Li Changzhou flipped through the popular science book he had just brought back from Earth, while the more advanced books were with Yang Qinglan.
In the universe, naturally, one reads about cosmology.
For ease of understanding, the book compared gravity to a slope—anything that exists causes a depression in the universe, and this depression creates an invisible yet smooth slope.
The slope points in all directions, up, down, left, and right; any substance that enters the slope will roll down it, and this is gravity.
The Milky Way, where Earth is located, is actually a black hole with a mass exceeding that of three million constant stars, capturing substances among which stars alone exceed three hundred billion.
As for small asteroids like Earth, they simply can't be counted.
Only one sentence piqued Li Changzhou's interest: even light is subject to gravity.
