Infinity, which is boundarylessness, is a sometimes helpful construct in mathematics but it doesn't translate well in physics:
Thus cosmology is stuck with a beginning; it must recognize the void, not simply appeal to infinity.
To visualize the issue, consider the number zero v. null. One could meditate about a line of all possible numbers. Zero would be at the center. Negative numbers would proceed in one direction 1, -2, -3 on to infinity. Positive numbers would proceed in the other direction 1, 2, 3 on to infinity. But if one were to reverse direction by decimal extensions counting from 1 and 1 towards zero, reducing by half (or any percentage less than 100) each time - the number would continually be smaller but the process would never arrive at zero.
The same may be said of decimal extensions in other scenarios (such as the extension of 1/3) but zero is unique because it serves as a placemarker, e.g. 201 means there are no tens. Not that tens dont exist, but for this particular number there are no tens.
But null is much more than a placemarker it is more like the zero we can identify but not approach. To use the 201 example, if we were to state 2_1 we would be saying that tens do not exist at all.
With regard to physical reality, null is infinite non-existence empty, void. This is the context of a beginning, of Creation not merely zero spatial and/or temporal dimensions but null itself no physical laws, no physical constants, no causality, no energy/matter, no physical object or event. Consequently, no phenomenon, no mathematics, no logic, no reason, no qualia, no autonomy, no language, no universals. When everything else is removed, in the void, all that there is is God Himself, the only possible uncaused cause. Thus the beginning and existence is an act of His will.
Jewish mystics use a Hebrew term for this state to describe God as creator: Ayn Sof. The term basically means no-thing - One without end from which all being emerges and into which all being dissolves.
All cosmologies whether big bang, multi-verse, multi-world, ekpyrotic, cyclic, chaotic inflation, imaginary time require a beginning (uncaused cause in the void) - because all of them require geometry for physical causation.
Quite an intricate expression of logic to arrive at this end above.. I'm impressed.. and it lead me to this thought..
Useing God in the Painter metaphor..
Supposition: In the begining God decided to paint a Universe and ultimately to paint mankinds portrait.. into that landscape.. Well there is no reason God could have Not Done this many times and in many ways before this event.. He might have many paintings.. probably does..
Diagnosis: Maybe here was no big bang.. this Universe is merely a painting by God.. and it came about as a painting comes about.. No banging at all.. it just seems so to 20th century physics "eyes".. A frog in a well surveying the heavens AND the WELL, forgeting hes merely a frog.. How?.. let there be light or let there be a Universe and it was so.. After all what does a painter do.. He sees it in his mind and makes it happen, quite 3rd dimensionally..
Notes**..
Humans paint in one way; paint, canvas(medium), brushes, like that.. God paints in another.. How does God paint.?. Who knows, but speculateing could be fun.. And art especially creative arts starts with the desire to do it and various steps to complete the task.. If God is not an artist then what is he.?..
Even engineering is an art.. Among humans we have 2 dimensional art and arts and 3 dimensional art and arts.. Gods art must surely be 4th dimensional art.. Not mimicing matter(2D art ), not shapeing matter(3D art) but creating matter(4D art).. NOW thats what I call a dimension.. Because literally every thing I know in the 3rd dimension (this world and Universe) is 3 dimensional.. even the 1st and 2nd dimensions in this world are 3D.. The 1st and 2nd dimensions are merely mental constructs they don't actually exist.. only the 3rd dimension exists.. that we can PROVE.. A 2 dimensional painting is not 2 dimensional at all, its 3 dimensional cause it has depth.. the depth of the paint and canvas..
The human spirit if "thingly"(thanks to Boop) might be 4th dimensional even now.. but linked/limited to these bodies for a purpose.. What purpose, read your bible.. We have time in the 3rd dimension so how can it be the 4th dimension.. How ever the fourth dimension (if there is even one) might take 3rd dimensional things up a notch and add something else.. What?... LoL.. read my book.. the Universal Canvas.. (rhetorical comment)..