No. The 4d space time of this world is emergent from a higher physics. It appears as a phase change. If you wish to deny that the higher physics always existed, then you must deny the principle of conservation of energy and also claim that A≠A. IOWs null =something. That's not a possibility if you wish to work with a rational reality.
And most physical cosmologists recognize this and consider the failure to explain the beginning of real space and real time as a weakness of their theories, e.g. Steinhardt's cyclic, Hawking's imaginary time.
To find a closed cosmology, you must move away from the physical to the pure math or theology.
Max Tegmark's Level IV Parallel Universe is closed precisely because it is not physical, i.e. that what we perceive from a perspective inside 4D is a manifestation of mathematical structures which actually do exist outside of both space and time.
His cosmology is radical Platonism.
A Christian would not call it "mathematical structures" but Logos which is a Name of Jesus Christ, God the Creator. Logos is the Greek word which translates to Word and also to logic.
No. That's only not a possibility if we wish to work within the framework of the universe we inhabit, controlled by the laws that currently operate it.
Just some questions. From whence did the "higher physics" emerge, of which our 4D space/time is itself an emergent "phase change?"
I can readily accept the idea that what we see in our 4D world may well be just a manifestation of a higher-dimensional physics beyond the direct observational ken of human beings. But God is likewise beyond the direct observational ken of human beings. It seems in effect you are trying to put higher dimensional physics in place of God. If so, I gather that it would be okay with you if I were to ask (as other people ask with respect to God — i.e., what caused God?), what is the cause of this higher-dimensional physics?
To allege that people who do not ascribe to your cosmology hold that "null = something" is to entirely miss the point of what "null" means — which my dearest sister in Christ Alamo-Girl has been at such pains to explain to you and me.
To conclude that critics of modern scientific epistemology are holding that "null = something" is to invert what "null" actually means to such critics. Which is to say: null = absolute nothingness. Granted, such a thing as absolute nothingness is utterly beyond formulation by the human mind itself. In effect, your proposal that people like me think that "null = something" is to say that "bad thinkers" like me magically convert nothing into something — which is precisely what I cannot logically do.
Thus it seems to be you who falsely proposes that A≠A is what characterizes the thinking of people like me. If anything, we seem to be the people that gets this issue "right": Nothing cannot ever be anything, left to its own powers — of which it has none; for nothing does not exist such that it can have power or powers of any description whatsoever.
At least it seems you attribute a great deal of mental confusion to people like me, whose main difference from your own position (it seems) is that we do not believe that one can rationally reduce the world to the size of one's own mind and personal preferences. You go on to speak of the conservation of energy; but there's nothing in your proposal that seeks to answer the question of the origin of energy.
As to something as having been "always existing," it ought to be clearly obvious that there is no way in which you can support that claim on the basis of observation and experience. Temporally situated as we are, we do not see the whole of time. If there was a "beginning," we didn't see it. If there was no beginning, there was nothing to see. Such questions cannot look to direct observation for their answers, no matter how "rational" we think we are, or how "rational" we think the world is.
But if the world is in any sense rational, from whence did it get its ratio? You evidently seem to believe that this ratio is the "higher physics." Which to my way of thinking is simply to beg the question. Evidently you believe this "higher physics" is eternal.
Well, fine. Call this "higher physics" eternal if you want to. I'd say universal is the better descriptor of the situation. Still, for the world to be what it is, and not some other way, it must itself have had a cause. The logical requirement of a first unmoved (i.e., uncaused) mover to explain the phenomena of reality holds logically whether the universe is "eternal" or had a beginning in time.
Thanks for sharing your thoughts on this question, spunkets!