Cixin Liu - The Three-Body Problem

Ye clearly remembered the two dates noted in the paper. During those windows, the Red Coast monitoring system had also received strong interference from solar outages. She checked the operations diary and confirmed her memory. The times were close, but the solar outages had occurred sixteen minutes and forty-two seconds after the arrival of the Jovian radio outbursts on Earth.

The sixteen minutes and forty-two seconds are critical! Ye tried to calm her wild heartbeat, and asked the librarian to contact the National Observatory to obtain the ephemeris of the Earth’s and Jupiter’s positions during those two time periods.

She drew a big triangle on the blackboard with the sun, the Earth, and Jupiter at the vertices. She marked the distances along the three edges, and wrote down the two arrival times next to the Earth. From the distance between the Earth and Jupiter it was easy to figure out the time it took for the radio outbursts to travel between the two. Then she calculated the time it would take the radio outbursts to go from Jupiter to the sun, and then from the sun to the Earth. The difference between the two was exactly sixteen minutes and forty-two seconds.

Ye referred to her solar structure mathematical model and tried to find a theoretical explanation. Her eyes were drawn to her description of what she called “energy mirrors” within the solar radiation zone.

Energy produced by reaction within the solar core is initially in the form of high-energy gamma rays. The radiation zone, the region of the sun’s interior that surrounds the core, absorbs these high-energy photons and re-emits them at a slightly lower energy level. After a long period of successive absorption and re-emission (a photon might take a thousand years to leave the sun), gamma rays become x-rays, extreme ultraviolet, ultraviolet, then eventually turn into visible light and other forms of radiation.

Such were the known facts about the sun. But Ye’s model led to a new result: As solar radiation dropped through these different frequencies on its way through the radiation zone, there were boundaries between the subzones for each type of radiation. As energy crossed each boundary, the radiation frequency stepped down a grade sharply. This was different from the traditional view that the radiation frequency lowered gradually as energy passed from the core outwards. Her calculations showed that these boundaries would reflect radiation coming from the lower-frequency side, which was why she named the boundaries “energy mirrors.”

Ye had carefully studied these membranelike boundary surfaces suspended in the high-energy plasma ocean of the sun and discovered them to be full of wonderful properties. One of the most incredible characteristics she named “gain reflectivity.” However, the characteristic was so bizarre that it was hard to confirm, and even Ye herself didn’t quite believe it was real. It seemed more likely an artifact of some error in the dizzying, complex calculations.

But now, Ye made the first step in confirming her guess about the gain reflectivity of solar energy mirrors: The energy mirrors not only reflected radiation coming from the lower-frequency side, but amplified it. All the mysterious sudden fluctuations within narrow frequency bands that she had observed were in fact the result of other radiation coming from space being amplified after reflecting off an energy mirror in the sun. That was why there were no observable disturbances on the surface of the sun.

This time, after the Jovian radio outbursts reached the sun, they were re-emitted, as if by a mirror, after being amplified about a hundred million times. The Earth received both sets of emissions, before and after the amplification, separated by sixteen minutes and forty-two seconds.

The sun was an amplifier for radio waves.

However, there was a question: The sun must be receiving electromagnetic radiation from space every second, including radio waves emitted by the Earth. Why were only some of the waves amplified? The answer was simple: In addition to the selectivity of the energy mirrors for frequencies they would reflect, the main reason was the shielding effect of the solar convection zone. The endlessly boiling convection zone situated outside the radiation zone was the outermost liquid layer of the sun. The radio waves coming from space must first penetrate the convection zone to reach the energy mirrors in the radiation zone, where they would be amplified and reflected back out. This meant that in order to reach the energy mirrors, the waves would have to be more powerful than a threshold value. The vast majority of Earth-based radio sources could not cross this threshold, but the Jovian radio outburst did—

And Red Coast’s maximum transmission power also exceeded the threshold.

The problem with solar outages was not resolved, but another exciting possibility presented itself: Humans could use the sun as a superantenna, and, through it, broadcast radio waves to the universe. The radio waves would be sent with the power of the sun, hundreds of millions of times greater than the total usable transmission power on Earth.

Earth civilization had a way to transmit at the level of a Kardashev Type II civilization.

The next step was to compare the waveforms of the two Jovian radio outbursts with the waveforms of the solar outages received by Red Coast. If they matched, then her guess would receive further confirmation.

Ye made her request to the base leadership to contact Harry Peterson and obtain the waveform records of the two Jovian radio outbursts. This was not easy. It was difficult to find the right communication channels, and numerous bureaucracies required layers of formal paperwork. Any error could lead to her being suspected of acting as a foreign spy. So Ye had to wait.

But there was a more direct way to prove the hypothesis: Red Coast itself could transmit radio waves directly at the sun at a power level exceeding the threshold value.

Ye again made her request to the base leadership. But she didn’t dare to give her real reason—it was too fantastic, and she would have been turned down for certain. Instead, she explained that she wanted to do an experiment for her solar research: The Red Coast transmission system would be used as a solar exploration radar whose echoes could be analyzed to obtain some information about solar radiation. Lei and Yang both had deep technical backgrounds, and wouldn’t have been easily fooled, but the experiment described by Ye did have real precedents in Western solar research. In fact, her suggestion was technically easier than the radar exploration of terrestrial planets already being conducted.

“Ye Wenjie, you’re getting out of line,” said Commissar Lei. “Your research should be focused on theory. Do we really need to go to so much trouble?”

Ye begged, “Commissar, it’s possible that a big discovery will be made. Experiments are absolutely necessary. I just want to try it once, please?”

Chief Yang said, “Commissar Lei, maybe we should try once. It doesn’t seem to be too difficult operationally. Receiving the echoes after transmission would take—”

“Ten, fifteen minutes,” Lei said.

“Then Red Coast has just enough time to switch from transmission mode to monitoring mode.”

Lei shook his head again. “I know that it’s technically and operationally feasible. But you… eh, Chief Yang, you just lack the sensitivity for this kind of thing. You want to aim a superpowerful radio beam at the red sun. Have you thought about the political symbolism of such an experiment?” [32] Translator’s Note: Chairman Mao was often compared to the “red sun,” especially during the years of the Cultural Revolution.

Yang and Ye were both utterly stunned, but they did not think Lei’s objection ridiculous. Just the opposite: They were horrified that they themselves had not thought of it. During those years, finding political symbolism in everything had reached absurd levels. The research reports Ye turned in had to be carefully reviewed by Lei so that even technical terms related to the sun could be repeatedly revised to remove political risk. Terms like “sunspots” were forbidden. [33] Translator’s Note: The Chinese term for “sunspot” ( ) literally means “solar black spots.” Black, of course, was the color of counter-revolutionaries. An experiment that sent a powerful radio transmission at the sun could of course be interpreted in a thousand positive ways, but a single negative interpretation would be enough to bring political disaster on everyone. Lei’s reason for refusing to allow the experiment was truly unassailable.