"earth"

The energy released by the sun's nuclear fusion reaction, in addition to making the sun shine and heat, there is an important role, that is, to resist its own gravity

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

The earth's water resistance comes from the high temperature, pressure and density of its interior

The modern Earth's atmosphere is so rich in oxygen that the vast majority of this hydrogen will be re-oxidized to water without escaping from the Earth's top atmosphere

It is proposed that birds originated from dinosaurs, and that "ancestor birds" are a transitional species between birds and dinosaurs.

During the long evolutionary journey, the brain capacity and the complexity of the nervous system of primates have been increasing, and correspondingly, their intelligence has become higher and higher as a result

Earth is the only home we have in the universe and the only planet we know of so far that has life on it, and because of this, we usually think of it as a perfect planet.

In orbit for longer and longer periods of time, we need to solve not only inorganic resupply problems such as food, water, oxygen and propellant, but also the various problems faced by astronauts flying in orbit for long periods of time

If humans evolved from the forest archaeopteryx, how did the forest archaeopteryx emerge?

It has been billions of years since life appeared on earth, and although there are seven planets in our solar system in addition to earth, as well as a number of dwarf planets, moons and other relatively large bodies, so far we have not found alien life on any other planet in our solar system for the time being. Even mars, another earth-like planet in the habitable zone of our solar system, has not found a single sign of life. Could it be that life on earth is really unique and no other planet is allowed to have life?