Light as Air

Gabrielle Walker, science writer and author, previously, of the work Snowball Earth, has taken the title of her latest work from a letter written by one Evangelista Torricelli, "We live submerged at the bottom of an ocean of air." Torricelli, inventor of the barometer, was a contemporary of Galileo -- the man who weighed air and found it to be quite heavy. How heavy? Carnegie Hall holds 70,000 pounds of the stuff, which is, after all, the stuff of life and, as Walker notes, death as well. For more on the fascinating subject, Read William Grimes' enthusiastic review of Ms. Walker's An Ocean of Air in today's New York Times.