Then you're left with explaining the laws of physics and why they exist. Those laws are contingent after all. See Aquinas's "argument from contingency" (though not the general cosmological argument or Kalām variant, which are not very good) as well as Leibniz:
Aristotle would disagree:
* https://tofspot.blogspot.com/2014/07/first-way-some-backgrou...
* https://tofspot.blogspot.com/2014/08/first-way-moving-tale.h...
* https://tofspot.blogspot.com/2014/09/first-way-part-ii-two-l...
* https://tofspot.blogspot.com/2014/10/first-way-part-iii-big-...
> The only absolute laws are the laws of physics.
Then you're left with explaining the laws of physics and why they exist. Those laws are contingent after all. See Aquinas's "argument from contingency" (though not the general cosmological argument or Kalām variant, which are not very good) as well as Leibniz:
* https://en.wikipedia.org/wiki/Cosmological_argument#Argument...
* https://en.wikipedia.org/wiki/Principle_of_sufficient_reason
For a fuller treatment see Feser:
* https://www.amazon.com/Five-Proofs-Existence-Edward-Feser/dp...