How can any size be attributed to the Singularity? Given it represents all of existence, what else is it being measured against? Can it somehow be measured against itself internally? Is the Universe that expanded from the Singularity still a Singularity? The internal structure may have changed, but isn’t it still a single entity that represents all of existence? Do we know the size of the Universe now (if so, how), and how do we know that it’s not infinite? If we don’t know how big the Singularity was, or how big the Universe is, how do we know that the Universe expanded from the Singularity? Couldn’t it always have been the same size and it has just changed internally? How does proving that the observable universe is expanding by observing cosmological redshift prove that the Universe per se is expanding? How do we know what’s happening in parts of the Universe we can’t observe? Couldn’t these parts just as easily be contracting?