nobody knows, but arthur c. clarke has made an estimation, and he said it this way. behind every human being stands 30 ghosts, that 1/30 of all human race from way back is walking the earth today. that number's changing quickly. let's say one trillionth, so that means there were 30 more people on the earth from time zero than there are now. now there's about 4 billion. and there's 30 times that number for the total number of people that ever lived. 3 x 4 is 12, call this 100, that's like 10 to the 11, 10 to the 11 is 100 billion. so 100 billion people in the world. but the number of atoms in your lungs, 10 to the 22, what's that, billion, billion... 10,000 billion, billion atoms in your lungs. many, many, many more atoms in your lungs than people that ever lived, so you can rest assured that inside your lungs or inside your body at any moment are atoms from every human being who ever lived. you know how the buddhists say things like we are all one. we are all one. what do the physic-ers think about statements like that? the hardcore physic-ers, what do they say? it's