Music in The Clouds

 

In June 1867, James Glaisher, an English astronomer and meteorologist, and an avid balloonist, was floating over Paris in a balloon when he entered an area of dense cloud:

This was not the first time Glaisher had heard music while flying through the clouds. Five years ago, Glaisher took off in a balloon over the city of Wolverhampton, England. At an altitude of 12,700 feet, he clearly heard a band playing music.

In 1867, Glaisher, together with other balloon enthusiasts, in particular, Camille Flammarion – a French astronomer, and Gaston Tissandier – a French meteorologist, began a series of experiments with balloon flights, and in two days, Flew from Paris to Solingen near Cologne. , Glaisher mentions hearing music and various voices several times during this trip while floating above the ground at an altitude of thousands of feet. “As we passed over Antony and Boulainvilliers we were charmed by some excellent orchestral music; Then we were completely surrounded by clouds, and each of them was about 3,280 feet above the city.''

What Glaisher and his colleagues experienced was the effect of humidity on sound level. It has been observed that as humidity increases the noise level also increases. "Clouds and fog, being more humid," explains Glaisher, "collect sound with such intensity that whenever, passing through a cloud, we have heard a band playing in a city below us, the music Always seems close to us.”

The NPS explains, "Low humidity absorbs more sound, especially at higher frequencies, due to "molecular relaxation" in the gases in the air (10% humidity level absorbs the most). "A large increase in atmospheric pressure The change, which is equivalent to thousands of feet in altitude, has a small effect on noise levels for most sources, but significantly affects the received levels of those sounds."