Some time had passed since the sunset.
Tang Yue and Tomcat were sitting on the vehicle’s rooftop, a star chart spread over their knees as they looked up at the sky.
However, today’s weather was rather gloomy. The sky wasn’t starry like usual and the atmosphere was emitting a turbid pale red glow, covering the sky in a seemingly thin veil. Tang Yue narrowed his eyes. “There are much fewer stars today than yesterday. There’s only a few hundred of them.”
“It’s not possible for Mars to always have clear skies, due to inclement weather.” Tomcat widened its eyelids with its paw and swept the sky with its round eyes.
“Can you see them?”
“Of course.” Tomcat turned its head over. “The average person can identify stars with magnitude five at the very least. Even if your vision is better than most people, your resolving power would at most be around magnitude six. That’s a biological limit of you humans. A human’s pupil doesn’t exceed eight millimeters in diameter, and it only allows 20 square millimeters of light in, but I’m different. I’m a cat.”
Tomcat’s pupils dilated like a camera lens.
“The eye structure of mammals are essentially identical to those of cameras and telescopes, but of course, the bigger the aperture, the stronger the resolving power.”
Tomcat seemed rather smug.
“Are you even considered a mammal?” Tang Yue mumbled.
Tomcat’s ears pricked up.
“How am I not one?” Tomcat corrected him. “When it comes to zoological taxonomy, I’m a vertebrate mammal, a carnivorous feline of the United Nations’s robotic cat subspecies.”
Tomcat and Tang Yue were determining their longitude using the two Martian moons, Phobos and Deimos. Phobos was rather striking in the clear night sky, with it being a tiny light blob that was about a sixth of the Moon’s size. In fact, its diameter was far smaller than the Moon. Phobos’s diameter was twenty-six kilometers. The reason it looked big was because of its low orbit. It was only six thousand kilometers from the Martian surface and was practically clinging to it in orbit. It circled Mars three times a sol.
As for Deimos, it looked no different from other stars. It was a dim speck of light. If its location wasn’t known ahead of time, the average person wouldn’t have been able to find it.
Not long ago, Deimos had suffered a collision, sending it off its original trajectory. The energy carried by Comet Tom-Tang-Mai I was astounding. Even a light brush was enough to send the tiny Deimos flying out. Its nearly circular orbit of 23,000 kilometers had now become a huge ellipse.
“Phobos is about to rise again.” Tomcat did a time check and pointed west.
Tang Yue looked in the direction of its paw and under the dark red sky, the blurry blob of light had already risen above the horizon.
Phobos didn’t have clear boundaries like the Moon. It was only a huge piece of rock over twenty kilometers in diameter with craters covering its entire surface. In Tomcat’s words, “It’s a potato that a rat has nibbled on.” This tiny piece of rock reflected very little of the sun’s light.
“Phobos is also very dim,” Tang Yue said. “This darn weather is like there’s a smog.”
“It’s a result of atmospheric activity. I once told you that the Martian atmosphere’s structure is completely different from Earth’s. There’s only a troposphere that’s dozens of kilometers high.” Tomcat looked up at the sky. “The wind can sweep the dust and sand high into the sky, then be swept around the globe at altitudes of forty kilometers above us. They could be moved to every corner of this planet.”
“How is it?” Tang Yue asked. “Are we on the right track?”
“We have deviated a little.”
“By how much?”
“Five arcminutes. It’s within expectations.” Tomcat straightened its arm and shifted slightly to the left. “Tomorrow morning, we should head slightly east when we set off.”
“Feel free to do so, you’re the navigator.” Tang Yue lazily leaned back onto the ground. “As long as we can accurately reach our destination, I don’t care if we deviate left or right. Don’t you find me very broadminded?”
“How would I know if you are broadminded or not?” Tomcat shrugged its shoulders. “If you’re broadminded, do it yourself. I believe you will go off course all the way to the north pole.”
“Magnanimous!” Tang Yue lay beside the cat, turning his head to shout at it.
Tomcat had the star chart covering its face as it leaned back. Propping its head up, it crossed its hindlegs.
Its ears twitched as the star chart rhythmically moved—Tomcat was humming a song, but it shook its ears instead of its legs.
“There’s another thirty kilometers tomorrow. Another thirty kilometers the sol after tomorrow,” Tang Yue said. “We should arrive on the third sol. These few sols seem to take an eternity.”
“But only the heavens know what’s awaiting us on the third sol.” Tomcat turned its head under the chart, revealing its shimmering eyes under the piece of paper. “You might know what’s awaiting us tomorrow and the sol after tomorrow, but you have no idea what’s waiting for us on the third sol. In three sols time, you might be motionless on the ground or have reached the ends of the Universe.”
Tang Yue was taken aback. It took him a few seconds to understand what Tomcat was saying.
He was unable to crack time and see the future. Three sols were actually no different from an infinitely distant future. In three sols, where would he be?
At his destination?
On Kunlun Station?
On Earth?
Or would he be in a particular solar system on a particular galactic arm of the Milky Way, or even a spot beyond the observable Universe?
Apart from the most probable first option, he could be any corner in the Universe.
No.
Was the first option really most probable?
Perhaps the probability of him being in any corner of the Universe was identical.
Tang Yue thought silently.
“What do you wish to say?” Tang Yue asked. “What’s really unknown is the future?”
“What’s really unknown is the future.”
Tang Yue fell silent and took out a pencil from his pocket. He raised it in midair. “Actually, we can predict the future. Just like this pencil. If I were to release it, it would immediately drop. By using Newton’s laws of motion, we can precisely predict its speed and state at any point in time.”
“Then if you release it, will it land on you?” Tomcat asked.
“Of course,” Tang Yue replied.
“Then release it.”
Tang Yue glanced at it, unsure what the point of carrying out the experiment. Any ordinary person could tell that the pencil would fall due to gravity if he released it.
He released his grip.
However, the pencil didn’t fall on Tang Yue’s body.
This was because Tomcat had reached out and grabbed it.
“We can only predict the future in a specific closed system. The unknown influences that come beyond the system are impossible to calculate. It’s just how using Newton’s laws of motion will not allow you to predict me suddenly grabbing it.” Tomcat waved the pencil. “Predictions need conditions. Conditions require drawing lines. And since a line is drawn, it means there is an interior and an exterior. This Universe’s exterior is forever an unknown. It can interfere with you and also not interfere with you. The best interference is that an advanced civilization’s spacecraft suddenly lands in front of us and the next second pulls you up to reach the other end of the Milky Way via a wormhole.”
“That’s just sophistry.” Tang Yue was at a loss for a comeback.
“But it adheres to logic.” Tomcat harrumphed.
Tang Yue looked at the dark red sky; his thoughts a mystery. The farthest he could see was the thin clouds twenty kilometers high. And above the clouds, the atmosphere was slowly stirring, carrying billions of tonnes of dust and sand as they began enveloping all of Mars.