For those interested: https://www.amazon.co.uk/1421-Year-China-Discovered-World-eb...
"His book 1421: The Year China Discovered the World, is a work of sheer fiction presented as revisionist history. Not a single document or artifact has been found to support his new claims on the supposed Ming naval expeditions beyond Africa."
But it is a fact that America was known and had settlements before Columbus https://en.wikipedia.org/wiki/L%27Anse_aux_Meadows
They are not exactly descendants of the Norse.