"universe"

The mass of a star cannot grow indefinitely, it can only reach the "Eddington limit" at most, so beyond this threshold, it will soon "eject" the extra material

If we make the space station in space into a ring and let it rotate, then the humans in it will also feel the "centrifugal force" to "push" themselves towards the outer wall of the space station

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 theory, when a civilization develops into a civilization that can cross the stars, there is basically no risk of extinction

Scientists using modern observation equipment have determined the size, position, distance and other data of most of the objects in our galaxy

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.

In the past days, scientists have been working on the study of meteorites, and as the research continues, there is more and more evidence that life should originate from outer space

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

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

NASA's Jet Propulsion Laboratory's Near Earth Object Research Center has such a database, which is called the "Fireball Database."