Template:Are You Sure/April 13

• ... that true muonium is a theoretically predicted exotic atom made up of an antimuon and a muon which has yet to be observed, but may have been generated in the collision of electron and positron beams?

• ... that consequentia mirabilis was a pattern of argument popular in 17th century Europe that first appeared in a fragment of Aristotle's Protrepticus: "If we ought to philosophise, then we ought to philosophise; and if we ought not to philosophise, then we ought to philosophise (i.e. in order to justify this view); in any case, therefore, we ought to philosophise."?