Via Miss Cellania, we not only learn the rather elegant physics and chemistry behind those sippy bird toys but also that researchers have given it an upgrade as a device to generate energy.
Sometimes mislabeled as a perpetual motion machine, the thirsty mechanism is a heat engine, two evacuated glass bulbs linked by a tube pivot on a crosspiece and turns the temperature gradient along the body into a pressure difference that translates to the mechanism. Water evaporates from the head (usually adorned with something absorbent like felt) and lowers the temperature and pressure and causes some of the vapour in the chamber to condense (usually ether, alcohol or chloroform) and the liquid is forced up the neck, causing it to tip forward. The ambient air temperature warms the bottom bulb and causes the cycle to repeat. The toy, originally called a
Pulshammer was a German invention improved by Benjamin Franklin, after seeing one in action around 1768 and illustrates the principles of capillary action, wet-bulb temperature, heat of condensation as well as several laws of thermodynamics and idea gases and with the latest modifications also demonstrates the triboelectric effect (static electricity), harnessing it to power small appliances and seems overall like a pretty good educational apparatus, provoking thought while charging. Who knew? More technical details and a video demonstration of the prototype at the link above.
synchronoptica
one year ago: assorted links to revisit, Yugoslavian fashion plus climbing Everest (1923)
two years ago: more links to enjoy, two probes passing in the night, more shibboleths plus Arnold Schwarzenegger makes an appeal to the people of Russia
three years ago: RIP Yaphet Kotto, more links worth the revisit, Motown on tour (1965), mourning rings, fear of covering up plus the fashions of Birgitta Bjerke
four years ago: an iconic photograph from the battlefield (1942)
five years ago: Transit Driver Appreciation Day
