The current theoretical model for the composition of the universe is that it's made of normal matter, dark energy and dark matter. A new University of Ottawa study challenges this.
I’m no expert, and I don’t think we know for sure, but it sounds like it might be related to the increase in vacuum energy from the added space. It’s also possible the total amount of net energy in the universe is 0 and conserved
Light does actually just lose energy to nowhere in our current understanding of expanding space.
How does this reconcile with the first law of thermodynamics? Or does it just not?
I’m no expert, and I don’t think we know for sure, but it sounds like it might be related to the increase in vacuum energy from the added space. It’s also possible the total amount of net energy in the universe is 0 and conserved