Theft of Hawking's Livelihood (Part Two)

"."

After hearing Xu Yun's idea about two black holes merging,

Yang Zhenning didn't answer again. Instead, all that came through the phone was the scratch of calculations on paper.

The idea had shifted from dropping a small ball into a black hole to merging two black holes.

The two were similar in terms of [behavior]: in both cases, two things came together and became one. But their significance was entirely different.

The former was like a heterosexual relationship, which was at least somewhat common. The latter was basically like a gay couple.

If a small ball falling into a black hole caused entropy to increase because of its radius, then theoretically, the same should be true when two black holes merged.

In other words,

the black hole's surface area and its entropy would both increase irreversibly as a result.

"."

This time,

Yang Zhenning spent a full twenty minutes on his calculations. During that time, no conversation came from inside the room, and even Lu Guangda, waiting outside, couldn't help opening the door a crack to sneak a look.

Twenty minutes later,

a complicated sigh came softly through the receiver Xu Yun held:

"Just as I thought. In a rotating merger, the area of the black hole's event horizon increases with its mass."

"Little Xu, you're right."

Yang Zhenning didn't sound dejected, but he was deeply moved.

Physicists had yet to witness black holes merging—in fact, they hadn't even observed an ordinary black hole.

Still, anyone with a bit of sense could imagine that a black hole merger wouldn't be instantaneous—at least, not from an observer's perspective.

If the two black holes were not aligned, they would first rotate before lining up. This process could take millions of years, or even longer.

So, just as with a small ball