"universe"

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

After the sun evolves into a red giant, the hydrogen in its core is almost completely fused into helium, so the nuclear fusion inside the sun stops, after which the sun loses its internal radiation pressure and continues to collapse, leading to a constant increase in temperature and pressure in its core, while the helium in the central region of the sun is gradually compressed into the condensed state.

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

It has long been discovered in practice that the phenomenon of "gravitational time dilation" does exist

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

Since gravity is actually a manifestation of gravity, and the magnitude of gravity is proportional to mass, for those objects with smaller masses, their own gravity is smaller

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.

A rigorous discussion of the unknown is not possible, so it is necessary to narrow down the universe we are discussing to only the universe we can see

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

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