How loud is really loud?

Question: Just how loud do the cheering, jeering fans get at a pro football game? (1) It's like being front row at a KISS concert. (2) It's a tempest in a teacup. (3) The noise is psychologically intimidating as well as physically challenging. (4) The sound stays pretty well-contained within the stadium and not much out beyond.

Answer: Check all of the above.

The loudest crowd ever recorded at a game, according to the Royal Association for Deaf People(!), was in 2000 in Denver, an undomed stadium, says Timothy Gay, Ph.D., in "Football Physics." It registered 128.7 dB (decibels), beyond the threshold of pain for most people and comparable to 120 dB for a rock concert.

Imagine the Bronco fans could have kept this up for four full quarters — i.e., four hours of nonstop yelling at an energy flux of 0.5 pound-force feet per second per square foot, almost a trillion times more intense than the sound of normal breathing. Still, if you put a teacup of water at midfield, the sonic energy would raise the water temperature less than 3 degrees F (tempest in a teacup). What this shows is the incredible sensitivity of the human ear.

As pure energy, the sound may not be much, but hearing 30,000 screaming hostile fans facing you in the end zone could put anybody off his game. Plus when the quarterback looks down the line at the receiver and audibles, he might as well be yelling into a jet engine. Nevertheless, says Gay, even at this volume, sound drop-off is so steep that by about half a mile from the stadium, crowd noise will be down to 80 dB, like traffic noise on a busy street.

Question: That everyday stuff you just put into the trash for pickup and disposal will still be undecomposed (1) a year from now. (2) when your kids grow up. (3) when your kids' kids' kids' ... grow up.

Answer: A year will undo orange peels and many other organics, if not overly compacted in a landfill or shielded by a plastic bag, says Jessa Forte Netting in "Discover" magazine. Your kids will likely outlast the paper (5 years), the plastic trash bag itself (10-20 years), and maybe the batteries (100 years). But for the glass bottles and plastic soda bottles, you'll need to tack on all the kids' kids' kids' ... you can muster, because at a million years' decomposition time, the glass bottles may well outlast the human race itself.

Still, the real endurance kings are plastic soda bottles, listed as "forever," making them immortal trash of sorts.