Hello, I have a general question about computations, like many of the mathematicians around here we are constantly asked to answer. What is the use of all the computations you guys are doing anyway and what is the purpose of all this, etc. My favorite answer for this stupid question is : you know just take a smart phone, suppose you are somewhere and you receive a call and then you decide to send a photo of the place you are to that person , a 'mms' message. The message would contain the gps location + the image, etc. The amount of computation to do that simple thing is huge. This is where I loose most people because, to begin explaining all the mathematics behind this action is too much to explain in 2-3 phrases. So here is my question, in this example, how much computation is needed to perform the call first and then the sending and reception of the mms message containing the photo with the gps location : can this be evaluated ?? My guess is : something like 10^10, ? 10^12 ? Here the computation would include, the call process, the processing of the photo, the GPS thing, the reception, the location of the person you call etc. All of the operation combined. Any guess someone ? Best regards, Simon PLOUFFE