Brian James needed a light bulb. Just one little bulb to replace a 40-watt light that burned out in his stairwell. How hard can that be? Pretty hard, it turns out. “I’m balancing the expense ...

To compare apples to apples, I tested only LED bulbs that aim to replicate the classic 60-watt/800 lumen incandescent bulb. A little spec-splaining: Watts measure energy use, lumens measure ...

NASA is changing all of the light bulbs on board the International Space Station to help famously insomniac astronauts sleep better.