It is not widely known, but that dating was not done by the Bishop of Ussher. It was done by a scientist -- one who would be on anyone's list of the top twenty who ever lived, Johannes Kepler. Ussher merely redid and checked the calculation later, and arrived at a nearly identical figure (I think it differed by twelve years). If I recall, Kepler published his result in Mysterium Cosmographicum (1596).
The calculation was, of course, biblical exegesis, and we suppose we have better methods of dating now.
18110 should have been addressed to you also.
>>The calculation was, of course, biblical exegesis, and we suppose we have better methods of dating now.<<
Not the least of which is how long it would take to deposit the layers of the grand canyon, have them compress, bend and fold and then have water wear down through a mile of solid rock.