Ball Lightning

by Cixin Liu

  “We can only take it a step at a time,” Lin Yun said.

  “Indeed. If you’re really able to find ball lightning, it will be a great success for science. And a bit of success for our base as well. But I’m worried about safety. I’ve got an idea: Can’t we put the lightning generator into a car, and have cars drive the electric arc along level ground? The arc would still be able to sweep a large space.”

  Lin Yun shook her head. “We’ve thought of that. And we’ve thought of using ships to drag an electric arc over the ocean. But it won’t work.”

  Colonel Xu thought for a moment, and then nodded. “Right. The earth and the ocean surface are both conductors, so the induction effect won’t permit a long arc.”

  “We also considered using fixed-wing aircraft, which would make parachuting out in the event of an accident somewhat easier compared to a helicopter, but that won’t work either, since air currents at that speed would blow out the arc. We’ll try to adopt as many precautions as possible prior to the actual experiments, like training the pilots to parachute from helicopters under abnormal flying conditions. In addition, naval aviation is introducing an ejection device for helicopters, similar to the kind in fighters, except along the horizontal. We’ve already requisitioned a few from the General Armaments Department.”

  Colonel Xu shook his head. “These measures won’t have a significant effect. We’re taking a big risk.”

  Lin Yun said, “That is true. But judging from the present situation, with the whole army in second-degree combat readiness, safety isn’t our top priority.”

  Her words may have surprised me, but Colonel Xu tacitly accepted her opinion. He seemed like a nice guy, and couldn’t really do anything about Lin Yun and me. On the other hand, with the current state of things, it was time for soldiers to take risks.

  *

  The base currently had two domestic-made WZ-9 helicopters. Before the tests formally began, their pilots, two lieutenants, conducted a weeklong parachute training, one of them at the controls doing stunt flying that mimicked plummeting as the other jumped out the rear hatch. They also tried out the ejector, a small rocket affixed across the back of the pilot seat; when triggered, the helicopter would emit a puff of smoke as if it had been hit, and then the pilot would be thrown out of the hatch like a stone for a considerable distance until his parachute opened. It was thrilling to watch.

  Once, during a break, a pilot asked Lin Yun, “Major, are we likely to be hit by something? If it’s like what happened to Captain Wang, then practicing this is useless, I’m afraid.”

  “The lightning will be far weaker this time. If the aircraft is unexpectedly hit, it won’t cause that extent of damage. The actual test will take place at five thousand meters, so you’ll have plenty of time to jump.”

  The other pilot said, “I’ve heard that I’m going to be shooting lightning at another helicopter.”

  “That’s right, but the strength is only as high as what you use to drain the residual battery charge.”

  The lieutenant broke out laughing. “So you want to use this weapon in air combat? A weapon only capable of firing one hundred meters? In air combat?”

  “Of course not. Your two aircraft will pull that electric arc through the air like a dragnet to catch—or, rather, excite—a structure that might be present there. If it’s discovered, the object might be a powerful deterrent weapon.”

  “Major, this is all getting really weird. To tell you the truth, I don’t have any confidence in you people anymore. I just hope that I can finish this quickly and return to my unit.”

  When the lieutenant mentioned Captain Wang Songlin, who had been struck by lightning from an artificially charged cloud, my heart tightened. I imagined what I’d be like if I had to face such a danger in flight—no question I’d be consumed with terror. On the other hand, if I were Lin Yun, I’d still be unable to speak frankly about it to the two pilots. But their young faces before me looked unperturbed, as if they were only taking a car on a trip to the suburbs.

  Later, we came up with many more ways of increasing the safety of the experiment. The one that seemed the most feasible was hanging the lightning generator from a cable attached to the bottom of the helicopter; if it was long enough, it would completely resolve the safety issue. We cursed ourselves for not coming up with such a simple scheme earlier. Then tests showed it wouldn’t work, as the swaying of the suspended generator was severe enough to make precise targeting impossible, and we ultimately had to return to our original, risky plan.

  But before that, I grew curious about the principles behind the lightning generator. Even though it had a range of just a hundred meters, using the generator’s small electrode to discharge over such a distance was practically impossible, and maintaining an arc harder still. Because of the secrecy involved, it wasn’t appropriate to ask too many questions, but when I first saw the outside of the system, I discovered a peculiar piece of equipment. It was a short, thick tube set very close to the electrode. One end pointed in the direction of discharge, and the other was inserted into a large-volume device which—judging from the cylindrical shell and the high-voltage wires that wrapped it—appeared to be a small particle accelerator. I decided that it must be connected in some way to the secret of long-distance discharge. Later I found out it was a beam emitter that fired a stream of charged particles at the target prior to electric discharge. The particles ionized the air to form a discharge path that guided the arc to the target.

  The weather was good the day of the first test. There was practically no wind at ground level in the early morning. Everyone involved in the project was at the test site. We were few in number: just twenty-odd engineers, staff, and ground crew. An ambulance was parked not far from the helicopter pad, the medics in their snow-white uniforms conspicuous in the dawn light. I had an odd feeling, and got a vague sense of fear from the two empty stretchers sitting on the grass. But the men who might be carried on those stretchers before long were standing beside them joking easily with the two pretty nurses they’d just met. My sense of inferiority came welling up again. The stormy night that had decided the course of my life had given me a far deeper fear of death than most people.

