https://www.khanacademy.org/science/electrical-engineering/ee-circuit-analysis-topic/circuit-elements/v/ee-passive-sign-convention

Sign convention for passive components



I have to disagree...

Under certain circumstances, all three of the passive components which you summarize, such as: resistors, capacitors and inductors, can sometimes amplify signals by putting their impedances and resistances to good use. I have simulated this so many times that it is no longer shocking.

Energy can also disappear.

The simulator doesn't even give a hint from where this extra energy is coming from, nor where it is disappearing to. So, I am left to speculate that the isolation of systems of energy is a fiction. The editors over at Wikipedia seem to agree...

Quote...
https://en.wikipedia.org/wiki/isolated_system

"Classical thermodynamics is usually presented as postulating the existence of isolated systems. It is also usually presented as the fruit of experience. Obviously, no experience has been reported of an ideally isolated system."

Maybe a reversal of current, or some other artifice, is pumping energy into the circuit - against the higher voltage gradient accumulating within the circuit - from the lower voltage gradient in its environmental surroundings?

I've certainly seen indications that this is possible under simulation...

https://en.wikipedia.org/wiki/Electricity_theft#Inductive_Coupling