Maby dark matter is the after birth of matter? Similar to cracking an egg in half and emptying the contents into a bowl. Then put the egg shell back together. The volume inside the egg shell would represent dark matter and the eggs contents it's self would represent matter. From their the egg (matter) can take manny forms to change its volume up or down. From fluffing the eggs up to being bigger than the egg shell it originated in, to cooking them down to fine powder or dencly packed balls of rock hard dirt and gasses.