Optical technologies and the people who work with them have brought tangible social, environmental, health, and economic gains to humanity. A prime example is the solar cooker, designed for sunny and dry climates. Varieties of these have provided thousands of people with alternative sources for cooking fuel. The top five countries with ideal solar cooking climates are India, China, Pakistan, Ethiopia, and Nigeria. In the photo above, Sandipan Mukherjee demonstrates the popular use of solar cookers in a remote village in Nubra Valley, India. Off the national power grid, Nubra Valley is tucked away in a high-altitude, cold desert between the Himalaya and Karakoram mountain ranges. Solar-based technology plays a crucial role inthe village. Although it can be bitterly cold in Turtuk during the winter, the area still receives strong sun rays. The three types of solar cookers are heat-trap boxes, curved concentrators, and panel cookers. The solar cooker shown above is a curved ...