Creationists often claim that radiometric dating is unreliable, fraught with error, etc - and is therefore provides no proof that the Earth is older than 6,000 years.

 

On the other hand, the methods that astronomers use to measure the distance between us and distant stars, galaxies, etc, are known with a fairly high degree of mathematical precision. Partly because they can be based on direct observation - and partly because of the distances involved (which are literally astronomical).

 

Those findings indicate that the universe is several billion years old - and while that may not prove the Earth's age, it at least sets a lower limit on the age of the universe.

 

I'm curious what the young-Earth creationist explanation for this is? Why would God create the universe, then wait the better part of 18 billion years before creating us?