  Lin Yun came over with two yellow jumpsuits for the pilots to put on. “These shielded uniforms are from the municipal power bureau, where they’re worn by workmen doing jobs on live high-tension wires. They’re shielded using the principle of the Faraday cage and will offer some protection against lightning.”

  One pilot laughed as he took the shielded uniform and said to Lin Yun, “Don’t worry, Major. Your little electric arc won’t be any worse than a Stinger missile.”

  Lin Yun described the test procedure for them: “First, ascend to five thousand meters, and then bring the two craft as close together as is safe. When you’re at that distance, ignite the arc, then gradually separate the two craft and hover just under the arc’s maximum range. Then fly forward at the speed given by the ground commander. Pay attention to arc stability and hover if you need to—you’ve done that before. One more thing to watch out for: if the arc goes out, then disengage as fast as possible and turn off the generator. Don’t try to reestablish the arc, since if it’s ignited at long range, it may strike the aircraft! Make sure you remember that. Don’t die a martyr.”

  According to the plan, the helicopters would fly with the wind to minimize the relative airspeed. Then they would ignite the arc and fly for a while until it went out, at which point they would come back and repeat the process.

  The test helicopters quickly ascended to the predetermined altitude. At this point we had to use binoculars to see them. They flew with the wind and drew closer to each other until it looked from the ground like their rotors were practically touching. Then a bright electric arc appeared between the two craft, projecting a dim yet crisp popping sound down to earth. The helicopters slowly separated, and the arc stretched out, its initial straight line becoming more turbulent as the distance increased. At maximum separ
ation, it seemed like a piece of light gauze dancing on the wind, liable to slip its bindings and fly off into the sky. The sun was still below the horizon, and the bright blue-purple electric arc looked unreal against the dark blue of the sky between the helicopters’ black silhouettes, like the projection of scratched film on a cinema screen.

  I had a sudden chill, my stomach tightened, and I began shivering uncontrollably. I set down the binoculars. With the naked eye, all I could see was a blue dot high in the sky, like a nearby star.

  When I picked them up again, the helicopters were flying forward at maximum separation, taking with them that dancing, hundred-meter electric arc. Their speed was so low that it was only by comparing them to the thin high clouds, lit by the sun below the horizon, that you could tell they were moving. As they flew east, their sunlit bodies turned into two orange dots, and the arc dimmed slightly.

  I exhaled, but then heard shouts from the binocular watchers beside me. I grabbed up my own pair to catch the scene: on the receptor side, the arc had forked. Its main branch still contacted the electrode, but a smaller branch moved erratically along the helicopter’s tail like it was a thin hand searching for something. It lasted only three or four seconds, and then the arc went out altogether.

  The situation didn’t look scary and seemed unlikely to have any disastrous consequence on the helicopter. But I was wrong. The instant the arc vanished, I saw a bright light in the tail rotor. It vanished immediately, but then smoke appeared at that spot, and shortly after, the helicopter began to rotate, faster and faster. Later I learned that the lightning had struck a control line for the tail rotor, causing it to stop. Since that rotor was used to balance the rotational torque generated by the main rotor, once it lost power, the helicopter began to rotate in the opposite direction from the main rotor. Through the binoculars I saw the rotation accelerate and the helicopter gradually lose lift, then start a shaky fall.

  “Bail!” Colonel Xu shouted into the radio.

  But just seconds later, it looked like the pilot had restarted the tail rotor. The rotation of the fuselage slowed, as did the speed of descent, until it once again hovered in the air—but only for a split second. Then, like a clockwork toy, it started to turn again and plummet.

  “Bail!” Colonel Xu shouted again.

  After a short fall, the helicopter again stopped rotating and slowed to a hover. The next instant it began falling again... and the cycle repeated. Now it was below the safe altitude for parachuting. We could only pray that it reached the ground when it was near a hover state.

  When it landed off to the east, its speed had slowed significantly, but it was still far faster than a normal landing. I looked fearfully in that direction and waited numbly. Luckily, no smoke came from that stand of trees.

  When we drove up to the crash spot, the other test helicopter had already landed nearby. The site was in an orchard. The helicopter was tilted, crushing a few fruit trees beneath it, and the tops of several other stocky trees around it had been severed by the blades. The cabin glass had shattered, but apart from that, the fuselage did not appear to be seriously damaged. The lieutenant was leaning against a tree pressing a bleeding arm, impatiently trying to push off the nurse and stretcher carrier, but when he saw Lin Yun he used his unharmed hand to give her a thumbs-up.

  “Major, your lightning weapon took out a plane!”

  “Why didn’t you bail out?” Colonel Xu, who had just arrived, asked in exasperation.

  “Colonel, we army aviators have our own rules for when to bail out.”

  In the car back to the base, I couldn’t hold back one nagging question, and said to Lin Yun, “You were the designated ground commander for this test. But it was Colonel Xu who gave the order to parachute.”

  “It was very possible that Lieutenant Liu would be able to rescue the helicopter,” Lin Yun said evenly.

