This sounds like an accusation that was regularly thrown at Medieval Aristotelian physicists. Aristotelian physics was built around the "teleological" principle that things have natural tendencies to strive to achieve certain goals or destinations. Why does a stone fall? Aristotle would say that the explanation for this rests on the fact that it is in the nature of an earthy body to move towards the natural place of such bodies, which (he believed) is in the centre of the cosmos. But you're quite right, this does sound rather vacuous, to say that it moves as it does because it has a natural tendency to do so. The Aristotelians sought to explain natural phenomena in terms of what came to be known as "occult qualities" and, although the term "occult" might not have carried quite the connotations it has now, it was used perjoratively by many non-Aristotelians to point to the fact that these supposed qualities really weren't explanatory at all. The Aristotelian approach was famously lampooned by Molière,...

In the century and a half following Copernicus, when the debate around this issue was at its height, there were actually several major differences of opinion between those figures (such as Kepler, Bruno, Galileo or Descartes) whom we tend to lump together as adherents of the new astronomy. The debate between Medieval and modern astronomers is usually set up in terms of a pair of interconnected differences of opinion, over (i) whether the Earth or the Sun is stationary or moving, and (ii) whether the Earth or the Sun is at the centre of things. The Medieval view was that the Earth was stationary at the centre of the universe and the Sun revolved around it; the modern view was that the Sun was at the centre and the Earth revolved around that. Except that that's too simplistic. With regard to that notion of a centre, some people (like Bruno) were firmly committed to the notion that the universe was infinite, and they explicitly stressed that no centre could be defined in an infinite universe at all,...

Short answer : You say: "That is, if an infinite amount of time was necessary to get to the present time?" But to get to the present time from when ? The natural impulse is to say: to get here from the first moment. But, of course, the hypothesis of an infinite past means precisely that there was no first moment. So, again, where are we going to start counting? To get here from a time ten years ago will take ten years. To get here from a time twenty years ago will take twenty years. So, given an infinite past, we can pick a time infinitely long ago, and it will take infinitely many years to get to here from there, right? Wrong. The hypothesis of an infinite past does not mean that there was a time infinitely distant from the present. What it means is that there are infinitely many past moments of time, each one of which is some finite distance from the present. Now, this hypothesis may well be false (I take it that both the physicists and the theologians would agree that it is, albeit for...