Philosophy is the study of the natural and theoretical nature of knowledge, reality, existence, and being. Philosophy can broken down into categories based on subject and technique. See the branches of philosophy.
Most people have about 6 degrees of separation (small world theory), but not everyone has 6 degrees of separation from Kevin Bacon or any other given person.
Multiple discovery is the hypothesis that many discoveries and inventions are made independently, and more or less simultaneously, by multiple people.
A Factoid is a brief piece of information that appears to be true, but isn’t necessarily factual or verified, yet is repeated as fact anyway.