Voltages are often thought of as continuous physical quantities. I was wondering whether by zooming in a lot, they are discrete.
I feel like the answer to the above question is yes as voltages in the real world are generated by actions of electrons. Can someone give me a more formal proof or a disproof?
Whether voltages are discrete of continuous can have some impact the correctness of devices such as the analog to digital converter. For example, if voltages in the real world are continuous, then the Buridan principle says that there cannot be a perfect analog to digital converter because such a device makes a discrete decision from continuous inputs.
 : Lamport, L. (2012). Buridan’s Principle. Found Phys 42, 1056–1066. http://link.springer.com/article/10.1007/s10701-012-9647-7
(It would be great if someone could also answer a related question http://electronics.stackexchange.com/questions/126091/is-there-an-adc-with-a-finite-bound-on-measurement-time)