Watch art in motion with Hand Boiler! The heat from your hand appears to make the liquid in the bottle boil. This is a result of Charles' law by Jacques Charles.
In 1787, Charles discovered that a gas' volume is proportional to its absolute temperature. At a constant pressure (inside the Hand Boiler's glass), the gas' volume increases as the temperature increases. This means the heat from your hand causes the gas inside the glass to expand enough to displace the liquid. Make science fun!