I was looking at the reason as to why a Carnot Engine and watched this video on KhanAcademy. He used a very clever method of proving this by using the method of contradiction.
First he took the new Better Engine and added to an up scaled reversed carnot engine to show that the new device formed will not obey the Second Law of Thermodynamics.
However instead if we use the Carnot Engine itself instead of the better engine and a very low efficieny engine instead of the carnot, then wouldn't it prove that carnot's engine is the worse one.
This arguement can also be used to prove that no engine is more efficient than another.
Where am I getting it wrong?
I looked at other similar questions but none of it gives the answer.