Igniting the cotton inside the clay pot without any open flame seemed quite incredible, but in fact, no Divine Power was used.
In physics, this phenomenon is usually referred to as adiabatic compression.
According to the first law of thermodynamics, mechanical energy and thermal energy can be converted into each other.
What Clara did was actually a simple piston device, through which she converted the work done by pushing down an iron rod into internal energy, raising the temperature inside the jar to the ignition point of the cotton, thus igniting it.
The most widespread application of this phenomenon is in the diesel engine.
However, Clara discovered this while Li Yu was pumping up a basketball; she noticed the outer wall of the pump was warm to the touch.
Li Yu, having nothing else to do at that moment, recreated this classic physics experiment with her.
At that time, the little maid had no idea that one day she would need this experiment to save her own life.
