Ok then. Laptops have temperature sensors that can add entropy. A super small embeded device like a lightbulb should keep one of it's I/O pins open. A floating

Ok then. Laptops have temperature sensors that can add entropy. A super small embeded device like a lightbulb should keep one of it's I/O pins open. A floating wire also gives entropy. If the question is can you generate random numbers on a computer in a sealed room with absolutely no input, a static image loaded on it, and you have no storage devices to keep any sate, of course you can't generate a random number. The vast majority of things we put computers in do have some form of input that is random enough for a seed unless you design it that way on purpose.