Once we get back to the unknown “first cause” then we are obviously dealing with the unknown. The unknown in this case being totally unknown with no facts existing to support any hypothesis. Any and all conjectures about the nature of the totally unknown are all equally valid creations of the imagination.
You are correct except for your last sentence. The “first cause” is a logical necessity. We (men) are logical creatures, and we like to think we can use our faculties to discern truth. Some things, obviously, make sense to us, others do not. I could say:
1. The universe popped out of some different dimension and exploded. (what started this thread, by a scientist who makes some assumptions)
2. A “First Cause” created the universe from nothing.(What Christians and Jews call “God.”)
3. A pre-existing 1959 Chevy spewed the universe out of the tailpipe, and the carbon monoxide exploded.
#3 is not equally valid as #1 & #2 might be.
We know the universe exists, and we are relatively sure that it didn’t originate from a 1959 Chevy. Whatever conjectures we consider, we need to look at the source of the information, and then consider that source. Using our logic (some say, “scientific methods”), we contemplate the possibilities and probabilities. We must rule out any which make no logical sense...maybe the 1959 Chevy. Since there is no hard evidence, we are left with philosophical possibilities. We know, from experience, all effects have some cause, but we always return to some ultimate cause, that started everything. It is a logical necessity.
It seems, Jeff, that you have pointed toward the truth, but then tried to get away from trying to discern that very truth, by saying anything is valid. “Anything” isn’t valid, but some things are valid, for an explanation. -Glenn