Around twenty-four minutes into the flight, ball lightning was excited. The arc went out, and the feeler-equipped helicopter approached the thunderball to a distance of roughly twenty-five meters, then aligned the feeler. This was the first time a helicopter had been so close to the thunderball since the first one was excited. Tracking flight was difficult, because the thunderball was unaffected by air movement and no one knew what determined the path of its drift, which was volatile and random-seeming. Most dangerously, it might suddenly approach the helicopter. From recordings after the incident we discovered that the helicopter had drawn as close as sixteen meters to the thunderball. It was an ordinary thunderball that glowed orange yellow, and was inconspicuous in the daylight. It remained excited for one minute and thirty-five seconds before it disappeared, at a point 22.5 meters from the helicopter, with an explosion that Lin Yun and Captain Liu could hear clearly from inside. The feeler system triggered, and the twenty-odd-meter pole brought the tip of the superconducting lead to the precise point of disappearance. The recording showed that the time from the thunderball’s disappearance to the arrival of the lead was just 0.4 seconds.
That was immediately followed by a loud noise next to Lin Yun, as if something on the aircraft had exploded. The cabin quickly filled with scalding steam. But the helicopter maintained a normal flight attitude all the way back.
The helicopter landed amid cheers. Like Colonel Xu had said, in this experiment, a safe return was a victory.
Upon inspection, it was a bottle of spring water left under the seat by one of the ground crew that had exploded. The thunderball had released its energy into the water, turning it instantly to steam. Fortunately, since it was under the seat and ruptured without fragmenting, the only injury was a light burn to Lin Yun’s right calf where the steam had penetrated her combat uniform.
“We’re lucky the helicopter is oil-cooled. If it had a water tank like in a car, it would have turned into a bomb,” Captain Liu said with a shudder.
“You’re overlooking another, even bigger way you were lucky,” Ding Yi said, coming over with a mysterious smile, as if none of this had anything to do with him. “You’re forgetting that there was water on the helicopter apart from that bottle.”
“Where?” Lin Yun asked, but then answered immediately, “My God! Inside of us!”
“Yes. Your blood, too.”
We all took a chilly breath. The prospect of all the blood in their bodies turning to steam in the blink of an eye was too much to imagine.
“That means that when ball lightning selects a target to release its energy, the target’s boundary conditions are very important,” Ding Yi said thoughtfully.
Someone said, “Professor Ding, you ought to be thinking about thunderballs that have already released their energy. What were they called? Bubbles? There ought to be one in the battery.”
Ding Yi nodded. “The capture process was carried out with high precision. It ought to be in there.”
We all grew excited, and began to take the superconducting battery off the helicopter. There was more than a bit of irony in this excitement, since most people had already guessed what the outcome would be. The proceedings were a relaxing comedy to celebrate the helicopters’ safe return.
“Professor, when can you bring out the bubble and give us all a look?” someone asked after the heavy battery was finally out. We all expected that Ding Yi would secrete the battery in the lab so that as few people as possible would witness his failure, but his answer caught us by surprise: “Right away.”
Cheers sounded in the crowd, like we were a group of deviant onlookers awaiting a beheading.
Colonel Xu took a step up the ladder of one of the helicopters, and said loudly, “Listen up. Extracting the bubble from the battery requires care and full preparation. The battery will now be taken to Lab 3 and we will inform you of the results presently.”
“Colonel, everyone’s put in so much effort, particularly Captain Liu and Major Lin, who risked their lives. I think they have the right to be compensated,” Ding Yi said, to another chorus of cheers.
“Professor Ding, this is a significant experimental project, not a children’s game. I order the battery to be returned to the lab immediately,” Colonel Xu said firmly. I sensed his kindness, and knew he was doing his best to preserve Ding Yi’s dignity.
“Colonel, don’t forget that the bubble extraction portion of the experiment should be my sole responsibility. I have the right to decide what steps to take for this experiment and when to take them!” Ding Yi said to Colonel Xu.
“Professor, I suggest you calm down,” the colonel said to him quietly.
“And what’s Major Lin’s opinion?” Ding Yi asked the silent Lin Yun.
With a toss of her hair, she said decisively, “Do it now. Whatever it is, it’s better that we face it sooner rather than later.”