common Irish surname, Gaelic Murchadh "sea-warrior." The Celtic "sea" element is also in names Muriel (q.v.), Murdoch (Old Irish Muireadhach, Old Welsh Mordoc "mariner"), etc. As colloquial for "a potato" by 1811, apparently in allusion ot it being a staple food of the Irish.
Murphy bed (1912; in full Murphy In-A-Dor Bed) is named for U.S. inventor William Lawrence Murphy (1876-1959). By happy coincidence, Murphy was an illiterate 18c.-19c. perversion of Morpheus, god of sleep. Murphy's law (1958) is used of various pessimistic aphorisms. If there ever was a real Murphy his identity is lost to history. Said to be military originally, and it probably pre-dates the earliest printed example (the 1958 citation calls it "an old military maxim").
No history of the subject would be complete without some reference to the semilegendary, almost anonymous Murphy (floreat circa 1940?) who chose to disguise his genius by stating a fundamental systems theorem in commonplace, almost pedestrian terminology. This law, known to schoolboys the world over as Jellybread always falls jelly-side down, is here restated in Murphy's own words, as it appears on the walls of most of the world's scientific laboratories:
If Anything Can Go Wrong, It Will.
[John Gall, "Systemantics," 1975]