Photons lose all their energy as they redshift toward infinity at the cosmological horizon.

“if we have a horizon where at that place all the objects are receding at the speed of light right okay so when the photon sort of catches up with that right at that point it has red shifted to infinity and it's got nothing for you it's got nothing for you yeah wow so that's the it red shifts to Infi”

Universe expansion is best understood as space expanding into higher dimensions or through the dimension of time.

“the expansion into you can think of as a different dimension you can think of it as a say space being three-dimensional length width and height expanding into a fourth dimension which is yes with the fourth dimension of space which is not linked with their height or you can actually think of it as a”