Science can look quite magical when taught with the right tools. Take this Horizontal Hand Boiler for instance: it is a fun physics toy that demonstrates the principles of thermodynamics. When you hold one side with your hand, the liquid inside moves to the other and looks like it is boiling. It works based on heat transfer and vapor pressure. When you hold one side, the heat from your hand transfers to the liquid and expands it. The higher pressure on one side pushes the liquid to the other side.
While you see the liquid boiling, it is really bubbling due to pressure. These toys are made in two modes. The vertical ones partly rely on gravity while the horizontal one isolates the effect. This is a great conversation starter and will be a hit for kids as they will want to know how one can boil liquids just with their hand.
