# Just Saying ...: Fibonacci Day

Tuesday, November 19, 2019 7:58 AM

*Contact the author by sending email to sadowski@tidewater.net. If you are writing about math, do it very slowly so that he can understand. © 2019, Tom Sadowski*
Have you got all your Fibonacci Day cards and gifts in order? I’m sure you remember that we are very close to Fibonacci Day, the celebration that fills the holiday void between Halloween and Thanksgiving. Every year it falls on November 23 or, as we customarily write the date: 11-23, which are the first four numbers in the Fibonacci series 1-1-2-3.

It’s a simple series of numbers where the next number is produced by adding the previous two numbers.

Every November 23 we celebrate that great Italian mathematician Leonardo Bonacci for whom the sequence is named. (Yes, this begs the question “why don’t we call it the Bonacci series?”) He lived in the Middle Ages about 800 years ago when they may not have had a lot of carefree fun but always took time for a little math.

Leonardo Bonacci used this sequence, which had been around and noted by Indian mathematicians way back in the sixth century, to address a rather trivial problem in his 1202 bestselling book “Liber Abaci” (not to be confused with the American pianist and entertainer Liberace). He may not have given it much thought because he was a busy guy thinking and doing bigger things.

Arguably, his most significant contribution was promoting the use of Hindu-Arabic numerals to replace the use of Roman numerals throughout Europe. In Roman numeral notation, it’s really hard to subtract I from L to get XLIX. It’s impossible to calculate percentage, interest or profits, so the Hindu-Arabic numeral notation that we use today (you know: 1 2 3 4 5 6 7 8 9) was gladly adopted by the business and banking communities in Europe.

The sequence apparently went with no name until the 1800s, when French number theorist Édouard Lucas saw their importance and started calling them Fibonacci numbers, a contraction of filo Bonacci, meaning the son of Bonaccio.

The application of the Fibonacci series is surprisingly useful and common in today’s sciences and math studies. There. That’s really about all I know of the Fibonacci numbers. It would be fabulous if I could take you on a journey exploring the wonders of the Fibonacci sequence, explaining how this mathematical series can be used to mirror all kinds of things that happen in nature, from the building of populations to the arrangement of spirals in flower heads and pinecones. I would go on regaling you with surprise relationships of Fibonacci numbers to the golden ratio and its application in art, architecture and financial markets.

Alas … (Now that’s a good word you hardly hear anymore; it embodies concepts like unfortunately, regrettably, disgracefully and sad-to-say. Few people use it in conversation but it’s quite perfect here.) Alas, I am not smart enough to do much more than fantasize about being smart. If you’re at all disappointed, think of how I must feel sitting here with all the other slow children who just don’t “get it.”

Being comfortable with math is like being fluent in another language. Each language allows you to see things as can be described by that language. A multilingual person sees the world through the lens of each language they understand.

I like to pretend that I understand math more than I actually do but I’m about as fluent in math as I am in Spanish. I can conjugate a verb or two, say deep-concept words like please, thank you, library and beer, and I know a couple of very handy phrases like “I’m sorry but my wife says no” and “Don’t shoot me, I am Canadian.”

This level of Spanish gives me almost no insight into how Spanish-speaking people think. Likewise, being a math ignoramus leaves me stranded on the shores of the sea of knowledge wading in only up to my knees; enough to know that it is deep, wide and out of reach without knowing the language.

So, are we going to explore why we as a nation are so bad at math? Surely there must be someone, a policy or organization onto which we can easily pin the blame. But that’s the trouble with truth: Just like math, it’s often complicated and blame is in many cases a complex web of coincidental failures.

We celebrate Fibonacci anyway and are thankful for those who can understand the numerical sequence that bears his name and productively apply it for everyone’s benefit. That’s civilization.

Historians are not sure but estimate that Fibonacci died between the years 1240 and 1250. I like to think it was the year 1235.