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**