{"id":6943,"date":"2012-01-16T16:41:51","date_gmt":"2012-01-16T08:41:51","guid":{"rendered":"http:\/\/www.intmath.com\/blog\/?p=6943"},"modified":"2014-12-05T09:04:43","modified_gmt":"2014-12-05T01:04:43","slug":"biorhythm-graphs","status":"publish","type":"post","link":"https:\/\/www.intmath.com\/blog\/learn-math\/biorhythm-graphs-6943","title":{"rendered":"Biorhythm Graphs - background"},"content":{"rendered":"

I re-developed my Biorhythm Graphs<\/a> page (for various technical reasons). You can input anyone's birthday and you can see what their state will be (or was) on any day (well, that's the theory). <\/p>\n

Biorhythms are interesting, but not at all scientific. They are a quirky example of Composite Trigonometric Graphs<\/a>, since they involve 3 sine curves starting at (0,0) on your birthday, and having 3 different periods. <\/p>\n

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\"Biorhythm
\nBiorhythm cycles - starting from birth<\/p>\n<\/div>\n

They work on the principle that our bodies, minds and emotions go through various cycles throughout the month, leading us to have pre-determined "good days" and "not-so-good" days. I have assumed the "best" days (colored green on my graph) will be the days when all 3 cycles add to give us the largest amplitude, and the "worst" days (colored red) will be when all 3 cycles push us into the depths of despair. <\/p>\n

According to the Skeptik's Dictionary<\/a>, biorhythms were first "observed" by the Berlin physician Wilhelm Fliess (a good friend of psychologist Sigmund Freud's) in the 19th century. <\/p>\n

Fliess originally proposed a 23-day "male" cycle and a 28-day "female" cycle. An Austrian engineering teacher proposed a 33-day "mind" cycle, based on his observations of how well his students performed over time. <\/p>\n

They are now known as the physical<\/strong>, emotional<\/strong> and intellectual<\/strong> cycles. Apparently:<\/p>\n

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There is the 38-day intuitional cycle<\/em>, the 43-day aesthetic cycle<\/em>, and the 53-day spiritual cycle<\/em>.<\/p>\n<\/blockquote>\n

Head on over and put in your dates here:<\/p>\n

Biorhythm Graphs<\/a><\/p>\n

Math behind the graphs<\/h2>\n

Periods: <\/strong>To get graphs having wavelengths of 23, 28 and 33 days, I used these sine curves:<\/p>\n