“Ordinary lightning produced by thunderclouds is pretty hard to make artificially on a large scale, so there’s little military value. Our research objective is to produce dry lightning—that is, lightning discharged by an electric field produced in electrified air, with no involvement of clouds.”
“That’s what you said at Mount Tai.”
Lin Yun showed me two machines installed along a wall, each the size of a truck, that resembled enormous air compressors and consisted largely of high pressure airbags. “These are electrostatic air generators. They take a large volume of air, charge it, and then expel it. The two machines produce positive and negatively charged air.”
A thick tube ran from each generator along the wall at ground level, with thin tubes, more than a hundred in all, extending vertically along it at regular distances to two rows of nozzles affixed to the wall, one high and one low. Lin Yun told me that the one set of nozzles sprayed positively charged air, and the other negatively charged air, to form a discharge field.
Then I saw someone hoisting a small model airplane on a pulley high up into the space between the nozzles. Lin Yun said, “That’s the strike target. It’s the cheapest kind, only able to fly in a straight line.”
Turning around, Lin Yun led me into a small room in the corner of the building—a glassed-in iron cage, really—that contained an instrument panel. She said, “The lightning doesn’t usually strike over here, but for safety reasons, we built this shielded control room. It’s a Faraday cage.” She handed me a plastic bag containing a set of earplugs. “It gets very loud. You’ll damage your hearing without earplugs.”
When she saw I had the earplugs in, she pressed a red button on the console and the two machines roared to life, their nozzles high up on the wall spraying red and blue mist into the room to form a strange sight under the floodlights shining from the dome.
She said, “Charged air is normally colorless. To see more clearly, the charging process adds a large quantity of aerosol particles.”
The blue and red air accumulated, forming two even layers over our heads. On the console, a red number ticked, and Lin Yun told me it displayed the strength of the electric field that was now forming. After a few minutes, a piercing buzzer sounded to indicate that the electric field strength had reached the set value. Lin Yun pressed another button and the small plane that had been hoisted up began to fly. When it reached the space between the red and blue layers, there was a flash of lightning bright enough to white out my vision, and I heard a clap of thunder, still startlingly loud even though I was wearing earplugs. When my vision returned, I saw that the plane was in small pieces, like bits of paper scattered on the floor by an unseen hand, and at its final location, yellow smoke was slowly dissipating.
I was stunned as I surveyed the scene, and I asked, “Did that little plane trigger the lightning?”
“Yes. We brought the atmospheric electric field to a critical point, where any foreign object of sufficient size that enters the vicinity will trigger lightning. It’s like an airborne minefield.”
“Have you conducted outdoor tests?”
“Lots of them. But we can’t give you a demonstration, since a considerable investment is required each time the experiment is run. To release charged air outdoors, pipes with high and low nozzles are hung from tethered balloons that vent positively and negatively charged air. When building an atmospheric electric field, dozens of balloons—more than a hundred, sometimes—are lined up to form two lines of nozzles to produce the two charged air layers. Of course, this is only an experimental system. Other methods may be used in actual combat, such as release from aircraft, or from ground-launched rockets.”
I thought about this, and said, “But the air outside isn’t still. Currents will blow away the charged air layers.”
“That is indeed a major problem. Initially, we thought about continuous release upwind to form a dynamically stable atmospheric field over the defensive target.”
“And the results of actual tests?”
“Basically successful. And that success is why the accident occurred.”
“What happened?”
“Prior to conducting the atmospheric lightning generation tests, we considered all aspects of safety. Only if the wind direction was safe would we conduct the test. If, at any time during the test, the atmospheric field we created exceeded our expected stability threshold, it would be blown far downwind. During the test, there were constant reports of clear-sky lightning in the area downwind of the base, the farthest from around Zhangjiakou. But that lightning didn’t cause any damage, since it was the equivalent of a small thunderstorm. In most directions, the wind was safe. Even in the direction of the city we didn’t feel there was any particular danger, apart from one: toward Beijing Capital Airport. The atmospheric field is especially dangerous to aircraft, since, unlike thunderclouds, pilots and ground radar are unable to see it. To increase visibility, we added color, like what you just saw in the inside test, but we later discovered that over long distances the colored air separated from the charged air. Unlike the charged air, the colored air containing heavy aerosol ions dissipated quickly, so the color soon disappeared.
“We set up our own meteorology team to recheck wind direction data with the air force and local meteorological bureaus before each test, but even so, there were many sudden, unexpected changes in wind direction. On the twelfth test, the wind suddenly changed direction after the field was established, and the atmospheric electric field began drifting toward the airport. The airport had an emergency shutdown, and we dispatched five helicopters to track the drifting field. It was difficult and dangerous, since after the colored air dissipated, it was only possible to locate it through the changes in interference on the helicopter radios. One helicopter accidentally entered the field and induced lightning, and exploded when it was struck. The captain who was killed was the ball lightning eyewitness you want to see.”
The image of that young pilot came up clearly in my mind. For years, whenever I heard that someone died from a lightning strike, I felt an indescribable fear in my heart, and now this fear grew stronger. Looking at the red and blue fog hanging in midair, my scalp crawled.
“Can you get rid of the field?” I asked.
“That’s easy,” she said as she pressed a green key. Colorless air immediately issued from the nozzles. “The charge is being neutralized.” She pointed to the red digits indicating the field strength, which was dropping dramatically.
But my anxiety persisted. I could feel the invisible electric field everywhere, the surrounding space pulled taut like a rubber band, about to snap, and I found it difficult to breathe.
“Let’s go outside,” I suggested. Once out of doors, I could finally breathe a little easier. “That thing’s frightening!” I said.
She didn’t notice anything unusual about me, but said, “Frightening? No, it’s a failed system. We ignored one important point. Although we repeatedly measured the dependence curve between the volume of charged air and the volume and strength of the electric field, with promising results, the curve could be determined to within a small range indoors. It wasn’t at all applicable to outside space, where creating a large, external atmospheric field consistent with combat conditions meant a geometric increase in the amount of air to measure. Maintaining a sustained atmospheric electric field by continuously releasing charged air requires an enormous system—one that, even setting aside economic factors, would be an easy target under combat conditions. So you see now that our two experimental systems were failures. Or maybe, they were partially successful in technical areas, but have no combat value. As for the reasons they failed, I expect you have a deeper notion.”