Bing Crosby was famously dreaming of a white Christmas, and so were many Americans this snowless holiday season. But a review of historical documents, archival photographs and press clippings shows that GE scientists led by Nobel Prize winner Irving Langmuir mastered the technology of coaxing snow out of clouds in the 1950s, half a century ago. Time magazine even put Langmuir on the cover with the headline “Can man learn to control the atmosphere he lives in?”
Langmuir’s weather research was code-named Project Cirrus. It was an outgrowth of a war time study to prevent aircraft icing and improve radio communication inside winter storms. Langmuir, a polymath scientist who won his Nobel for work in chemistry that led to GE’s early coronary artery imaging technology, teamed up with his protégés Vincent Schaefer and Bernard Vonnegut to figure out the science of snow. Such questions were in the air back then. “Why was it that sometimes snow forms so easily, with no apparent lack of nuclei on which crystals can grow, and at other times there seemed to be none?” asked the G-E Review magazine in November 1952.
(Bernard Vonnegut’s brother, the novelist Kurt Vonnegut Jr., worked in GE’s advertising and publicity department in the late 1940s. He famously fictionalized his brother’s cool science in the classic novella Cat’s Cradle, where a substance called Ice-Nine instantly freezes all liquid water on Earth.)
Snowball’s chance: Irving Langmuir, Bernard Vonnegut, and Vincent Schaefer are seeding a snow cloud.
Langmuir and his team learned that snowflakes form when the water temperature inside clouds falls well below the freezing point and the supercooled water droplets come into contact with tiny ice crystals. Schaefer tested the hypothesis on a hot summer day at GE’s Research Labs in Schenectady in 1946. He dropped a large piece of frozen carbon dioxide, or dry ice, into a cold box to lower the temperature. He lined it with black velvet to see better what was happening in the box when he shone a light beam inside. “In an instant, the air was full of ice crystals,” reported G-E Review.
Following Schaefer’s discovery, GE put out a press release stating that “man-made snow, every bit as real as that which makes for a ‘white Christmas’ has been produced for the first time” in the lab and that the technique could “make actual potential snow … when and where man wants it.”
A modified B-17 bomber used for cloud seeding.
By then, Schaefer was ready to move out of his cold box. On November 13, 1946, he and pilot Curtis Talbot took off from Schenectady Airport and scattered six pounds of dry ice in “a fleecy cloud four miles long that was floating over nearby Massachusetts,” Time reported. “Almost at once the cloud, which had been drifting along peacefully, begun to writhe as if in torment. White pustules rose from its surface. In five minutes the whole cloud melted away, leaving a thin wraith of snow.”
According to Schaefer’s lab notebook, “while still in the cloud, as we saw the glinting crystals all over, I turned to Curt and we shook hands as I said, “We did it!””
the dry ice fell too fast through the clouds and affected the supercooled water inside only briefly. Langmuir wanted a substance that would stay in the cloud and float around. Bernard Vonnegut cracked the problem when he sprinkled clouds with purified silver iodide. Silver iodide’s crystals resemble ice and they tricked water molecules into forming snowflakes around them. “Here apparently was a tool of almost miraculous potency,” wrote Time. Langmuir calculated that pure silver iodide was so powerful that only 200 pounds of the stuff would be enough to seed the planet’s entire atmosphere.
The first cloud “made” by the GE team.
Langmuir and his team then moved from snowfall to hurricanes. They found out that clouds seeded with snow-forming nuclei at a certain elevation tend to dissipate. In 1947, Schaefer flew into a B-29 bomber into a Florida hurricane and dropped 80 pounds of dry ice inside the storm. The storm, however, was “too complex” for conclusive data. Still, Langmuir ventured that “the chances are excellent that, with increased knowledge, something can be done. The stakes are large and … I think we should be able to abolish the evil effect of hurricanes.”
Langmuir moved on, but last month scientists from China’s Orwellian-sounding “Beijing Weather Modification Office” attracted attention for shooting rockets and sending fighter jets to “seed the clouds” with rain to fight drought and clear up air pollution.
Perhaps it’s time to open those old Langmuir files again.