"Human"

If someone asks the question, are humans alone in the universe? I believe that most people would answer in the negative. In fact, the scientific community also generally agrees that there are a large number of intelligent civilisations in the vast universe, some of which may even be far ahead of our civilisation, and in order to better describe the technological level of intelligent civilisations in the universe, scientists have also proposed the concept of "Cosmic civilisation levels".

Compared to radio messages sent by humans, this method seems to be more suitable for intelligent civilizations to announce their presence in the universe, because this method belongs to the "broadcast" in space, and intelligent civilizations in all directions can be observed

In our solar system, there are 2 planets in the habitable zone of the solar system, one of which is our home planet Earth, and the other is Mars

How exactly did such a complex life emerge on Earth? This is a great mystery to modern humans, but we are almost certain that the "birth of life" is a process that has a very small probability of occurring.

Since humans and chimpanzees are reproductively isolated from each other and cannot bond, can we transfuse chimpanzee blood to us humans?

The existence of reproductive isolation, so that these situations can not occur, even if there are some individuals of different species sometimes complete the mating, but they generally can not produce offspring, or produce offspring can not continue to reproduce

Intelligent life is rare in the universe, or perhaps it is just wishful thinking on our part. As mentioned earlier, just in the galaxy, there are hundreds of millions of planets that have the natural conditions to nurture life, so a reasonable speculation is that life has evolved on many planets, and even a number of planets have evolved intelligent life.

When we humans feel very tired, we often say that we can fall asleep standing up, but this is just a description. In reality, it is impossible for humans to sleep standing up, but there are many animals in nature that have this such a skill that humans do not have, for example, horses can sleep standing up effortlessly.

Of all the known rocky planets in the solar system, the one with the most similar natural environment to Earth is Mars, and exploration data show that Mars also has an atmosphere, four seasons of the year, and even a rotation period similar to that of Earth.