Robert Frank: Today’s question was posed by my former student Karim Abdallah. “Why,” he asked, “does a light come on when you open the refrigerator but not when you open the freezer?” The cost-benefit ...

It's a common situation: you open the fridge, and the light doesn't come on. So you decide to save the day and just swap in a regular bulb from the junk drawer. But before you do, you should know that ...

If you’re trying to stealthily swipe a midnight snack from the refrigerator, you’re in luck—the built-in light makes it easy to see what you’re doing. If your treat of choice is frozen, however, ...