I asked him if the digits represented his social security number (don't laugh, I've heard it has been done) and he shook his head and rolled up his sleeve to reveal the top of the tattoo:
This, of course, is the value of π (pi), which mathematicians have determined, possesses an infinite number of decimal places.
As a physics enthusiast, he loves what pi represents. He told me, as the "meaning of symbols change a lot, what better [to have tattooed] than a transcendental constant?"
Despite π's infinite number of decimals, he only has the tattoo calculated out to 27 places because, he said, it was "all I could afford" at the time.
Later, Joe e-mailed me and gave me more specifics. The tattoo was done at Utopia in Huntington, New York (out on Long Island). I can't find a current listing foe the shop, so it may no longer be in business. And, Joe said, "the font is Times New Roman, the π symbol is 180pt font (π in degrees) and the numbers are 90pt font (π/2 in degrees)".
This careful selection of font size only emphasizes Joe's commitment to the purity of this πtattoo.
Thanks much to Joe for sharing this cool tattoo with us here on Tattoosday!