Young Earth Creationists often argue that the reason science appears to prove that the universe and the Earth are billions of years old, rather than thousands, is because God created the universe with an appearance of age. In other words, God created the universe to look like it was billions of years old, even though by the time He got finished, it was only 144 hours old.
One justification they try to give is that Adam and Eve were created with maturity, and so was the wine at the wedding at Cana (since it was the best tasting wine, it must have been aged).
Adam and Eve may have been created as fully grown adults, but did He create them with acne scars from teenage years they never lived? Did he create them with belly buttons, giving the appearance of having umbilical cords? Did they have bags of photos from vacations they've never took? Very doubtful.
There's a different between being created in an advanced state and being created with an appearance of *history*. The universe and Earth have such signs of having endured through billions of years worth of events. The planet Earth has canyons that looks like they've been eroding for last few million years (and in case you're trying to appeal to Noah's flood to explain the Grand Canyon, let me point out that there are similar canyons on Mars). The bag of photos from the vacation Adam never took could be compared to the photographs of the universe's development that astronomers take, since it takes time for the light from the stars and planets to reach their telescopes they can actually see what a star looked like millions of years ago since it took millions of years for the light to reach their telescope. Even if God did create the universe in an advanced state, we wouldn't expect to see these things, and yet we do.
Why would God do that? Why would and how could the God who cannot lie (Numbers 23:39, Hebrews 6:18, Titus 1:2) create the universe with such deceitful features? Does God just like messing with scientists? If God created the universe to look like it had endured through billions of years of events, He would be a deceiver, which The Bible says God isn’t. “But He created Adam and Eve with an appearance of age! Does THAT make him a deceiver?” you might respond. No, for a variety of reasons. 1: As I already said, while they were created in an advanced state, it’s doubtful that they were created with features that implied they had endured through time (e.g acne scars, belly buttons, etc.). Secondly, Adam and Eve were sentient and intelligent beings, unlike the physical universe. A scientist examining Adam’s and Eve’s bodies might conclude that they’re older than they really are, but Adam and Eve have the ability to correct him. The physical universe cannot say “Hey guys! I’m actually only thousands of years old, not billions!” Thirdly, there was a good reason to make Adam and Eve as adults; if God had created them as infants, they wouldn’t have been able to care for themselves, since there weren’t adult humans that preceded them to do so. Now, God could perhaps assign an angel to raise them, but a more simpler solution would be to create them with maturity already built in.
But I can’t see any reason why He would make the universe have an appearance of age. I especially see no reason to think God would give the universe an appearance of history.
Another problem with the appearance of age argument is that it makes YEC unfalsifiable. No matter how much evidence one might try to produce to falsify YEC, it could just be dismissed with "Well, God made it look old. It's really not old." A good scientific hypothesis will have some criteria for falsification, but YEC has none unless the appearance of age argument is discarded.
It'd be kind of like the statement "All watermelons are blue on the inside until you cut them open" This statement is unfalsifiable since you don't have any criterion for proving it's not true. But also notice that not only can you not falsify it, you cannot confirm it either. You see, in order to know the color of the inside of the watermelon, you'd have to cut it open. You could cut it open and say "See? I told you it's not blue on the inside, it's red!" but the claim is that watermelons are blue on the inside UNTIL YOU CUT THEM OPEN. The claim is that as soon as you cut them open, the inside of the watermelon changes color. So, if you can't cut open the watermelon, you cannot see what the color on the inside is. For this reason, you can neither prove that watermelons are blue until you cut them open and neither can you disprove it.
To be frank; I give this explanation almost as little credence as I do the “Satan planted fossils in the ground to test our faith” explanation. It's just plagued with issues.
The appearance of age argument also destroys the foundation of science. If we can’t trust the universe yield accurate results on how old it is, what else can we not trust? Does the Earth really orbit the sun, or does the Sun orbit the Earth and God made it so that it looked like heliocentrism was true? Maybe there aren’t any galaxies and stars in the universe other than our own galaxy. Maybe God made it so that the universe looked a lot bigger than it is? You never know. If He made it look older than it really is, He could make it look bigger than it really is also, right?