Sigh...

Hey, Matt:

Why do we sigh? And on an unrelated note, do the toilet seat covers in public restrooms actually do anything?

— Amy, sitting and sighing

In with the good air; out with the bad air. The best science can say about sighs is, they slow heart rate and relieve stress. Shallow breathing causes carbon dioxide to build up in our blood, and a good, deep sigh helps us get the O2 in and the CO2 out. And if you're lucky, a good deep sigh also gets somebody to come over and say, "Aw, cheer up, Amy" and give you ice cream. On an unrelated note, toilet seat covers mostly litter up the already funky floor. The Clorox company paid a University of Arizona microbiologist to do germ counts on common office surfaces. According to his study, you'd be smarter to eat lunch off a toilet seat than off your desktop or the lunchroom table. Your telephone? Computer mouse? Infested. Other studies have also shown that while the underside of a toilet seat can be pretty germy, the top of the seat is relatively benign. Toilet seat covers protect our sensibilities, not our butts.