Rock concerts and jet engines at take-off can boggle the mind with their extreme noise, and eventually deafen you. I’ve talked to young store clerks who clearly have hearing loss, presumably from concerts and not standing by jets. The king of all noises is at the launch of a large rocket.
In the March 2024 issue of Physics Today, Kent Gee and colleagues cited the noise of the venerable Saturn V rockets powering Moon launches. In addition to their phenomenal mechanical power (60 million horsepower in common units) the launches generated 1/3 of a million horsepower as sound. The authors equate that to the sound of 10 billion lawnmowers. The new (and fault-plagued) Starliner rocket slated to carry astronauts to the Moon generated sound levels of 146 decibels, well above the pain threshold, at 1.8 km away.
Rocket noise is composed of many different tones or frequencies. Low, thundering tones mostly come out behind, while high screeches come out mostly to the side. The physics of it is well-known. How about the “cure”? First, the cure is needed to limit damage to animals in a wide area, but also to structures and to the payload in the rocket. Imagine the 120 Space-X launches this year. Partial cures for the sound include massive water releases at the launch pad and flame trenches. Still, it will always be monster noise. New Mexico is close enough for me!
This has been an outreach activity of the Las Cruces Academy, viewable at GreatSchools.org.
Source: Physics Today, March 2024, pp. 46-47.
