A Son of the Rock

Being of a mathematical bent I just love this equation Ian Sales has posted on his blog:-

It purports to give a mathematical expression to how Science Fiction works.

I immediately recognised its similarity to the Drake Equation:-

which tries to estimate the number of detectable extraterrestrial civilisations in our galaxy, the Milky Way.

See his post for the full argument but in Sales’s equation the terms are:-

W = wonder
l_g = greatest distance mentioned in the text
t_g = greatest length of time mentioned in the text
N_n = number of ideas/nova in the text
N_f = number of ideas/nova reader has encountered previously
i_r = closeness of the viewpoint character to the reader as a function of background, worldview, attitudes, etc – ie, an indicator of their ability to identify with the character
j_n = number of situations of jeopardy for point-of-view character(s)
j_a = amplitude of situations of jeopardy for point-of-view character(s), where 1 is fatal
C_n = size of cast in the text
B_r = bandwidth of the reader (calculated from educational level, number of books read, age)
D_r = willingness of the reader to suspend disbelief.