Tasteless Salt and Invisible Light

Experts say that the strongest cue for waking up isn’t sound but light. Our brains process light as the surest sign that it’s time to be awake.

Salt, something that most people consider to be a common household item, is a useful substance for many things including flavoring, cleansing, and preserving.

Jesus told his original disciples, “You are the salt of the earth . . . You are the light of the world” (Matthew 5:13–16).