Actually nobody wants dead air, the term broadcasters use for radio silences during transmission, particularly those longer than, say, a cough — whence the term “cough button” for the switch on the announcer’s console used for brief silent interruptions of the studio’s live sound, in contrast with the pure tone, usually rendered as “bleep,” which has accordingly become ubiquitous participial euphemism for any swearword one cannot say on air, e.g., “Now wait just a bleeping moment.” (In the transcriptions of the tapes Richard Nixon rashly made of his conversations in the Oval Office, the equivalent of “bleep[ing]” was “[expletive deleted”].)  Dead air that last longer than a few seconds leaves the listener uncertain as to whether the station has gone off the air entirely or the announcer has taken a hike (whether to the bathroom or the next world) especially when occurring at the end of a track that’s playing from a turntable.

Human beings ordinarily breathe air in and out about 40 times a minute when newly born.  Healthy adults breathe somewhere between 12 and 15 times a minute when at rest, but 35 to 40 when exercising. An athlete in top condition and performing at peak, however, can breath as often as 60 to 70 breaths per minute. (Whence a favorite joke of one of our grammar-school teachers, raised in the days when boys wore knickerbockers: “His breath came in short pants.”) Of the air we breathe, 78% is nitrogen, which for metabolic purposes is irrelevant, although dissolved in the bloodstream it can cause lethal cramps (“the bends”) for underwater caisson workers who come to the surface too quickly rather than undergoing gradual decompression. By contrast, oxygen, which makes up almost all of the remainder (21%, the rest being carbon dioxide, helium, argon, and other trace gases) is absolutely essential to human metabolism, and if its supply to the brain is choked off, death is sure to follow.


Antoine Lavoisier

The Lavoisiers Taking the Air

Of the scientific revolutions throughout history one of the most dramatic centered on understanding the nature of oxygen and its role in both respiration and combustion. It was well known from ancient times that without air we suffocate and that fires deprived of air go out. By the mid-1700s, the prevailing belief among European “pneumatic chemists” was that there was a substance in air called phlogiston whose action extinguished flame, and when Joseph Priestley first produced something close to pure oxygen by heating red oxide of mercury, he believed it at first to be nitrous oxide; later he modified this conclusion and pronounced it to be ordinary air from which the phlogiston has largely been removed. It was left for his opposite number across the English Channel, Antoine Lavoisier, to isolate oxygen and to identify it as the element that joined with other substances in the process of combustion, and thus accounted for the added weight of the burnt product—a result flat contrary to the predictions of phlogiston theory. (Lavoisier’s fine brain would meet its own end by oxygen deprivation through exsanguination, as an immediate consequence of his being guillotined by Charles-Henri Sanson in 1794 at the height of the French Revolution.)

The English word air is actually a convergence of several etymons. The stuff we breathe comes from Latin āēr, ‘air as a substance, lower part of the atmosphere’ (this second meaning in contrast with aethēr, ‘ether,’ the upper “pure” air which in antiquity was
supposed to permeate the sublunar sphere and, later, all of outer space until its existence was disproved by Michelson and Morley’s definitive experiment in the early 20th century). Both āēr and aethēr were lifted straight from Greek (aēr and aithēr respectively, which explains why āēr is two syllables, whereas the ae– in aethēr is a diphthong), and in poetic usage, at least, retained the Greek accusative-case ending –a. But āēr soon got assimilated into ordinary everyday speech (Plautus was already using it familiarly by the time he wrote his Comedy of Asses in the early 2d century B.C.E.), such that the accusative form āerem became quite commonplace; from it French (and English in turn) derived air in the first two senses in the Petit Larousse: ‘gaseous fluid that makes up the atmosphere’ and ‘manner, fashion.’ The Latin poetic accusative āera, on the other hand, was the source for the Italian metathesis, aria, likewise borrowed into French as air in the sense of ‘song’– a convergence reminiscent of the Yankee’s answer to the motor tourist at the fork in the road that “the left one be straighter, but the right one be prettier.”