So... the total state of the universe field is the sum of the states of all its component parts, including the observer and any objects observed or unobserved.

This means the universe must be deterministic because the state of the universe at time t=0 will lead to the state of the universe at a later time t, affecting the states of its component parts. We don't have free will, we don't choose who we are, where we were born or went to school, we don't even choose what flavor bubble gum we buy at the grocery store.

This means the observed states of even entangled particles separated by vast distances are pre-determined.

This means the universe must be finite in size because an infinite sum cannot be determined exactly.

This means that spacetime itself must be massless. In an infinite universe spacetime could have mass and still not have curvature because gravity would pull equally in all directions, no matter where you are, preventing the universe from collapsing. In a finite universe, spacetime must be massless to be flat.

Unless... the universe is collapsing, and that's why it appears to be expanding - the gravity well is getting deeper and deeper all the time, and we're closer to the bottom than more distant objects!

Or, maybe we're in an ancestor simulation and extrapolating too far into the past is meaningless. But the universe is too big to just be a simulation of life on Earth. Then again, the evidence indicates the (observable) universe was once much smaller than it is now.

Definitely gets the brain cells firing!