tdos wrote:The Aborigines didn't tell the world that Australia existed, the Portuguese (well it can be argued they didn't as they kept it a secret), Dutch and English did.
One of the problems in the "Age of Discovery" is that prior to the 18th century, accurate clocks were not available. Although it was relatively simple to find how far north of south of the prime meridian you were by determining the angle of the sun above the horizon at local noon, and consulting an astronomical almanac, finding how far east of west one was of any point in Europe was a serious problem. For example, La Salle took an expedition to find the mouth of the Mississippi by sea (he had already marched almost all the way the mouth of the river by land), but ended up too far west, near modern day Galveston, Texas. He eventually decided that he was too far west, and took a party to march east to find the river. He was killed by his men before he reached the Mississippi.
In the 15th, 16th and 17th centuries, Portuguese, Spanish and Dutch mariners were getting seriously rich by sailing to the "East," and bringing back valuable cargoes such as silk and spices. Some expeditions would be nearly wiped out, returning with a single small ship, and the cargo would still make them rich beyond their wildest dreams.
But because of the problem of knowing how far east or west of any given point, these mariners kept "rutters," in which they described landmarks (which is why they tended to sail within sight of a coastline if at all possible--Carbral "discovered" Brazil because he was blown off course on his way to the Red Sea), water color and condition, reefs, prevailing winds, etc., all with reference to north or south of the equator. Because so much serious money was involved, these rutters were genuine top secret state secrets, and people would literally kill to get their hands on one, or kill to keep them secret. Only one of Magellan's ships survived the voyage around the earth, and it was a small one at that--but cloves and cinnamon on board paid for the entire expedition, the one ship that returned, and the three larger ships that were lost and the one that returned to Spain, and even managed a small profit.
So, especially with the Portuguese and the Dutch, when mariners returned to Europe, they either kept their mouths shut about what they had found, or they made up preposterous stories. "Discoveries" were not accurately decribed, because there was too much money at stake.