It has recently been discovered that the rotation planet Venus is slowing down. In the sixteen years between Magellan and Venus Express the period of Venus’ rotation increased 6.5 minutes. This shows that the planets rotation has slowed significantly over the last 16 years. While not the only possible explanation the most likely one would be tidal forces with the sun. If this is the case then 4.5 billion years ago Venus would be spinning impossibly fast. The result is that Venus can not be 4.5 billion years old. This actually works other models such as atmospheric drag as well.
------ Charles Creager Jr.