Beyond Zero and One (Andrew Smart) / quote 61 of 171
Voltage values are a human invention
As I mentioned, when voltage is measured and digitized using signal processing technology, the probability that the real voltage on a computer chip has a particular value is negligible. This is a subtle but very important point. It is the fundamental fact about moving from the analog to the digital. When we measure the voltage coming across a computer circuit, the computer assigns the voltage a certain value, like 1.3597 volts, which can either push the logic gate into Logical 1 or Logical 0 depending on where the thresholds are set or what kind of chip it is. The precision of this value goes out to however many places to the right of the decimal point the memory in the system can support. No matter what the precision of the number is, I want to emphasize that this is not the real value of the voltage in the physical world. In fact the unit of measurement “voltage” itself is a human invention.…