Creationist view of radiometric dating
YECs believe that most rocks were laid down in two main episodes.
The first was during the creation week, particularly when God caused the waters of the Earth to gather together into the sea and dry land to appear. The effects of a global watery catastrophe would have been enormous, which would form massive amounts of erosion and sedimentation during a short period of time.
Young earth creationists also believe that many of the mountains, valleys, and lakes we see today were formed by the geological transformations caused by the flood.
Whilst Humphreys' model has time dilation caused only by gravity (per Einstein's General Theory of Relativity), Hartnett's model also takes into account time dilation caused by motion (God's expansion of the universe) (per Einstein's Special Theory of Relativity).