Science

The "four great beasts" of physics actually exist only in thought experiments, and their proposal helps to develop and improve the relevant theories

Earthquakes are a common natural phenomenon. On average, millions of earthquakes occur on Earth every year, except that most of them are so mild that they are largely imperceptible to humans.

If mankind can master the method of extracting uranium from seawater in large quantities in the future, there will be enough uranium on the earth to last for tens of thousands of years, even hundreds of thousands of years!

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

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

The law of conservation of momentum means that the total momentum of a system remains constant when it is not subject to external forces or when the sum of the vectors of external forces is zero

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?

Earthquakes are a natural phenomenon known to all of us, and they are not unique to the earth. In theory, any planet with a solid crust can have an 'earthquake', and for the sake of distinction, we can call it a 'starquake'. The strength of a 'starshock' varies from planet to planet, so how terrible is the strongest known 'starshock'?

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

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