C249 Debris

"Our Milky Way Galaxy has about 400 billion stars …" I looked up at the stars in the sky and started to talk, "And in the entire universe, there are roughly a corresponding number of galaxies. That is to say, the number of stars in the universe is about 400 billion times 400 billion, which is about 22 out of 10... And our earth only has about 10 to 18 cubic meters of sand