.”

However, the reality this graph reveals is a landscape quite different from our conventional wisdom. Look closely. In the immediate vicinity of the blue line we call the “Standard,” Mars does not linger nearly as often.
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Redefining Mercury’s Apparent Ecliptic Speed

Redefining Mercury’s Apparent Ecliptic Speed Using 200 Years of Empirical Astronomical Data (1900–2100)

Author

MINAKAWA Takeshi
Astrogrammar Research, Charapla Inc,
Yokohama, Japan
November 17th, 2025
[日本語版]

Abstract

Traditional astrological classifications of Mercury’s apparent daily speed—Slow, Average, and Fast—have historically been determined by conventional intuition rather than empirical astronomy. This study calculates 73,213 days of Mercury’s geocentric apparent ecliptic longitude speed from 1900 to 2100 using the JPL DE440s ephemeris and the Skyfield computation library. The resulting distribution reveals statistically robust boundaries based on quartiles and physically meaningful structures related to Mercury’s orbital dynamics. We propose a new five-tier classification—Ultra-slow, Slow, Average, Fast, Very-fast—which integrates statistical percentiles and dynamical constraints near retrograde stations. This framework represents fully empirical and reproducible standard for Mercury’s speed in both astronomical and astrological contexts.
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Astrological Conditions for Success

Astrological Conditions for Success: Saturn and Mars

Twenty-five years ago, I was asked about the astrological conditions for success. I remember explaining it at the time in terms of “Jupiter is…” or “Venus is…”. If I were asked the same question today, I would answer this way.

The first condition for success is “to fail.” The second is “to not quit.” The third is “to decide for yourself what success means.”

These may sound different from the glittering laws of success. They might even suggest a gritty, unglamorous path. But as we overlap the astrological planets with our own lives, these three conditions should become clearer.

Contents The Effectiveness of Failure The Passion That Supports “Not Quitting” You Define Success Getting Lost on Your Own Path with Someone Else’s Map Strategic Use of Natural Significators Failure as Normal Operation — The Work of Saturn and Mars The Two Pillars Supporting Continuation — Saturn’s Patience and the Sun’s Will Defining Your Own Success — A Team Effort Philosophy and Operation, and “When Things Just Won’t Work” Practical Work for Using the Stars as a Compass
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