Throughout the electrified world, people turn lights on at dusk, and leave them on until dawn. In this post, we’ll look at the most obvious of these lights: those outdoors. Bright Planet The light bulb has come a long way since its dim beginnings in the 1800’s. We have become a planet whose glow can be seen from space, and where many places at night are as bright as day. Today, lighting consumes 25% of the world’s energy.i This image of Earth’s city lights was created with data from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS).ii Why light? People have better vision during the day than the night. At night, our acuity may be reduced to 20/200 or less. We lose…