Energy harvesting that are able to operate in higher temperature gradients, and that can conduct electricity well without also conducting heat (something that was until recently thought impossible ), will result in increased efficiency. Future work in thermoelectrics could be to convert wasted heat, such as in automobile engine combustion, into electricity. This type of harvesting is based on the changing capacitance of vibration-dependent capacitors. Vibrations separate the plates of a charged variable capacitor, and mechanical energy is converted into electrical energy. Electrostatic energy harvesters need a polarization source to work and to convert mechanical energy from vibrations into electricity. The polarization
Feathers: The Evolution of a Natural Miracle feathered flight has influenced human aviation. Hanson describes the behavior of birds-of-paradise and the role of their elaborate feathers in sexual selection. Hanson also visits the Las Vegas Strip and observes how feathers play a role in pageant shows like "Jubilee!". Hanson interviews Marios Ignadiou, the head of "Jubilee!"'s costume shop, as well as fashion designer Pete Menefree. Hanson then describes the history of the feather trade in fashion. In the period before World War I, feathers were highly valuable commodities. Wanting to capitalize on the economic strength of feathers, the government of South Africa sponsored the Trans-Saharan Ostrich Expedition,