If our universe is inflating, which means it is getting bigger and bigger in size, and every thing it consists of is also enlarging, in a special way such that the mass of the universe remains constant and only the volume changes.
In that case, how will we observe the changes in the physical layout of the universe? In particular, are these guesses correct?
We will observe that the speed of light is decreasing, as light usually travels $3*10^8$m, in a second, but now since the universe is inflating, it will travel something lesser then that for instance $1.5*10^8$
As far as observation is considered, I dont think we will see any changes, since the retina of our eyes would then also have enlarged,
As far as physics of the universe is considered I think the planets will keep to their orbits as their mass has not changed a bit and they maintain same distance with other celestial bodies as they used to,