I can’t believe someone makes… Numerist clocks

Enough with the faceless watches, you say (passim here, here, and here)? Well, check out this wall clock instead. One for very special mathematicians.

No more 9 o’clock, but 21 ₍₄₎ o’clock. No more 6 o’clock, but 3! o’clock… See what we are doing here? Base 4 and factorials were never so much fun!

The crème de la calculation is ol’ midnight (or midday, as some know it): 3?1728.

Okay, whats quarter-past seven in numerist time? (see below for a full ‘cheat list’ for the hours).

Unusable, surely, but as with most items in this series, I’m glad someone does make this beauty! The Geek Clock will set you back $25 (there’s also a wrist watch version available – “It’s Half-Past a Binomial Coefficient”). Check out the video:

“Cheat Sheet”

12 – A radical
1 – Legendre’s constant is a mathematical constant occurring in a formula conjectured by Adrien-Marie Legendre to capture the asymptotic behavior of the prime-counting function. Its value is now known to be exactly 1.
2 – A joke in the math world: An infinite number of mathematicians walk into a bar. The first one orders a beer. The second orders half a beer. The third, a quarter of a beer. The bartender says, “You’re all idiots,” and pours two beers.
3 – A unicode character XML “numeric character reference.”
4 – Modular arithmetic, also known as clock arithmetic, is a system of arithmetic for integers, where numbers “wrap around” after they reach a certain value. The modular multiplicative inverse of 2 (mod 7) is the integer /a/ such that 2*/a/ is congruent to 1 modulo 7.
5 – The Golden Mean…reworked a little.
6 – Three factorial (3*2*1=6)
7 – A repeating decimal that is proven to be exactly equal to 7 with Cauchy’s Convergence Test.
8 – Graphical representation of binary code.
9 – An example of a base-4 number, which uses the digits 0, 1, 2 and 3 to represent any real number.
10 – A Binomial Coefficient, also known as the choose function. 5 choose 2 is equal to 5! divided by (2!*(5-2)!)
11 – A hexadecimal, or base-16, number.

Previous I can’t believe posts:

* I can’t believe someone makes… Yet More USB nonsense

* I can’t believe someone makes… Coca Cola powered cell phones

* I can’t believe someone makes… Cassette Tape Ties