In a Word: Discovery
The word "discovery" is tricky. How can we say "Columbus discovered America," when there are Indians on the shore staring back at him? The word "discover" comes from a Latin word meaning "to uncover." In Portuguese, descobrir means "to find by chance." For navigators of the 1400s, "discovery" means "I found a new way to look at this shoreline and I wonder how it fits in with what I already know." Unfortunately navigation at this time is hit or miss... mostly miss. For example: 200 years later when the Mayflower sets out to drop off the Pilgrims at the Virginia colony, they will miss their destination by a few hundred miles. This was considered "good navigation" for the 1600s. Thus when we say "Bob, the sailor, discovered the West African coast," we mean "Bob found something new to him and he must figure out if it is something already known to those who sent him." Nothing more. Really.   
Star Fleet... Exploring Strange New Worlds
In the modern day, a British history buff will make sensational claims that the Chinese of the Ming Dynasty made a trip to America and provide the original maps for Christopher Columbus. The Star Fleet of China is a mission of exploration, but that exploration has been limited to India, Sri Lanka, East Africa and what is the modern day Middle East. But the Ming dynasty will be pulling the fleet back soon. Fighting against the Mongols will seem more important.   
Ridding the City of Injustice... and Jews
The accusation against the Jews of Vienna is host desecration but at this point the charges are irrelevant. One way or another, the Jews will be expelled from Vienna or killed outright. The Pope has called for the Jews to be brought into the religious community, meaning... convert or die. 200 Jews have barricaded themselves in the synagogue and after three days have set the synagogue aflame rather than be taken alive. Years later a plaque will be set in the Jewish Square commemorating how the Viennese "rid the city of all injustice." It will remain in the square well into the modern day while a Holocaust Museum is built in the same square. The plaque will finally come down in 2014.       
This Year in Wikipedia
Year 1421, Wikipedia.
- Brotton, Jerry. A History of the World in Twelve Maps. New York: Viking Penguin. 2012. (BOOK) quote="For people in the early sixteenth century, the discovery of new places, even new worlds, was regarded with caution, even suspicion. It challenged the foundations of knowledge inherited from classical writers like Aristotle and Ptolemy, and even questioned biblical authority: if the new world of America and its inhabitants really existed, why were they not mentioned in the Bible? The problem was compounded by the variety of inconsistent and often contradictory meanings associated with the word 'discovery' and the contemporaneous rise of European vernacular languages. In English the word only became common currency in the later sixteenth century, where it has at least six different meanings, including 'to uncover', 'disclose', or simply 'reveal'. In Portuguese, one of the first languages to record the new seaborne 'discoveries' from the early fifteenth century onwards, the term descobrir, usually translated as 'to discover', was regularly used to mean 'exploring', 'uncovering', but also 'finding by chance', and even simply to 'pick up'."
- Webster, Noah. (author) Grove, Philip B., (Editor-in-chief)) Webster's Third New International Dictionary of the English Language Unabridged ... with Seven Language Dictionary: Discovery. Encyclopedia Britannica, Inc. 1981. Vol 1, p. 647. (DICTIONARY) See discover... as in "uncover." From the Latin discooperire "to uncover." Definition: 1 a: the act, process or an instance of gaining knowledge of or acertaining the existence of something previous unknown or recognized. 1 b archaic the act of making known : REVELATION, DISCLOSURE : [...] e obs EXPLORATION, RECONNAISSANCE, INVESTIGATION &to make a more perfect ~ of the island Daniel Defoe
- Mayflower - Wikipedia, 2014 [last update]
- King James Version - Wikipedia, 2014 [last update]
- Strong, James. Strong's Exhaustive Concordance (Compact edition). Grand Rapids, Michigan: Baker Book House. June 1985. ISBN 9780801081088. (BOOK) Strong's Number: 7523, primary root. probably to dash into pieces, i.e. to kill a human being, especially to murder.
- 1421: The Year China Discovered the World - YouTube. Paladin Invision Production for Penguin Television in association with PBS. 2013 [uploaded to YouTube]. (VIDEO)
- Menzies, Gavin. 1421: The Year China Discovered the World. William Morrow. January 7, 2003. (BOOK)
- Zheng He - Wikipedia, 2014 [last update]
- Truzzi, Marcello. On the Extraordinary: An Attempt at Clarification. Zetetic Scholar, Vol. 1, No. 1. p. 11. 1978. (JOURNAL) quote: "An extraordinary claim requires extraordinary proof."
- Green, David B. This Day in Jewish History: Vienna Jews who Rejected Baptism are Burned Alive, Haaretz.com, March 12, 2014. (WEB NEWS) Quote: "On March 12, 1421, the surviving Jews of Vienna -- those who had survived the past year's incarcerations, tortures and drownings, and who had not already chosen suicide over conversion -- were set on fire, thereby “rid[ding] the city of all injustice,” as a plaque erected on Vienna's Judenplatz read until only recently."
- Judenplatz - Wikipedia, 2014 [last update]
- Judenplatz Holocaust Memorial - Wikipedia, 2014 [last update]
- Historical Timeline of Vienna (PDF). Expat Center Vienna. 2014 [last update] (TIMELINE) Quote: "1421 Pogrom on the “Gänseweide” (goose pasture). Some 200 Jews were burned alive on March 12."
- Bell, Bethany. Austria's delayed Holocaust memorial. BBC News. 25 October, 2000. (WEB NEWS) Quote: "Excavation work on the baroque square revealed the remains of a medieval synagogue where dozens of Jews committed suicide in a pogrom in 1421."
- Rosenberg, Stephen Gabriel. Vienna's underground synagogue. Jerusalem Post. Aug 21, 2008. 2014 [last update] Quote: "In Vienna the poorer Jews who refused to convert to Christianity were deprived of their meager property and foodstuff and set on rudderless boats on the Danube which floated them into Hungary, where it seems they managed to survive. But Vienna did not see them again for 200 years."
- Jewish Vienna : Judenplatz & Stadttempel, Synagogues & Jewish Museum. TourMyCountry.com, 2014 [last update]