If an atom bomb detonates in the desert, does it make a sound?
This may not be quite as thought-provoking a question as the old “If a tree falls in a forest” riddle, but in 1951, American scientists pondered it nonetheless.
Of course, they knew an atomic explosion made a sound — a big one. They just wondered how far away that sound could be detected.
And so they built three huge microphones in Washington.
The atomic test was called, in the jaunty nomenclature of the day, Operation Buster-Jangle. Seven nuclear devices in all were to be set off at the Nevada proving ground. Four bombs were dropped from aircraft, one was detonated atop a tower, one was detonated at surface level and one was detonated underground.
The test started Oct. 19, 1951, with the explosion (or the attempted explosion; more on that later) of the bomb called Able. The final bomb was called Uncle, detonated Nov. 29, 1951.
The Defense Department and Los Alamos were busily scrutinizing all sorts of things with tests such as Buster-Jangle, but the element that fascinates me is a 135-page document that Silver Spring reader Michael Ravnitzky found online. Published by the Armed Forces Special Weapons Project, it has the snappy title of “Detection of Airborne Low-Frequency Sound From the Atomic Explosions of Buster and Jangle.”
The seven tests were among 100 conducted in the desert about 70 miles north of Las Vegas. As the narrator in a 1951 film prepared by the Air Force (and available on YouTube) put it: “What good are atomic weapons without full knowledge of what they can do and how we can be protected against their effects?”
The first Buster-Jangle bomb, Able, was a dud. Bad wiring kept it from detonating on the first try. When it did finally explode, it had a smaller yield than expected. But the other bombs went off without a hitch.
Besides testing the A-bomb designs, Operation Buster-Jangle tested everything from tents and uniforms to runways, minefields and air raid shelters, all of which were built near ground zero. Dogs were anesthetized, put in protective garments and placed in cages. Water towers were erected to see how long the water stayed irradiated in “the valley where the tall mushrooms grow,” as the narrator memorably described the testing ground.
And 2,100 miles away, people were listening. Microphones were built at three sites in the District: at the reservoir at Foxhall Road and Whitehaven Parkway NW, at Dalecarlia Reservoir and at the Bureau of Standards, which at the time was on 36th Street NW. They were among 11 listening posts scattered from Hawaii to New Jersey.
The microphones were constructed from metal piping up to 1,000 feet long that were connected to a flexible diaphragm. Since sound is a pressure wave, the hope was the sensitive units would be able to detect changes in air pressure caused by the atomic explosions, even if human ears were unable to hear the sounds. Scientists had noticed such an effect when the 1883 eruption of Krakatoa volcano and the 1908 Siberian meteor strike were detected on barometers thousands of miles away.
Did it work? Yes. The bombs were detonated in fall 1951, and though it took up to three hours, the sound of each one reached Washington, causing the inked needles on the recording equipment to sketch herky-jerky mountainscapes.
As the report put it: “A signal from an atomic explosion seems to have a characteristic sound which can be detected even when the background noise is strong. The sound is very roughly similar to that which one hears in a train when another train passes, going in the opposite direction.”
The reason we cared was so we could detect when the other guys tested a nuclear weapon. The nuclear arms race meant not just making sure our weapons worked but knowing what the Russians were up to. The infrasonic microphone created by the Bureau of Standards also was useful for measuring tornadic storms.
Karen L. Green, curator of the National Atomic Testing Museum in Las Vegas, hadn’t heard of Washington’s microphone tests but recognizes them as part of the Cold War’s huge research push. Veterans of that war routinely send her stuff for the museum’s collection. Just to be on the safe side, she checks it with a Geiger counter before opening it.
“The interesting thing for me is that so many of the things that were developed for the nuclear testing programs developed into something we use even today,” Karen said. That includes high-speed film, 3-D film and the cameras that could shoot them. Like proud parents, scientists wanted to see what their children looked like.
And, as I discovered, sounded like.
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For previous columns, visit washingtonpost.com/johnkelly.