Not so long ago, a friend texted me from a coffee shop. He said, "I can't believe it. I'm the only one here without a tattoo!" That might not seem surprising: a quick glance around practically anywhere people gather shows that tattoos are widely popular. Nearly one-third of adults in the US have a tattoo, […]
All of us have an internal clock that regulates our circadian rhythms, including when we sleep and when we are awake. And light is the single most important factor that helps establish when we should feel wakeful (generally during the day) and when we should feel sleepy (typically at night). So, let me ask you […]
