Compared to any other river system that Xiao Yu had visited before, the Maffei One Galaxy had one obvious feature, that is, the number of unusually large stars. This means that the Maffei One galaxy has a large amount of gas and dust clouds until now, and has been active for a long time.

This is a very obvious thing, the lifespan of giant stars is relatively short, if you want to maintain a large number of giant stars for a long time, then there must be a steady stream of giant stars to form continuously, and the continuous formation of giant stars must have enough interstellar dust cloud content as support.

To be active means to be unstable, and instability happens to be the natural enemy of intelligent life. After the civilization level is high to a certain level, civilization will have a certain ability to resist risks, such as primitive humans, a major earthquake can make civilization extinct, and now Xiao Yu, the destruction of a river system can not hurt him, Xiao Yu can escape in advance before the destruction of the river system.

"Maybe the Maffei One Galaxy is a dead galaxy." Xiao Yu thought secretly.

The Maffei One Galaxy is just a foothold in Xiao Yu's long journey, and Xiao Yu's next target is the Flying Kite Galaxy, which is the core of the entire Virgo Supercluster. The Flying Kite Galaxy is too big, and a big one means that the civilization base is enough to meet enough civilizations there, and communicate with them, and once again improve his scientific and technological development.

Faced with frequent and active stellar activity, Xiao Yu stepped into this completely unfamiliar river system.

"Perhaps, it is precisely because of the collision of the river system that Maffei has such a large number of interstellar dust clouds. Compared with billions of years ago, the intensity of the river system has decreased considerably. In the early days of the river system collision, it was likely to be a starburst galaxy. Xiao Yu thought secretly, and slowly moved towards the center of the river system.

In the process of continuous progress. A large number of river-level detectors were distributed. These detectors have perfect self-healing and self-recharging, as well as self-preservation abilities based on Level 7 civilization technology, they are Xiao Yu's eyes, and they can allow Xiao Yu's eyes to spread throughout the river system.

By the time Xiao Yu's main fleet reached the core of the river system, the detection range of these probes had already spread to half of the river system. In the long journey of the previous seven thousand years, because of the scientific and technological supplement of the microscopic civilization, Xiao Yu's technology has once again made great progress, so Xiao Yu can now have such the ability to detect a river system in detail.

But the results of the probe disappointed Xiao Yu. Under large-scale detection. Not to mention a smart civilization, Xiao Yu didn't even discover an ordinary life planet. The Mafei galaxy presented in front of Xiao Yu is active. But it was a desolate and dead place. There are no intelligent creatures here, just stars that are constantly dying and disillusioned, and here they are slowly evolving according to the laws of nature in the underworld.

"The stellar activity here is too active, and the short-lived giant stars scattered throughout the river system may be the killers who destroy the seeds of civilization. A supernova explosion of a giant star can indiscriminately destroy the seeds of living organisms within a radius of at least a few hundred light-years. It's like spraying insecticide in the Maffei system. Even if there were germinations of life, they would have been killed by this high-intensity insecticide long ago. Xiao Yu thought with some sighs.

The birth of life is a very demanding process of natural selection. In the age of Earth, it was common for scientists to question the search criteria for extraterrestrial life, such as: "Why does extraterrestrial life necessarily need water?" Life on Earth needs water, so does extraterrestrial life need water? Why does life have to exist on planets? Life on Earth needs the right temperature to survive, so does extraterrestrial life need this temperature as well? ”

According to this standard, it seems that life is not so demanding about the environment, and different environments will give birth to different lives. Just like the Maffei galaxy at this moment, there should also be creatures that adapt to the environment here.

But the truth tells Xiao Yu. This is wrong.

It's not that extraterrestrial life necessarily needs water, but that life is born on a premise that it is long-term, stable, and has some kind of protective environment. There must be no objection to the fact that newborn life is very fragile, so they must need some kind of protective device that can allow them to develop slowly, and exchange long hours for their ability to gradually adapt to their environment.

And the cosmic environment is very sinister, not to mention asteroid impacts, supernova explosions, high-intensity radiation areas after the death of stars, etc., such things abound in the universe, even if all these threats are not there, then there is also the threat of the main star around their own planet, you must know that the star is not a stable thing, when it transmits light and heat, it will also transport a large number of harmful rays, maybe these rays should not be called a harmful name, but they are unstable, And the newborn life cannot afford any instability.

Infrared, X-ray, visible light, gamma rays, these four types of light radiation, as well as neutrinos, beta decay and many other radiations, only visible light is the most stable. Therefore, it is inevitable that life has evolved to adapt to visible light, and if it adapts to visible light, the rest of the radiation is harmful.

