What's the difference between macrocosm and megacosm?

Macrocosm

Definition:

(n.) The great world; that part of the universe which is exterior to man; -- contrasted with microcosm, or man. See Microcosm.

Example Sentences:

(1) Experience with our microcosm (Ospedale Civico Lugano) was compared with the macrocosm of the results of ISIS-2 in 17,187 randomized patients (in brackets).
(2) We now have a multi-dimensional macrocosm – a true ecosystem – in which our various forms of personal computing work together, share data, media, services.
(3) An examination of Balinese medical manuscripts, in the context of the conventions of Balinese literature, demonstrates the use of these texts to align the body with the macrocosm and to reaffirm the beliefs of the ancestors.
(4) It appears that their medical concepts, to which the physikoi contributed, have been elaborated from a micro-macrocosmic method: the microcosmic man is directed by the same laws as the macrocosmic universe.
(5) While such a study provides a microcosmic view of such behavior, it is postulated that this same cyclic pattern was experienced in the macrocosm of society at large by drug-abusing populations over centuries past.