Eli Yablonovitch blew me away today by pitching the thermal photovoltaic engine as a potential high-efficiency method for converting heat to electricity, a technology that could be used in cars, power-plants, spacecraft, and a variety of other applications. The talk was entitled "Is there anything it cannot do: Can Opto-Electronics Provide the Motive Power for Future Vehicles?" (EE3.8.01/NT1.8.01). The concept behind a thermophotovoltaic is that a photovoltaic can be used to convert the emitted photons from a sufficiently hot blackbody emitter to electricity. There are many questions, but that is exactly the point; this concept has been pitched to us as a potential heat-to-electricity converter that could operate at high efficiency (perhaps 50%) and that can be used in a form factor smaller than a textbook. Future science and efforts will reveal if this technology can be developed the way we hope. Dr. Yablonovitch is renowned as a forward-thinking physicist and engineer, and it is exciting to think that this technology could have potential revolutionary impact in the future.