The first diesel engine, invented by Rudolph Diesel in 1893. While a student at what is today the Technical University of Munich, Diesel learned of the poor efficiency of the steam engine and studied the theory by the French physicist Sadi Carnot, whose cyclic process promised considerably higher energy efficiency. Diesel made a note in his lecture script to attempt to realize the Carnot cycle. The result of his studies was to be the diesel engine, which to this day remains the most efficient thermal engine.