"universe"

The energy released by nuclear fusion is actually an important basis for stars to be able to maintain their stability

Between the Earth and the Moon there exists a much more empty space than imagined, so what can be put down in this space?

For humans, the universe is too dimensional for us to see the details of its depths for the time being

Proxima, a slightly smaller red dwarf than Ross 508, has been frequently observed by astronomers as a giant flare in the past.

Everything we can see in the universe has an internal structure and they are all made up of smaller matter, so what is the smallest matter in the universe?

Although the Earth is just a "grain of dust suspended in the sun" in the universe, for us humans, this "grain of dust" is irreplaceable.

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".

Below the solar system, there is a star system labeled "alpha Centauri".

The reason we don't see time travelers is actually because they are not in our timeline

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