A: Let’s say someone found a big deposit of gold in the middle of the Sahara…
B: There’s no gold in the Sahara.
A: Yeah, but let’s just say someone found some…
B: But there is no gold there…
A: But if there was…
B: But there isn’t.
A: Okay, but if a deposit of gold happened to be discovered in the Sahara…
B: But you won’t! It’s not there!
Etc.
C’mon, there’s a great sci-fi novel I can’t marimba the dang title or author of from 20 years back, where a C19th America, as I wrongly recall, wakes up to an empty world.
I played. Do I get a prize? 
I would vote for you, and so would @originmike, I think, based on this and his corresponding reply. 
The answer is still no. This is not one piece of evidence or one kind of evidence but million of pieces from hundreds of different directions and sources. They all make the conclusion inescapable. That is why we have esitimates of the age of the universe getting more and more precise over time as more data of different kinds keep narrowing the possibilities.
Already played that game. The inescapable conclusion for me was that I had moved into an alternate reality or different phase of existence (as in via death or dream). An alteration of the evidence is no different from an alteration of memory or alteration of the past.
If you remember, please post it. I’m always looking for good sci-fi.
But Newtonian physics accounted for almost all the existing evidence in the late 1800s. Relativity and quantum mechanics not only did a “better job,” but at the small and large scales, actually contradicted Newtonian physics.
Estimates of the age of the universe are one thing, but we actually use models and “predict backwards” for things like “expansion periods.” It’s not observation, but models and predictions.
Consider the conspiracy theory that “light is actually slowing down.” Imagine if that were proven true? It would change everything about what we know.
And the first test of relativity was that it agreed with Newtonian physics on all the same evidence where it worked. It improved upon Newton by doing a better job in those places where Newtonian theory failed.
Unlike declarations of theology, these models and predictions can be tested in hundreds of different ways in a number of different sciences.
No it would not change everything. It would either run into inconsistencies or become a meaningless unfalsifiable irrelevance much like the idea of the universe being created this morning with all of our memories as they are. A universal change in an arbitrary measure has absolutely no effect on anything observable. This is the basis of renormalization in quantum field theory.
To be sure we can insist on literal interpretations of Genesis by claiming that everything in the past simply moved faster and in that way cram 13.7 billion years into seven days. But that is ultimately just switching to a definition of time that is ultimately meaningless. It has no real value and smells of desperation like a barrel of rotten fish.
It’s not. It can’t. Why bother? We know all we’ll ever need, or get.
And I will track that book down.
You seem to be implying some kind of dichotomy between theology and science. The hypothetical premise was about a scientific proof impacting one’s theological perspective. Not the other way around.
Again, that’s the game we’re supposed to be playing.
Nobody’s insisting on that.
Once again, it’s a game. A thought experiment. IF a young-universe were proven, how would that affect your theology.
You seem to insist we’re playing the opposite game:
IF your theology was young-universe, how would that affect your science.
We know all we’ll ever need, or get?
Do you mean that completely? Like, there’s no point in pursuing further knowledge?
I’d appreciate that, thanks.
There’s every point for knowledge’s sake but it can’t make any difference to any of this typically Western - white - dominant culture theologizing that we do and to the good news.
Speaking purely for myself, here are three reasons why I like thought experiments like this me:
I am so happy to hear that you have returned to Christianity after a period of atheism. But I’m also sorry to hear that you have been encountering a stumbling block at church.
Whatever they may say, remember that nothing can separate us from the love of Christ (Romans 8:35-39). This is my encouragement to you, and I hope it helps.
For pragmatic realists like myself, these types of games aren’t that illuminating. Imagining fictional realms can be fun, but it really doesn’t tell us much about the real world other than a certain quirk of human psychology.
What if everything I think is true is actually false? Then I guess it is false. Until such a day comes, I will continue to think it is true. More to the point, if we have to invent a fictional realm in order to have a 10,000 year old Earth then that says a lot about the actual evidence.
I am not buying that rhetoric. I have played the game and answered the question repeatedly. If you were actually interested in the question then you would have focused on those replies and made a comment on them. Instead you seem to be playing a very different game of using this as cover under which to sneak in a lot of unwarranted claims about science. And no that is a game which I will not play.
So come on… a little honesty here for once. If you are interested in the supposition of the OP then talk about my answers to that question instead. And here for the third time is what I said. The inescapable conclusion for me was that I had moved into an alternate reality or different phase of existence (as in via death or dream).
That is not a game I would EVER play even for a second. For me science has always come first and I will only ever consider religion and theology which is in agreement with the findings of science – otherwise I would consider it meaningless nonsense. I have made that crystal clear. I can pretend going to a different universe where the rules are different but it is simply absurd to pretend that I myself am other than who I am. To ask what I would say if I were a different person is a contradiction in terms… you can only ask what someone else who is different would say.
I find the strong reactions to the premise of this thread intriguing. Why get so hot under the collar about it?
I personally think football (soccer) is a boring waste of time. But I don’t go over and tell that to the lads having a kick about in the park, I just don’t play.
Similarly, If you think the thought experiment is silly, or illogical, or [fill in the blank] then don’t play along. Why stop by just to say the game is not worth playing? 
It’s funny that you would post on a board like Biologos Forum and have this response.
I think the theological implications of YEC vs. “old universe” are significantly relevant.
Are you suggesting that I’m trying to push for a YEC POV?
Or…“a lot of unwarranted claims about science”?
Seriously?!
Once more, the game is about theological implications, not scientific implications.
You want there to be theological implications. I saw none.
What if we change the question to the following?
If the Earth was no more than 10,000 years old, what would be the theological implications?
For me the implication would be that Christianity is nonsense. Gnosticism with its evil creator would make more sense.
“Let your conversation be always full of grace, seasoned with salt, so that you may know how to answer everyone.” -Colossians 4:6
This is a place for gracious dialogue about science and faith. Please read our FAQ/Guidelines before posting.