> But if you want to talk about the fluctuations themselves, you want the chart to be full of those fluctuations, not anchored at zero and all the fluctuations

> But if you want to talk about the fluctuations themselves, you want the chart to be full of those fluctuations, not anchored at zero and all the fluctuations just little wiggles relegated to the top. Wouldn't you then plot the _fluctuations_ anchored at 0? Same with voltage, using some 'absolute' voltage value doesn't make sense. If you put ground and zero at 100V and the positive node to 105V, your 5V device will work just fine.