The oasis five kilometers away is not long in coming. Pen "Fun" Pavilion www.biquge.info

The road was desolate and lifeless, and it was not until they reached the edge of the oasis that they gradually began to perceive some breath of life.

Wherever the Quanyue rover passed, there were occasionally tiny strange plants peeking out of the cracks in the gravel.

"Alien plants, alien life! It's incredible!! Smith sighed as he pointed in the direction.

Yuan Haochen also looked around, but he didn't express his opinion, as if he was thinking about something.

"The ecosystem that Sand Star is currently showing is too monotonous, which is not scientific." Yuan Haochen thought to himself in his heart.

"Crunch~" sound.

The Izumitsuki spacecar stopped at the outer edge of the oasis, but the two of them didn't get out of the car in a hurry.

"First, use ultrasound and infrared detectors to check the surrounding environment to see if there are any unusual creatures." Hara explained to Smith with a serious face, and at the same time, he himself began to check the air conditions around him.

"The oxygen content here will be a bit higher than in the gravel pile area, up to 15 percent, which should be related to the plants in the oasis." Yuan Haochen sighed while looking at the test values, "I can't imagine that there are plants that can photosynthesize in the alien land, and life on Earth is really related to Alpha Centauri." ”

Yuan Haochen believes that if it were not for the intervention of the creator, perhaps in the long years to come, life could also be born on the earth, but the life forms born at that time must be different from the current earth, and presumably the intelligent beings who will eventually dominate the earth's civilization will not be humans.

"Although no toxic substances or unknown microorganisms were found in the air just now, the environment here is very different, so we still have to be cautious." After confirming that the atmosphere did not contain toxic gases or harmful microorganisms, Yuan Haochen felt a little more at ease.

"We should indeed be careful, although we humans have super immunity, it is always inappropriate to waste medicine because of some small things." Smith said with a slight self-deprecation.

"I don't know if that's good news or bad news." Smith said with a playful look at the results of the ultrasound and infrared detector examinations.

"Looks like you didn't find any obvious life in the oasis." Yuan Haochen said something that broke through Smith's meaning.

"Smith, are you disappointed?" Lynn on the Future joins their conversation via a satellite instant messaging system.

"While I was looking forward to seeing alien animals, I was also a little worried about seeing a Tyrannosaurus rex-like behemoth in the oasis." After Smith finished speaking, he smiled and asked, "By the way, do you think there will be giant creatures like dinosaurs on Sand Star?" ”

"It's impossible!" Yuan Haochen replied firmly while conducting the second atmospheric test.

"Oh?" Smith looked at him suspiciously.

"If you take a closer look at the plants in the oasis, what are the characteristics?" Yuan Haochen asked rhetorically.

"What are the characteristics?" Smith squinted and looked earnestly through the car window.

"Do you mean they're short?" Smith quickly spotted the signs of a problem.

"Not bad." Yuan Haochen nodded, "Do you know why?" ”

"Because of the low oxygen content." Lynn replied.

"And the effect of gravity." Yuan Haochen added.

"You two are simply encyclopedias, explain them to me in detail." Smith said with interest.

"When confronted with an unknown creature, their appearance is definitely the first thing we will pay attention to. For example, tall, short, fat and thin. "The atmospheric detection is not over yet, and idleness is idle, and Yuan Haochen happened to explain the reason for the inference to Smith.

"Galileo was a famous physicist, but one of his theories had great significance in the field of biology. In 1638, Galileo Galilei published a paper entitled "On the Dialogue of Two New Sciences and the Proof of Mathematics", in which he proposed the famous square-cube law, which states that when an object has undergone a proportional increase in size, its volume grows in a cubic shape and its surface area increases in a square manner. ”

That's right, this law seems very simple, and it is something that elementary school students know. But its impact on the size of the organism cannot be ignored. For example, on Earth, because of gravity, all of our weight is pressed on bones, but as our height increases, the cross-sectional area of our bones increases by squares, and the volume (or weight) increases by cubic numbers. ”

"In addition, the tall body needs more strength from the heart to send blood to the top of the head, but the area of the blood vessels has only increased by square times, so the toughness of the blood vessels will be greatly challenged. In short, because of the "square-cube" law, we can speculate that on any planet, there is an upper limit to the height of living things. ”

"However, there have been animals as tall as dinosaurs on Earth." Smith had a question in mind.

"Yes, but after the extinction of the dinosaurs, why didn't any land animal grow as tall as a dinosaur for so many years?" Yuan Haochen asked rhetorically.

"Does it have anything to do with the oxygen level?" Smith's eyes lit up, and he immediately grasped the crux of the matter.

"Many biologists agree that large size has great evolutionary advantages, such as being less likely to be prey to other species and having an advantage over similar competitors when mating, just as elephants are now less prey to other predators, and larger elephants have an advantage in mating. Moreover, larger organisms have a slower metabolic rate and a longer lifespan. ”

"There is a saying in China that goes like this: it is difficult for a good woman to cook without rice! The evolution of life is inseparable from the environment, in the era of dinosaurs, the oxygen content in the air is much higher than the current earth, and the higher oxygen content is also conducive to the growth of plants, which provides more adequate food for dinosaurs. All of these conditions allowed dinosaurs to evolve very large bodies, so elephants in the current environment of the earth could not grow as big as sauropods anyway. ”

"I see." Smith nodded brightly, as if he had learned something new.

"For life on other planets, evolution is also inseparable from the constraints of the environment, more resources, less gravitational pull have the opportunity to make life bigger. You see that Sand Star is such a barren environment, such a low oxygen content in the atmosphere, and a high level of gravity, these factors are not conducive to the growth and evolution of large organisms. ”

Yuan Haochen finally added.

"You say, will there be intelligent beings on the Sand Star?" Smith asked after a moment's thought.

"It's possible, but we haven't found anything yet, maybe they're hiding a lot."

"Will they hide in the deeper waters?"

"Then let's go see the lake in the oasis later."

A quarter of an hour later.

"Okay, the atmosphere is well monitored, there are no toxic substances and harmful microorganisms, get off." Yuan Haochen took the lead in opening the car door and walked down with some exquisite testing instruments.

Smith picked up two large-caliber pistols, threw one to Hara, and then hung a machete around his waist before stepping out of the space car.

(To be continued.) )