The Earth Venus conjunction features interestingly in The Da Vinci Code. Because 13 Venus years are almost precisely equal to 8 Earth years, there are 13/5 = 2.6 Venus years for each 8/5 = 1.6 earth years. The common "0.6" in the two cycles means that when Venus has orbited 2.6 times, the Earth has orbited 1.6 times, so they line up exactly again with the sun. The five inferior or superior conjunctions are therefore at 1.6, 3.2, 4.8, 6.4 and 8 earth years = 2.6, 5.2, 7.8, 10.4 and 13 Venus years. For example, the inferior conjunction of Earth and Venus on 18 August 2007 was the fifth such event since the same date in 1999. These five points form a perfect pentagram in space, the divine shape of Pythagorean lore and the Vitruvian Man by Leonardo, as discussed by Dan Brown. There is reportedly a 0.0789 day slippage of this pentagram every 584 days.