Indeed, one writer has recently described Book 9 as "the book Galileo was supposed to write". Within Book 9 Riccioli discusses 126 arguments concerning Earth's motion — 49 for and 77 against. To Riccioli the question was not between the geocentric world system of Ptolemy and the heliocentric world system of Copernicus, for the telescope had unseated the Ptolemaic system; it was between the geo-heliocentric world system developed by Tycho Brahe in the 1570s (in which the Sun, Moon, and stars circle an immobile Earth, while the planets circle the Sun – sometimes called a "geo-heliocentric" or "hybrid" system) and that of Copernicus. As the frontispiece of the New Almagest illustrates (see figure at right), Riccioli favoured a modified version of Tycho Brahe's system; here is how he described the system that "came to [his] mind" when he was in Parma : "it shares everything with the Tychonian system, except the orbits of Saturn and Jupiter; for [me] their center was not the Sun, but Earth itself". Many writers make references to Riccioli's analysis and the 126 arguments. However, translations of arguments of the New Almagest, and discussions of the arguments to any extent by more modern writers are rare: only for three arguments of the 126 are such translations and discussions readily available. These are, first, an argument Riccioli called the "physico-mathematical argument", which was related to one of Galileo's conjectures; second, an argument based on what today is known as the "Coriolis effect"; third, an argument based on the appearance of stars as seen through the telescopes of the time. The "physico-mathematical" argument Riccioli discusses the physico-mathematical argument in terms of arguments both for and against Earth's motion. Galileo offered a conjecture in his 1632 Dialogue that the apparent linear acceleration of a stone falling from a tower was the result of two uniform circular motions acting in combination – the daily rotation of Earth, and a second uniform circular motion belonging to the stone and acquired from being carried along by the tower. Galileo says that [T]he true and real motion of the stone is never accelerated at all, but is always equable and uniform.... So we need not look for any other causes of acceleration or any other motions, for the moving body, whether remaining on the tower or falling, moves always in the same manner; that is, circularly, with the same rapidity, and with the