The following are well-known examples of factoids, and the facts which clarify or debunk them. ...I am always glad to have Wikipedia correct my factoids, but why is it wrong to report what UNESCO says on its web site?
It is often reported that Toronto was named by UNESCO as the most multicultural city in the world. ...
Nonetheless, the belief in this status persisted for years, even finding its way onto UNESCO's own web site.
There is also a useful List of common misconceptions, but for many items, the common belief is not much different from the truth. For example:
Black holes, contrary to their common image, do not necessarily suck up all the matter in the vicinity. If, for example, the Sun were replaced by a black hole of equal mass, the orbits of the planets would be essentially unaffected, but in other situations a black hole can act like a cosmic vacuum cleaner and pull a substantial inflow of matter. ...At least there are sources for most of the items.
Mammals did not evolve from any modern group of reptiles. ... The mammals themselves, being the only survivors of the synapsid line, are the "cousins" rather than "siblings" of modern reptiles. ...
For instance, despite appearing as a word in numerous dictionaries, "irregardless" is sometimes dismissed as "not a word".