It may be that there aren't really any quantities which are constant in time in the universe. The quantity of matter is not constant, because matter can be created or destroyed. But we might say that the energy of the universe would be constant, because when you create matter, you need to use energy. And in a sense the energy of the universe is constant; it is a constant whose value is zero. The positive energy of the matter is exactly balanced by the negative energy of the gravitational field. So the universe can start off with zero energy and still create matter.

[ ARE YOU ANNOYED?] If so you are being annoyed by steven hawking verbatim.

In simple terms, if you dig a hole the volume of the stuff you remove from the hole equals the volume of the hole.

As Minkowki geometrically demonstrates there can be more time than space in spacetime, an imbalance can occur that leads to a overall phase shift.
Just as water can go from a plasma to steam to liquid to ice, a phase change of the universe tends toward entropy and a lower energy state.

[STILL ANNOYED?] if so I already know I can be annoying.

I think annoyance is a good thing like one of our senses.