A friend and I were talking about RFID the other day. I told him how everything that is manufactured, everything, will have an RFID computer embedded into it, each with a unique identification number, in the near future (I'm talking 10 or 20 years). He didn't believe me. "Do you know how many numbers it would take to give everything that is manufactured a unique identification number?" he asked rhetorically.
Well, that got me thinking. Each bit has two states, on or off, plus or minus, 1 or 0. One bit, therefore, can represent two possible values. Ten bits can represent 1024, or one kilobyte (1KB), or two to the tenth power possible values. Twenty bits can represent 1,048,576 (1MB) possible values. Thirty bits can represent 1,073,741,824 (1GB) possible values. Forty bits can represent 1,099,511,627,776 (1TB) possible values.
How many bits do you think it would take to provide a unique number for every atom in the universe? You might be surprised to learn that two hundred fifty-six bits will do it with lots of numbers left over.