Because of the speed of light. The known universe is about sixteen billion light-years across, and it’s still expanding. But the speed of light is on… - Liu Cixin

Because of the speed of light. The known universe is about sixteen billion light-years across, and it’s still expanding. But the speed of light is only three hundred thousand kilometers per second, a snail’s pace. This means that light can never go from one end of the universe to the other. Since nothing can move faster than the speed of light, it follows that no information and motive force can go from one end of the universe to the other. If the universe were a person, his neural signals couldn’t cover his entire body; his brain would not know of the existence of his limbs, and his limbs would not know of the existence of the brain. Isn’t that paraplegia? The image in my mind is even worse: The universe is but a corpse puffing up.

The past was like a handful of sand you thought you were squeezing tightly, but which had already run out through the cracks between your fingers. Memory was a river that had run dry long ago, leaving only scattered gravel in a lifeless riverbed. He had lived life always looking out for the next thing, and whenever he had gained, he had also lost, leaving him with little in the end.

The world described by modern physics has already moved far beyond our common sense and intuition, even beyond our imagination, and this is, of course, the richest resource for science fiction. I’ve tried to turn the magical world as demonstrated by modern physics into vivid stories. Most of my stories were based on and imagined along the lines of physics and cosmology.

I have a dream that one day brilliant sunlight will illuminate the dark forest