This requires water, an atmosphere, and magnetic fields to protect life. Why water? Because water is a very common substance in the universe, hydrogen is common, oxygen is also common, so water is common, so water is a common indicator of searching for extraterrestrial life, rather than other liquid substances, such as methane.

It's not that liquid methane doesn't protect life, it's that methane is more complex than water, it's rarer than water. In terms of probability, it is more reasonable to use water as a search indicator.

Gaseous water is too active and thin, and solid water loses its basic fluidity, so it will inevitably be liquid water that can support the existence of life. This puts a demand on the temperature of the environment, because it is obvious that if the planet is too cold, the water will freeze, and if it is too high, the water will transpirp. There is a requirement for temperature, and there is a requirement for the distance of the planet from the star, and at the same time. There are also requirements for the intensity of the star's activity - for example, the activity of the newborn star is too strong, and the radiation is too strong, so the probability of life around it is low. For example, the aging red giant star is too big and too unstable, so there is generally no life around it.

For example, you can't be in too many asteroids, and asteroid impacts can have devastating effects on nascent life, which incidentally raises a secondary requirement - preferably with a few giant gas planets on the outer side of the planet. Because these gaseous planets can provide perfect protection for the living planet inside, it is best to have a relatively large moon that provides the last layer of protection for it. It can also cause tidal waves, causing the exchange of matter on the planets......

In fact, there is only one condition for the birth of life, and that is stability. Liquid water, on the other hand, is the best description of stability.

So. The Mafei galaxy that appeared in front of Xiao Yu at this moment. Life did not evolve.

"Perhaps, before the collision and fusion of galaxies, there was life in the Maffei One Galaxy, but that age was too long, and those lives may have died out long ago. It's been too long for even the ruins to be preserved. Xiao Yu sighed secretly in his heart.

The vicissitudes of time. Hundreds of millions, billions of years have passed in a hurry. The originally lively galaxy is dead, the originally desolate galaxy is prosperous, and the newborn star finally explodes into dust, and the dust condenses again to become the next generation of stars...... Everything is slowly evolving under the manipulation of the invisible hand of time.

With this exclamation, Xiao Yu's main fleet came to the core of the river system and visited the central black hole of the Mafei One galaxy. Compared to the Milky Way, the mass of the central black hole in Maffei I is much lower, about 300,000 times the mass of the sun. Its black hole activity has also all but ceased, and although the Maffei galaxy contains a large cloud of gas and dust, these things have not become its food.

It's an ancient beast that is sleeping.

Xiao Yu didn't try to disturb its peaceful sleep, Xiao Yu's fleet quietly bypassed it and continued to move forward. But at this time, Xiao Yu once again made a new discovery.

There was an amazing thing presented in front of Xiao Yu, it was a palace - although its appearance was different from any palace that Xiao Yu understood, but except for the name of the palace, Xiao Yu really didn't know what to call it.

It has obvious features of technological creation, such as a sleek exterior, precise geometry, things that are clearly artificial light sources, and ships that are orbiting and flying......

After Xiao Yu thought that the Mafei Galaxy was just a dead and silent river system, and was disappointed in this river system, this palace was unexpectedly presented in front of Xiao Yu, leaving Xiao Yu dumbfounded.

A desolate, simple, atmospheric, vast, advanced, and powerful aura rushed towards Xiao Yu. It seems that no words of praise are enough to describe the greatness of this palace. This is not an illusory word, just one aspect of this is enough to make Xiao Yu sigh like this.

It's too big, too big to imagine. The largest battleship Xiao Yu had ever made, the stellar class battleship, was as small as dust in front of it. Even a massive star is nothing in front of it.

The size of this palace is calculated in light years. (To be continued......)

PS: Rainbow just wants to do its best to present a rainbow imaginary universe in front of everyone, whether it is a description of that fifth-level civilization, or about various technologies, various astronomical phenomena, or for certain events, such as the description of the birth of life in this chapter, etc., they are all working towards this goal. This is the original intention of the rainbow, and the upgrade of the protagonist is just to have a broader stage and vision, and compared with the original intention of the rainbow, it is secondary. Said that the rainbow was in the water, and the rainbow was recognized.

This is what Rainbow has always insisted on, and Rainbow is like that, and Rainbow has no intention of changing it in the foreseeable future. Although the battleship will have better results if it is written in a more cheerful style, it will also lose its character and will not be visible to the public. This is unacceptable to the rainbow.

If you just want to see the refreshing plot such as the protagonist killing all directions, and are not interested in the description of various astronomical events and thinking about the universe, you can take a look at other books to spice it up.