Actually there are inconsistencies in the scientific data concerning the age of things. A fact that seems ignored by those holding to an old earth theory. Key word being theory.
In order to prove that the earth is really that old they would need more than just circumstancial evidence.
First of all, since the bible records God creating Adam as a grown man, Why is it not also conceivable that God also created stars and the earth In their grown from as well?? Adam would have appeared on the very first day of his creation to be a grown man, not a one day old baby. If science came on the scene the day after Adam was created, would thye have assumed his age to be older??
Secondly, just for one example of the inconsistency in the methods of dating things. I learned in my Oceanology class that the oceans are 170 million years old. This was determined by the changes in magnetic anomolies in the strips of lava on the oceans surface. By determining that the earth's poles shift periodically and thus change the magnetic "signature" of the ocean floor. Much like tree rings for determining the age of a tree. Anyway, then I learned in a seperate class that every year the amount of salt and other minerals in the ocean change each year as it is washed in from rivers and other such sources. Extrapolating back makes the ocean 60,000 years old. Quite a contradiction in the date of the ocean. 60,000 or 170 million.
The earth may appear older than it is since it was created as Adam was "full grown". But I also am of the opinion that science greatly exagerates the numbers.