The words "serious", "scientist", and "proven" have specific, non-supernatural definitions when used together in the same sentence, and this is the spirit in which I had written them.How is that not exactly as I described it, as evaluating a supernatural hypothesis? Surely the "proof" would be have to be observed data, or you'd be done. The "existence of God" part is the supernatural hypothesis that the scientist is offering to explain the data. Unless it were very different than every previous such invocation of a deity, it must be rejected out of hand as not science.
God is a concept which is supernatural to the extent that it (He, so as not to be offensive) cannot be proven but must be accepted on faith.
If a serious scientist claimed scientific proof for the existence of God, I would want to see his work and evaluate it, if for no other reason than to show where he is mistaken. I would be skeptical, but I would not dismiss it out of hand.
Note that I would not accept the absence of a natural explanation as proof of the supernatural.
I will ask the question again: if a serious scientist has no business investigating the existence of God, is it also true that he has no business attempting to prove God's non-existence (i.e Stephen Hawking)?