The Earth still has a molten interior. If it was really billions of years old, there would no longer be internal heat. When I took intro geology 45 years ago, this was explained as "radioactive decay results in the heat", but we know that the Earth's interior is nickel/iron, or some high-density metal that is devoid of radioactive elements. The radioactive elements are in the Earth's continental crust, and the continental crust, comprising only about 30% of the Earth's surface, is a very thin skin compared to the diameter of the Earth, and can not come close to generating the amount of heat still in the Earth. Another interesting thing is that there are deep, incised canyons extending several miles deep along the east coast of the U.S. These are clearly water-carved canyons, meaning that the ocean basins were essentially dry in the past. I remember years later, in an oceanography class, the submarine canyons were explained as caused by turbidity currents, but any rudimentary understanding of erosion processes prevents that explanation from being remotely seriously considered. I believe there are many other interesting facts about the Earth that are contrary to the established dogma of a billions of year old Earth, among other things, but my memory isn't good enough to recall without Google :)