Death's End

Green Glasses was similarly stunned. After a while, he managed to close his mouth and ask, carefully, “What kind of ‘God’ do you mean?”

“Just God.” That overwhelming sensation of exhaustion had returned. She had no patience to explain more.

“I don’t.”

Yang pointed to the large screens. “But the physical parameters governing the existence of life are utterly unforgiving. Take liquid water as an example: It can exist only within a narrow range of temperatures. Viewing the universe as a whole, this becomes even more apparent: If the parameters of the big bang had been different by even one million billionth, we would have no heavy elements and thus no life. Isn’t this clear evidence for intelligent design?”

Green Glasses shook his head. “I don’t know enough about the big bang to comment, but you’re wrong about the environment on Earth. The Earth gave birth to life, but life also changed the Earth. The current environment on our planet is the result of interactions between the two.” He grabbed the mouse and started clicking. “Let’s do a simulation.”

He brought up a configuration panel on one of the large screens, a window filled with dense fields of numbers. He unchecked a checkbox near the top, and all the fields became grayed out. “Let’s uncheck the option for ‘life’ and observe how the Earth would have evolved without it. I’ll adjust the simulation to be coarse-grained so as not to waste too much time in computation.”

Yang Dong glanced over at another terminal and saw that the supercomputer was operating at full capacity. A machine like that consumed as much electricity as a small city, but she didn’t tell Green Glasses to stop.

A newly formed planet appeared on the large screen. Its surface was still red-hot, like a piece of charcoal fresh out of the furnace. Time passed at the rate of geological eras, and the planet gradually cooled. The color and patterns on the surface slowly shifted in a hypnotic manner. A few minutes later, an orange planet appeared on the screen, indicating the end of the simulation run.

“The computations were done at the coarsest level; to do it with more precision would require over a month.” Green Glasses moved the mouse and zoomed in on the surface of the planet. The view swept over a broad desert, over a cluster of strangely shaped, towering mountain peaks, over a circular depression like an impact crater.

“What are we looking at?” Yang Dong asked.

“Earth. Without life, this is what the surface of the planet would look like now.”

“But… where are the oceans?”

“There are no oceans. No rivers either. The entire surface is dry.”

“You’re saying that without life, liquid water would not exist on Earth?”

“The reality would probably be even more shocking. Remember, this is only a coarse simulation, but at least you can see how much of an impact life had in the present state of the Earth.”

“But—”

“Do you think life is nothing but a fragile, thin, soft shell clinging to the surface of this planet?”

“Isn’t it?”

“Only if you neglect the power of time. If a colony of ants continue to move clods the size of grains of rice, they could remove all of Mount Tai in a billion years. As long as you give it enough time, life is stronger than metal and stone, more powerful than typhoons and volcanoes.”

“But the formation of mountains depends on geologic forces!”

“Not necessarily. Life may not be able to uplift mountains, but it can change the distribution of mountain ranges. Let’s say there are three mountains, two of which are covered by vegetation. The one that is nude would soon be flattened by erosion. ‘Soon’ here means on the order of millions of years, a blink of an eye in geological terms.”

“Then how did the oceans disappear?”

“We’d have to examine the records of the simulation, which would be a lot of work. However, I can give you an educated guess: plants, animals, and bacteria all have had important roles in the present composition of our atmosphere. Without life, the atmosphere would be very different. It’s possible that such an atmosphere would not be able to shield the surface of the Earth against solar winds and ultraviolet rays, and the oceans would evaporate. Soon, greenhouse effects would turn the Earth’s atmosphere into a copy of Venus’s, and then water vapor would be lost to space over time. After several billion years, the Earth would be dry.”

Yang Dong said no more as she stared at that yellow husk of a planet.

“Thus, the Earth that we live on now is a home constructed by life for itself. It has nothing to do with God.” Green Glasses held out his arms in mock embrace of the large screen, clearly pleased with his own oration.

Yang Dong was not really in the mood to discuss such matters, but the moment Green Glasses unchecked the option for life in the configuration panel, a thought had flashed into her mind.

She asked the next terrifying question: “What about the universe?”

“The universe?”