I have always been fascinated with using imaginary numbers to understand spacetime.  Complex number format is A+Bi.  A and B are variables and "i" is the imaginary number.  An imaginary number is the square root of -1.

 

Bi is the atomic symbol for the 83rd element on the periodic table of atomic data (called Bismuth).  Bismuth has the highest Hall effect of any metal, and is the most diamagnetic of all metals.  It also has the lowest thermal conductivity of all the elements except mercury.