Читать книгу Simple Stargazing - Anton Vamplew - Страница 7

In the distant past, astronomy and astrology were as one. Ancient rulers needed to know their fortune and, as the sky was where their gods lived, it was also where their destiny lay. Along with all the ‘fixed’ stars of the constellations were seven things that moved: the Sun, Moon and five planets – Mercury, Venus, Mars, Jupiter and Saturn (this was, of course, in the days when everyone believed that the Earth was the centre of the Universe and other sky objects moved round it).

It was an absolute belief that leaders who could understand how these objects moved could stay in control and defeat their enemies. One thing was clear: to these ancient watchers of the skies these seven objects followed a ‘path’ around the heavens – just like a car on a race track that takes the same route round again and again. It was the constellations situated along this ‘path’ that became our 12 famous signs of the zodiac.

Of course, in order to know where any object would be in the zodiac at any given time, a certain amount of calculation was required. This is when the science of astronomy was born. So, strangely, the necessity for fortune-telling encouraged the formation of science. By the way, zodiac means ‘line of animals’ (11 of the original 12 constellations are still animals) and is also linked to the word zoo.

So, why do the planets, Sun and Moon appear to move through the skies? Well, they each appear to move for different reasons. Of course the main movement you see is due to the Earth spinning – this gives us things like sunset, the Full Moon rising over frosty trees, time for your cornflakes for breakfast as the Sun rises, etc. The Moon, if it is up, additionally appears to move extremely slowly hour by hour in front of the stars because it is orbiting the Earth. The Sun changes its position against the stars day by day due to the fact that we are orbiting it. The planets move because they too are orbiting the Sun – plus each planet is moving at a different speed. No wonder it was all difficult to calculate, and indeed it’s hardly surprising that some early astronomers ended up having their heads chopped off, when their erroneous adding up was followed by a total overreaction from their bad-tempered rulers.