are there any other versions of it?
A modern Olympiad refers to a four-year period beginning January 1 of the year the Olympic Summer Games
Olympiad
A modern Olympiad refers to a four-year period beginning January 1 of the year the Olympic Summer Games are normally held. 
what does noble gas mean? Odorless, colorless, monatomic gases with very low chemical reactivity. who discovered the first nobel gas? Pierre Janssen and Joseph Norman Lockyer and which was it? Helium who is the former by profession? A French astronomer what kind of work does the astronomers do? They observe astronomical objects such as stars, planets, moons, comets and galaxies who are the amateurs in this profession? Some devote a few hours a month to stargazing and reading the latest developments in research, others assist professional astronomers in research. what academic background does it need? PhD in physics or astronomy from where did the latter term derive? Astron means star and nomia means law, mention some instances when such studies were done in ancient times? The Antikythera mechanism (c. 150–80 BC) was an early analog computer designed to calculate the location of the Sun, Moon, and planets for a given date. what is that mechanism? an ancient Greek hand-powered orrery, used to predict astronomical positions and also track the four-year cycle of athletic games which was similar to an Olympiad who made it? Greek astronomers during the second century BC what is an olympiad? A period of four years associated with the Olympic Games of the Ancient Greeks. when did it start? The first Olympiad began in the summer of 776 BC
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Olympiad [SEP] Introduction
A modern Olympiad refers to a four-year period beginning January 1 of the year the Olympic Summer Games are normally held. The first modern Olympiad began January 1, 1896, the second January 1, 1900, and so on (the 32nd began January 1, 2020: see the Olympic Charter). The ancient and modern Olympiads would have synchronised had there been a year zero between the Olympiad of 4 BC and the one of 4 AD. But as the Julian calendar goes directly from 1 BC to 1 AD, the ancient Olympic cycle now lags the modern cycle by one year.