  “There was only a fifty percent likelihood of that. What if he couldn’t save it?”

  “Then the experiment would be suspended for quite some time, and the project might even be canceled.”

  My stomach turned another somersault. “If you were commanding an attack and there was a minefield in your path, you’d order the soldiers to push through, right?”

  “Under the new military regulations, female officers may not serve as front-line battlefield commanders.” As usual, she lightly deflected my question. She added—as if by way of apology for perhaps being too curt—“The military has its own form of conduct, somewhat different from yours.”

  “The colonel isn’t military?”

  “Of course he is,” she said lightly, a faint contempt noticeable in her tone. She held the same contempt for everyone in the base leadership.

  That afternoon, the helicopter underwent emergency repairs at the crash site and then flew back to base.

  *

  “Until there are effective measures to guarantee safety, the experiment must stop!” Colonel Xu said resolutely at the base meeting that night.

  “Let’s take it up a few more times. Maybe we’ll find a pattern for the arc fluctuations. Then we’d be able to find a flying method that avoids having it strike the fuselage,” the pilot who had been injured said, waving a bandaged arm. From his movements and expression, it was evident that his wounded hand hurt, but to show that he could still work the helicopter controls, he didn’t have it in a sling and was deliberately making large movements.

  “We can’t afford to have another accident. There needs to be a reliable guarantee of safety,” Lin Yun said.

  The other aviator said, “I’d like to ask you all to get one thing straight: We’re not taking risks for this project of yours. We’re doing it for ourselves. Army aviation needs new weapons now more than ever.”

  Lin Yun said, “Lieutenant, you misunderstand why we halted the experiment. We did so out of concern for the project. If we have another catastrophic crash like Lieutenant Wang Songlin’s, the project is over.”

  Colonel Xu said, “Let’s all use our brains. We’ve got to come up with workable safety measures.”

  An engineer said, “Can we consider using remote-controlled aircraft to conduct the experiment?”

  An aviator said, “The only craft capable of hovering and low-speed flight that has sufficient carrying capacity is a helium airship developed by Beihang University,† but it’s unclear whether it could be controlled precisely enough to guarantee discharge accuracy.”

  Lin Yun said, “And even if it could, it would only eliminate the risk of loss of life. It doesn’t help the experiment itself, since it would still be susceptible to a lightning strike.”

  I had a sudden thought. “My master’s advisor developed an anti-lightning paint for use on high-tension wires, but I’ve only heard people talk about it, so I’m not too familiar with the details.”

  “Your advisor was Zhang Bin?” Colonel Xu asked.

  I nodded. “Do you know him?”

  “I was one of his students. He was just a lecturer back then, and hadn’t transferred to your university.” Colonel Xu turned melancholy for a moment. “I called him up a few days ago. I’ve wanted to see him but I haven’t been able to find the time. I’m afraid he doesn’t have much time left. You know of his illness?”

  I nodded again.

  “He was rigorous in his studies, and he worked diligently his entire life....”

  “Let’s get back to the paint!” Lin Yun said impatiently.

  “I know of that invention. I was on the appraisal committee. It was remarkably effective in protecting against lightning,” Colonel Xu said.

  “The key thing is whether it needs to be grounded in order to work. If it does, then there’s not much point,” Lin Yun said. I had always admired her technical mind. The majority of anti-lightning paints needed to be grounded, but the question was not one a non-specialist was likely to ask.

  Colonel Xu scratched his head. “Hmm... it’s been so long that I can’t remember. You’ll have to ask the inventor for the details
.”

  Lin Yun snatched up the phone and passed it to me. “Give him a call at once and ask him. If it’ll work, then have him come to Beijing. We’ll need to manufacture a batch of it immediately.”

  “He’s a cancer patient,” I said, looking at her awkwardly.

  Colonel Xu said, “It’s not a problem just to ask.”

  I took the receiver from Lin Yun’s hand. “I don’t know if he’s at home or at the hospital...,” I said, flipping open my address book. His home number was on the first page. I dialed, and then a weak voice sounded on the receiver. “Who is it?”

  When I gave him my name, the distant voice instantly became stronger and more excited. “Oh, hello! Where are you? What are you up to?”

  “Professor Zhang, I’m working on a national defense project. How’s your health?”

  “You mean you’ve made progress?” he asked, ignoring my question.

  “It’s hard to say on the phone. How’s your health?”

  “Diminishing by the day. Zhao Yu visited. He may have mentioned it to you.”

  “Yes. How is your treatment going?” As I spoke, Lin Yun whispered urgently, “Ask him...,” but I covered the mouthpiece and snapped, “Get away.”

  When I returned the receiver to my ear, I heard Zhang Bin say, “...I’ve pulled together another set of research materials and I’m getting ready to send them to you.”

  “Professor Zhang, I’d like to ask you about something else. It’s about the high-tension wire anti-lightning paint you developed.”

  “Oh. That stuff had no economic value and was shelved long ago. What do you want to know?”

  “Does it need to be grounded?”

  “No. It doesn’t need grounding. Its shielding effect is self-contained.”

  “We want to use it on aircraft.”