ABSTRACT
If you paid attention to the title of this chapter, you may be wondering why I called it “daily and circadian rhythms.” Are not daily rhythms the same thing as circadian rhythms? Yes and no. According to the American Heritage Dictionary, the adjective daily applies to something that happens or is done every day or once a day.1 A similar description is given for the adjective circadian (Figure 5.1). To understand the difference between the two words, we need to look at their histories.
