1In the night sky, the stars appear to revolve around the Earth,
2rising in the east, and disappearing in the west.
3The Earth itself seems solid, fixed, and stable,
4and such common sense perception suggests that the Earth is the centre of the universe.
5This is known as "geocentrism", with geo meaning Earth,
6and all pre-modern civilisations drew this conclusion.
7We now know, of course, that the Earth revolves around the sun,
8and this is called "heliocentrism", with helio meaning sun,
9but historically, it took quite a while for this to be deduced.
10As early as the third century BC,
11an ancient Greek astronomer, Aristarchus of Samos,
12proposed heliocentrism, but received little support from his peers.
13Similarly, throughout subsequent history, isolated individuals proposed this new idea,
14but again, no one was listening.
15Geocentrism just seemed too logical to refute.
16Geocentrism also fitted the views of the established Christian church,
17who could quote biblical passages such as 'the world also shall be stable, that it be not moved'.
18Those who dared to disagree were subject to accusations of heresy
19often with dire punishments to follow.
20The trouble was, as the night sky was observed more closely,
21that simple revolution of the stars proved not so simple at all.
22In relation to the other stars, some steadily wandered in given directions,
23then sometimes reversed for months, and disappeared altogether.
24They were called planets, meaning 'wanderers'.
25In addition, the position of the sun and moon altered slightly over the year,
26and comets, those mysterious glowing spots, would come and go.
27In order to predict the motion of the planets,
28and accurately serve the primary purpose of navigation for sailing ships,
29increasingly elaborate mathematical models were needed -
30a sure sign that something was not quite right.
31Heliocentrism, or the belief that the sun is the centre of the solar system,
32still needed a mathematically-sound description before it could be scientifically accepted,
33and it was a Polish astronomer, Nicolaus Copernicus,
34who, in 1543, first published this.
35This event is sometimes referred to as the Copernican revolution.
36Copernicus himself certainly feared the consequences of his proof,
37knowing full well it might invoke the anger of the established church.
38Probably for this reason, he waited until the last year of his life,
39when he was sick and dying, to release his findings.
40In addition, the preface of the book,
41written by a respected member of the church,
42stated that the model was not necessarily correct.
43As a result of this, there was no "revolution" whatsoever,
44in fact, the book received scant attention in the subsequent decades,
45apart from a few irate clergy men who angrily dismissed the whole scheme as irrelevant.
46Yet the following generations of astronomers did not always fare so well.
47The Italian scientist, Galileo, got into trouble,
48as did a fellow Italian, with the surname Bruno, Giordono Bruno,
49who was burnt at the stake,
50yet ultimately, nothing could slow the spread of heliocentrism across Europe.
51It formed the basis of Isaac Newton's great work on the motion of the planets,
52a work which implied that even the sun, around which the Earth circled,
53was itself in motion around a common centre of gravity.
54No discourse about heliocentrism could finish without mentioning that,
55somewhat unbelievably, there still exists those today who choose to believe that the Earth is the centre of the universe.
56Modern geocentrism is usually the result of literal interpretations of the Bible,
57which is the cornerstone of these people's beliefs.
58They, therefore, also believe in creationism,
59that is, that a God created everything,
60and while we may smile at this,
61it is sobering to consider that surveys have revealed that up to 10% of British people,
6212% of Europeans. 20% of the USA,
63and 25% of the Middle East,
64still hold the belief that the sun revolves around the Earth.
65One can only wonder what Copernicus would have thought of this.