The British submarine engineer and historian Gavin Menzies gave an astounding seminar on March 15, 2002 to the Royal Geographical Society in London, with evidence to support his theory that Zheng He, a Chinese Muslim navigator in the Ming dynasty, also discovered America.
Using evidence from maps drawn dated before Columbus' trip that clearly showed America, and astronomical maps traced back to Zheng He's time, Menzies is confident that the Zheng He should be honored as the first discoverer of America.
Menzies's conclusion is based on 14 years of research that includes secret maps, evidence of artifacts, and apparent proof of the voyage provided by the modern astronomy software program Starry Night.
As key evidence for a voyage that will remake history, Menzies says he obtained ancient Chinese navigation charts associated with the travels of Zheng He. The journey ran from 1421 to 1423. Menzies maintains that the ships sailed around the Southern tips of both Africa and South America.
The late evening southern sky as it would have looked on March 18, 1421, from off the southern tip of South America. Reconstructed with Starry Night Software to compare with maps found from Zheng He's voyages.
"I set Starry Night up for dates in 1421 for parts of the world where I thought the Chinese had sailed," explained Menzies, a navigation expert and former Royal Navy submarine commander. He found that in two separate locations of the voyage, easily recognizable stars were directly above Zheng He's fleet.
Those stars have since moved, due to changes in Earth's orientation in space. Earth's spin is slightly imperfect, and its axis carves a circle on the sky every 26,000 years. The phenomenon, called precession, means that each pole points to different stars as time progresses. Menzies used the software program to recreate the sky as it would have looked in 1421.
"I had Chinese star charts, and I needed to date the charts," he said. "By an incredible bit of luck, one of the courses they steered, between Sumatra and Dondra Head, Ceylon, was due west."
This part of the journey was very near the equator in the Indian Ocean. Both Polaris, the North Star, and the bright southern star Canopus, which was very nearly above the celestial south pole, were on the charts. "From that I was able to determine the apparent shift of Polaris (due to precession). I could therefore date the chart to 1421, plus or minus 30 years."
Phillip Sadler, a celestial navigation expert at the Harvard-Smithsonian Center for Astrophysics, says the estimation of a map's age based on star positions is possible. He said an estimate within 30 years, as Menzies claims, is possible.