DJPhi

Actually, what you heard IS correct, but only if you insert the word "potential" into that sentence. There are actually approximately 3.75 x 10^1,056,570,551,815 possible unique connections for 100 billion neurons. However, the human brain is thought to contain more than 100 billion neurons. This outnumbers the number of atoms in the known universe (estimated anywhere from 10^77 to 10^88 atoms, depends on who you ask) by at least 10 billion orders of magnitude, which means that there are 1.06 x 10^12 times more possible unique connections in a human brain than atoms in the universe. The way you arrive at that muligoogolplex of a number is by using factorial notation. For example say we only had 10 neurons, how many unique connections can we make? Well, rather than just counting up the number of possible connections (10+9+8+...+1) you need to treat each pathway as a variable and find the number of unique ways to connected every point to everyother point. For example the signal can travel from neuron 1-2-3-4-5-6-7-8-9-10 or 1-3-2-4-5-6-7-9-10..etc To calculate the number of unique pathways, you need to use (n-1)! So, with ten neurons you have (10-1)! = 10! = 10*9*8*7*6*5*4*3*2*1 = 3,628,800. When you use this standard formula to finding the number of possible permutations for connections of neurons in our brains you end up with almost uncalculatable numbers. For instance 1! = 1 10! = 3,628,800 100! = 9.33 x 10^157 1000! = 4.02 x 10^2,567 ..... 10,000,000,000! = approx. 2.33 x 10^95,657,055,186 100,000,000,000! = approx. 3.75 x 10^1,056,570,551,815 That number is so large it is for all intents and purposes, infinity. I ve done this calculation using approximation software which uses the Stirling approximation function. It uses a logarithmic version of the classical iterative method of factorial notation (n-1)! used for smaller n values. The Stirling approximation is desribed as follows: n! ~ n^n x 10^(-n) sqrt(2*pi*n)(1 + 1/(12n)) Well, there you go. i hope that clears up the seemingly paradoxical question! We have remarkable brains. The most complex machine in the universe is sitting in between your ears.