We see it all the time. Meteorologists going on and on about the heat index. But what is the heat index? It’s a number that we get from this big, long equation. It looks something like this… HI = ...

Wind chill and heat index are often both referred to as the "feels-like temperature." Of course, heat index tells us the real feel over the summer, and wind chill tells us the real feel in winter.

THE alarm rings. You glance at the clock. The time is 6.30 am. You haven’t even got out of bed, and already at least six mathematical equations have influenced your life. The memory chip that stores ...