Harvard scientists: 10 billion years ago, the universe is full of life

On a clear night, when looking up at the bright diamond-like stars, I believe I am not the only one who has thought: at this moment, are there "people" on those stars looking up at the stars? And they are not also have the same feelings?

In fact, ordinary people can think of the problem, scientists of course can also be able to think. In the scientists' view, if we can confirm that there is intelligent life in the universe other than human beings, then not only solved the long-standing doubts in the mind, the development of civilization is also a very beneficial thing.

The development of human beings has always been in the dark groping forward, no guidance and no clear direction, and once the existence of other civilizations is confirmed, we will have the direction to move forward, the development speed will also be greatly increased.

Even if they do not yet have our high level of technology, but at least have the ability to communicate with each other's companions, which is much stronger than their own closed door is bound to be much stronger.

However, the ideal is rich, the reality is bone, the magnificent and gorgeous universe is a dead silence, there is no trace of any alien civilization activities, do they not exist? With Carl Sagan once said a sentence to answer: the universe is so big, if only human existence, it is really too wasteful.

Therefore, the current mainstream view of the scientific community that the probability of the existence of extraterrestrial intelligent life is extremely high, and it is really only a matter of time before humans and they meet.

The earliest civilization in the universe was born how many years ago?

However, even if no trace of them can be found in the universe, it can still hinder human fantasies about them. In science fiction works, aliens and extraterrestrial civilizations abound as clues or backgrounds.

When we are immersed in the exaggerated brains and grand scenes of these science fiction works, a question must arise in someone's mind: if there are other civilizations in the universe, how long will they be born before human civilization? To solve this doubt, we must first know the history of the development of the universe's stars.

The earliest civilizations in the universe

According to the accepted conclusion of the scientific community, 500 million years after the birth of the universe, the first generation of stars appeared quietly in the universe. Unlike most stars today, the generation of stars are all very high quality blue giants.

Although there are stars, but at this time the universe is very single element, can not form solid planets, let alone more complex and delicate life.

In addition, blue giants are also very "short-lived", usually only tens of millions of years, which also limits the emergence and development of complex life.

When the first generation of stars died out, thanks to their supernova explosion of various elements, the universe began to become rich and colorful, the second generation of stars, planets in their remains, and the possibility of life, because the composition of the elements of life complete.

To run through the timeline, 500 million years after the birth of the universe, the first stars appeared, and tens of millions of years later the first stars died out, and the second generation of stars and planets began to appear.

If the evolutionary process of human beings and the evolution of the Earth are typical, then the earliest extraterrestrial civilizations in the universe would have reached the current level of human beings 5 billion years later, when only 5.5 billion years have passed since the Big Bang.

Combined with the time of human emergence, we are able to conclude that the earliest extraterrestrial civilization in the universe, theoretically, would have emerged 8 billion years earlier than us.

What would a civilization 8 billion years ahead of us look like? I'm afraid any brain can't imagine their existence, because it's just too far away from us, after all, humans are just a tender civilization without any guidance, without any direction, and with a development time of just less than 10,000 years.

The time when the earliest life in the universe appeared

The article here may be a doubt in the minds of many people: several hundred million years after the birth of the universe, it will be able to appear life? The answer is yes, there are even scientists believe that more than 10 billion years ago the universe is full of traces of life, when the universe is the real paradise of life.

Avi Loeb, director of astronomy at Harvard University, has published a paper called "The Habitable Age of the Early Universe". That's right, the same scientist who until 2021 insisted that the Oromo was an extraterrestrial probe.

In his paper, he pointed out that from 10 million years after the birth of the universe until 10 billion years ago, the temperature of the cosmic microwave background radiation dropped from 100°C to 0°C, which made the planets, no matter how far away from the stars, their surface temperatures were able to allow liquid water to remain and behave in a habitable nature.

After further analysis of various data, Avi Loeb proposed that even after the average temperature of the universe fell to 0 ℃ around 10 billion years, because the planets will radiate heat from the interior, the planet can still remain habitable for a long time, so the earliest life in the universe may have appeared more than 10 billion years ago.

Were there planets in the early universe?

As mentioned earlier, in the pre-creation of the universe, solid planets could not form at all because the elements were relatively homogeneous, with only two elements, hydrogen and oxygen (and very small amounts of beryllium and lithium).

But this was only before the first generation of stars had a supernova explosion. Once they had a supernova explosion, rocky planets became possible, so it is entirely possible that the universe had rocky planets at a very early stage.

This conclusion raises a lot of thoughtful possibilities

If life in the universe first appeared 10 billion years ago, and the oldest civilizations appeared 8 billion years ago, why is there no trace of their existence in the universe?

You know, even if the scale of distance in the universe is the biggest obstacle to the expansion of civilization, but in a much larger volume of time scale, certainly have long been able to overcome the obstacle of distance, to achieve the colonial rule of a large galaxy.

After all, according to the conjecture of the von Neumann machine, as long as it can create a robot that can create itself, then it is completely capable of achieving full coverage of the galaxy within 100 million years.

So, if Avi Loeb's view is not in question, then there are only two possibilities that could explain this bizarre reality.

The first possibility, they haven't reached the Milky Way and its surrounding galaxies yet, so we haven't found any traces of them.

The second possibility is that they have already colonized the galaxy, but because we have been living in it, we have already taken some "unusual" as "unusual", so we have not found any traces of them.

In fact, from the human point of view, we certainly do not want the second possibility is true, after all, no one wants to be muddled, and no one wants to be a self-paralyzed clown.