Galaxies have a history of more than 10 billion years. Our solar system is about 4.6 billion years old, and earth life has been around for more than 3 billion years. The earliest ancestors of human beings can be traced back to 3 million years ago. In terms of time span, compared with the age of galaxies, human beings only exist for a moment.
The first human ancestor who looked up at the starry sky actually indicated the arrival of human civilization – because we humans are curious creatures, and we know how to use our brain better. Therefore, we stand out from many creatures on the earth. After tens of thousands of years, we have been at the top of the earth’s food chain and become the master of this small blue planet.
Although we have the ability to rule the earth, but after all, only a few thousand years of civilization, is not enough to make human complacency. As a matter of fact, we human beings can’t explain exactly how we came from; even the specific structure of the earth under our feet can’t give an accurate answer Including most of the space threats in the universe, human beings can not resist them at present.
And it is very likely that there is not only one human civilization in the universe, or even “absolutely more than one human civilization”. According to the calculation of Drake equation, although the probability of civilization in the universe is almost zero, the probability of extraterrestrial civilization in the universe is as high as more than 90% at almost innumerable huge space-time scales. Even in the galaxy where our earth is located, there may be other civilizations, but human beings have not yet discovered them.
Therefore, some people have come up with a bold idea: is there a possibility that a fierce star war is going on deep in the galaxy, and we humans do not know it? It’s a possibility, but it’s not just one or two people. From Liu Cixin’s short science fiction “country teacher”, we can see the “carbon based Federation” and “silicon-based Empire” of the galaxy. These two civilizations are at war in the galaxy, and our earth is just a remote corner of the battlefield, which is almost destroyed by “accidental injury”.
Although it sounds cruel, in reality, alien civilization does exist and has made more progress than human civilization. If some innocent alien civilization visits the earth in the future, then we human beings will no longer have any illusions: as long as they can travel through the universe and come to our earth, they will be more advanced than our civilization.
Weak flesh has always been the fairest law, and in general it is the same in the universe. This includes Liu Cixin’s “dark forest law”, which is actually very correct. Therefore, for human beings, we need to constantly develop our own scientific and technological level to reach a higher level of civilization, so that we can have enough strength to talk with other alien civilizations.