Every fall provides a special excuse for all thinking people to celebrate recreational math, magic and rationality, some of the things that were dear to America’s greatest man of letters and numbers, former Scientific American columnist Martin Gardner (1914 ­– 2010), via Celebration of Mind events. While Gardner was without doubt the best friend mathematics ever had—and it’s said that his column reached a million readers a month at his peak—his career also saw him rub shoulders with Salvador Dali, the Amazing Randi, David Blaine, Teller (from the duo Penn & Teller), and two writers he influenced: Isaac Asimov and Vladimir Nabokov. I had the good fortune to get to know him for the last decade of his life, and he was a paragon of modesty, while remaining an intellectual powerhouse well into his nineties.

Celebrations of Mind have been held worldwide since 2010 on and around Gardner’s birthday (October 21), and are open to anyone to attend or organize. This year, there are several scheduled for the coming weeks, and it’s not too late to plan more. They range from impromptu do-it-yourself get-togethers to more structured activities or lectures; teachers in particular are encouraged to engage their students with some of the available resources. Children may enjoy Martin’s “Curious Speller” (pdf) The first time I met Martin, he got my attention immediately by showing me a tall thin glass and asking me if I thought its height exceeded its circumference.

Of course I fell for it and assured him that it did. He then took a ribbon of paper and showed me how wrong I was. In hindsight, since a cylinder’s circumference is pi times its diameter, it seems that our shaky grasp of girth is related to our failure to remember that pi is greater than 3 (never mind remembering any of its decimals).

A Celebration of Mind could start with that bar bet, or a playful Dollar Bill Geometric Vanish demonstration, or a Mobius Strip Surprise, or by pondering one of Gardner’s favorite questions: why does a mirror reverse left and right but not up and down? (Consideration of conundrums like the last one lead to one of his best known and most profound works, The Ambidextrous Universe.) Or one could watch one of Khan Academy’s Vi Hart’s series of hexaflexagon videos on YouTube, which went viral in October 2012, one of them rapidly attracting over 5 million views. Those videos were inspired by the first of the legendary 300 “Mathematical Games” columns that Gardner wrote for Scientific American from the mid 1950s to early 1980s. Hart, like Gardner before her, displays a rare touch and ability to connect with a wide audience, in her case via a more youngster-friendly medium. Some of Gardner’s most famous Scientific American columns are linked from here.

The posthumous Undiluted Hocus-Pocus—The Autobiography of Martin Gardner (Princeton), has just hit the streets (an appreciation appears in the October 2013 Scientific American), and it serves to remind us that the Scientific American columns and the numerous books those spawned only represent one facet of a man whose Amazon page currently lists 90 titles. On the cover, John H. Conway, whose “Game of Life” was the basis for a landmark October 1970 column, says, “Martin Gardner was the most learned man I have ever met. [H]e didn’t even get quantum mechanics wrong!” It’s more a memoir than an autobiography, and a recurring theme is his beliefs. Contrary to what a lot of his fans assume, he was neither atheist nor agnostic; in his later years he identified himself as a Mysterian. Chronological excerpts from this book—and additional Gardnerian tip-offs—are being tweeted daily at @WWMGT (What Would Martin Gardner Tweet?).

The last time I spoke to Gardner, he told me he’d just had a visit from Richard Dawkins. It would be fascinating to know exactly what they discussed—alas it’s not covered in this volume. Another surprising omission is M.C. Escher, whom he also knew, and whose geometric art landed on the cover of Scientific American in 1961 thanks to Gardner. Benoit Mandelbrot, whose beautiful fractal images he brought to the public’s attention via his column in 1979, only gets a brief mention.

Ironically, despite his fame in mathematical and scientific circles, Gardner’s only college degree was in philosophy (University of Chicago, 1936); he famously claimed never to have taken a mathematics class past high school, and viewed himself strictly as a journalist. Nevertheless, as ace magician and Stanford statistician Persi Diaconis has remarked, Gardner “turned dozens of innocent youngsters into math professors and thousands of mathematicians into innocent youngsters”—and he should know, having first met him in magic circles at the age of 13. Brainteasers that Gardner popularized for the space-race generation found their way onto NPR in more recent decades as some of Car Talk's opening Puzzlers.

Magic was one of Gardner’s first loves, and he more than made his mark in that arena—as an inventor and writer, not a performer—being named one of the 100 most influential magicians of the 20th century by MAGIC magazine in 1999. His proudest original magic creation was his Wink Change (published January 1971 in the Hierophant, No. 5). Curiously, his best seller was his Annotated Alice in Wonderland, which sold half a million copies over the last 50 years. He considered his volumes on philosophy and theology to be his crowning achievements, and two of his last books were on wordplay and G. K. Chesterton, respectively.

How does one keep up that level of productivity in so many arenas for so long? For starters, Gardner largely avoided TV, computers and email. At the National Museum of Mathematics in Manhattan recently, as part of an evening panel discussion called “Who Is Martin Gardner?” his son Jim revealed that his father never used a word processor, preferring his old-school mastery of typewriter, paper, scissors and rubber cement. He worked at home, mornings, afternoons and evenings, usually seven days a week, juggling huge amounts of reading, annotating, filing, corresponding and writing. Though he liked calculator math tricks, he balanced his checkbook with an abacus.

The photo on the right shows the famous lectern at which Gardner composed a lot of his work throughout his life. James Randi now proudly looks after it. “Each morning as I make my way to my office, I touch that desk and bid Martin good-morning,” he remarked to me wistfully a few months ago, adding, “Above my office desk is a photo of Martin sitting on the Alice-in-Wonderland statue in New York's Central Park. He looks down on me as I write this. No, he's never far from my memory and though he took consolation and comfort from entertaining a theist attitude, I'm still an atheist. If Martin was thus comforted, I was similarly satisfied.”

In person, Gardner was a shy and unassuming man who kept a healthy distance from the fame he had acquired, preferring to keep on writing quietly rather than rest on his laurels. Somewhat fittingly, his last published article during his lifetime was written at the age of 95 for Skeptical Inquirer, a magazine he'd helped to found in the 1970s. It was called “Oprah Winfrey: Bright but Gullible Billionaire” and focused on questionable medical information she often featured on her show. It was fitting because his first book was the early 1950s classic Fads and Fallacies in the Name of Science (Dover). He was, first and last, a debunker, and nothing irked him more than pseudoscience. It’s little wonder that Stephen Jay Gould called him our "single brightest beacon” for the defense of rationality and good science against mysticism and anti-intellectualism.