An abundant source of energy nowadays is heat. it can be obtained in many ways such as from the sun. however with the advancement of science there are many ways how we can convert heat into other kinds of energy. One of the ways to convert heat into energy is through a heat engine. the heat engine is built in the most efficient and effective manner to absorb heat and produce an amount of mechanical energy. the most practical example where we can see how this is applied in real life are from old trains being fueled with charcoal.
According to the law of thermodynamics, gas molecules vibrate, and produces kinetic energy (like the wind) when in contact with heat. The higher the heat temperature then the faster and stronger these gas molecules move. If they are contained in a space, the molecules bounce and they create an amount of pressure. The force of the pressure depends on the tightness of space in the container. If we observe the video above, gas molecules inside the glass container are heated and produces pressure. To make this pressure to work, the machine attempts to compress the space making gas molecules inside produce higher amount of pressure thus forcing the machine to be pushed back. The machine then uses this force to make the wheel spin and then repeats the cycle and eventually stops when the gas molecules returns to their stable state which happens when heat is gone.