All Acronyms. BLUF [Internet]; Jan 15, 2018 [cited 2018 Jan 15]. Available from: http://www.allacronyms.com/_Military/BLUF. MHRA 'BLUF', All Acronyms, 15 January 2018, <http://www.allacronyms.com/_Military/BLUF> [accessed 15 January 2018] Bluebook All Acronyms, BLUF (Jan. 15, 2018, 11:01 PM), available at http://www.allacronyms.com/_Military/BLUF. CSE All Acronyms. BLUF [Internet]; January 15, 2018 [cited 2018 JAN 15]. Available from: http://www.allacronyms.com/_Military/BLUF.
The noun PTOLEMY has 2 senses: 1. Alexandrian astronomer who proposed a geocentric system of astronomy that was undisputed until Copernicus (2nd century AD) 2. an ancient dynasty of Macedonian kings who ruled Egypt from 323 BC to 30 BC; founded by Ptolemy I and ended with Cleopatra. Familiarity information: PTOLEMY used as a noun is rare.
Copernicus died the same year his book was published. After 1,400 years, Copernicus was the first to propose a theory which differed from Ptolemy's geocentric system, according to which the earth is at rest in the center with the rest of the planets revolving around it. he word helios in Greek means sun.. Heliocentric means that the sun is at the center. A heliocentric system is one in which the planets revolve around a fixed sun. Thus Mercury, Venus, the Earth, Mars, Jupiter and Saturn all revolve around the sun.