What happens to matter overtime on planet earth and in the universe?

bones will become fossils because over time the pores fill with nutrients and other things and become solid. The reason space seems so empty is cause it's so big light travels at about 6 trillion miles a year and the universe is about 14 billion years old that means the universe is about 840,000,000,000,000,000,000,000 miles across so there is a lot of space between every thing plus the universe is expanding and getting bigger all the time so every thing is getting further away as time goes on.