A biorhythm (from Greek βίος - bios, "life" and ῥυθμός - rhuthmos, "any regular recurring motion, rhythm") is an attempt to predict various aspects of a person's life through simple mathematical cycles. Most scientists believe that the idea has no more predictive power than chance and consider the concept an example of pseudoscience.

According to the theory of biorhythms, a person's life is influenced by rhythmic biological cycles that affect his or her ability in various domains, such as mental, physical and emotional activity. These cycles begin at birth and oscillate in a steady (sine wave) fashion throughout life, and by modeling them mathematically, it is suggested that a person's level of ability in each of these domains can be predicted from day to day. The theory is built on the idea that the biofeedback chemical and hormonal secretion functions within the body could show a sinusoidal behavior over time.

 Understanding the Three Cycles of Biorhythm Models 

Introduction to Biorhythm Models

 

Biorhythm models are fascinating tools that aim to explain the natural cycles that influence our physical, emotional, and intellectual states. These models typically incorporate three primary cycles: a 23-day physical cycle, a 28-day emotional cycle, and a 33-day intellectual cycle. Each cycle operates in a sinusoidal pattern, fluctuating between high and low extremes over set periods.

 

Details of Each Cycle

 

The 23-day physical cycle is believed to affect one's physical energy, stamina, and overall strength. During the high phase, individuals might experience peak physical performance, while the low phase could bring about fatigue and a decrease in physical capabilities.

 

The 28-day emotional cycle influences emotions, mood, and overall psychological state. Despite sharing the same duration as the average menstrual cycle, the emotional cycle and the menstrual cycle do not necessarily align. During the high phase, individuals may feel more emotionally stable and positive, whereas, during the low phase, they could experience mood swings and emotional turbulence.

 

The 33-day intellectual cycle affects cognitive abilities, such as logical reasoning, problem-solving skills, and memory. High phases in this cycle might enhance mental performance, while low phases could contribute to decreased cognitive functions.

 

Understanding Critical Days

 

Within each cycle, there are days known as "critical days" when the cycle crosses the zero line, transitioning from a high to a low phase or vice versa. These critical days are believed to carry a higher risk of incidents or unpredictability. It is during these transitions that individuals might need to exercise extra caution, as their physical, emotional, or intellectual states are in flux.

 

Conclusion

 

While biorhythm models provide an intriguing lens through which to view human performance and well-being, it is essential to approach them with a balanced understanding. The relationship between these cycles and everyday experiences can offer insights, but should not be seen as definitive predictors of one's abilities or emotions.

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In addition to the three popular cycles, various other cycles have been proposed, based on linear combination of the three, or on longer or shorter rhythms.

Calculation

The equations for the cycles are:

• Physical: sin(2π t/23)
• Emotional: sin(2π t/28)
• Intellectual: sin(2π t/33)

Where t indicates the number of days since birth.

Basic arithmetic shows that the simpler 23- and 28-day cycles repeats every 644 days (or 1-3/4 years), while the triple 23-, 28-, and 33-day cycles repeats every 21,252 days (or 58.2+ years).

History

The notion of periodic cycles in human fortunes is ancient; for instance, it is found in natal astrology and in folk beliefs about "lucky days". The 23- and 28-day rhythms used by biorhythmists, however, were first devised in the late 19th century by Wilhelm Fliess, a Berlin physician and patient of Sigmund Freud. Fliess believed that he observed regularities at 23- and 28-day intervals in a number of phenomena, including births and deaths. He labeled the 23-day rhythm "male" and the 28-day rhythm "female", matching the menstrual cycle.

In 1904, psychology professor Hermann Swoboda claimed to have independently discovered the same cycles. Later, Alfred Teltscher, professor of engineering at the University of Innsbruck, came to the conclusion that his students' good and bad days followed a rhythmic pattern of 33 days. Teltscher believed that the brain's ability to absorb, mental ability, and alertness ran in 33-day cycles. One of the first academic researchers of biorhythms was also Estonian-born Nikolai Pärna, who published a book in German called Rhythm, Life and Creation in 1923.

The practice of consulting biorhythms was popularized in the 1970s by a series of books by Bernard Gittelson, including Biorhythm — A Personal Science, Biorhythm Charts of the Famous and Infamous, and Biorhythm Sports Forecasting. Gittelson's company, Biorhythm Computers, Inc., made a business selling personal biorhythm charts and calculators, but his ability to predict sporting events was not substantiated.

Charting biorhythms for personal use was popular in the United States during the 1970s; many places (especially video arcades and amusement areas) had a biorhythm machine that provided charts upon entry of date of birth. Biorhythm charts were common in newspapers, usually found with horoscopes, at the time as well. Biorhythm programs were a common application on personal computers; and in the late 1970s, there were also handheld biorhythm calculators on the market, the Kosmos 1 and the Casio Biolator. Though biorhythms have declined in popularity, there are numerous websites on the Internet that offer free biorhythm readings. In addition, there exist free and proprietary software programs that offer more advanced charting and analysis capabilities.