Civilization One: The World is Not as You Thought it Was (5 page)

As we have demonstrated, the modern metre was derived from the polar circumference of the Earth and it was first recorded as the distance between two fine lines engraved onto a bar made of platinumiridium alloy. Later it was redefined in terms of the wavelength of red light from a krypton-86 source. Since 1983 the metre has been defined as the length of the path travelled by light in a vacuum during a time interval of one 299,792,458th part of a second.

We reasoned that the Megalithic Yard needed to be recorded in a way that was accessible to every builder, yet for the majority of the Megalithic Period this culture did not use metals of any kind. It is possible that two fine lines could have been cut into a rock at some significant location but such a procedure would be open to error and could not have produced the amazing accuracy found by Alexander Thom. As he himself observed, wooden measures would have been subject to damage from a host of different sources. Rather than keeping a ‘sample’, what our Megalithic mathematicians needed was a method of reproducing the Megalithic Yard that was simple to use, very accurate and available to people dispersed over a large distance and across a huge span of time.

It seemed to us that anyone wishing to accurately recreate the Megalithic Yard required something in the natural world that would offer them a foolproof method of recreating the subdivision of the polar dimension of the Earth that they had already established. And it had to be a process that ensured the unit of length would not change across time or physical distance. We came tantalizingly close to resolving this problem back in 1998 when Chris was putting the finishing touches to the manuscript for
Uriel’s Machine,
a book he was co-authoring with Robert Lomas. At that time the three of us got together to try and find a mechanism that could have allowed Neolithic builders to reproduce a Megalithic Yard, without being given a ruler, that was accurate to less than six-tenths of a millimetre.
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We had reasoned that if builders separated by time and space could consistently generate the Megalithic Yard, it seemed certain that each individual had followed some well understood process in order to create their own Megalithic Yard in isolation. We proceeded by considering a shortlist of the possible candidates from nature that could conceivably offer a repeatable unit of any measurement to a human observer. This list was to prove very short indeed.

We were quickly able to dismiss all living matter as a source of consistent length. Plants and animal parts (including human limbs) vary considerably from one example to the next. We discounted minerals such as crystals because they also vary in size. After a great deal of consideration the only option seemed to lie in the heavens, which did appear to be a logical possibility because we knew that Megalithic sites had been constructed using stones carefully aligned with the Sun, the Moon and the planet Venus.

So, in the end, our shortlist of possibilities for any naturally-occurring unit of measure came down to just one candidate: the turning of the Earth on its axis – exactly the same phenomenon that we have now identified as the original justification for idea of a 366-degree circle! A real pattern was starting to emerge.

Through this careful process of elimination we had concluded that the only natural phenomenon that can be accurately measured by man is the passing of time – which, we reasoned, could best be judged by watching the apparent movement of stars. The slow motion of the stars across the night sky is simply due to the Earth turning on its axis – which is as predictable and constant as anyone could reasonably need for all practical purposes. As far as we could see there was absolutely no alternative to the revolving Earth as the basis of any unit of measurement.

Back then, we had come to the opinion that stars were a more accurate means of appreciating the turn of the Earth than any of the other heavenly bodies because of the complexity of planetary movements within the confines of the solar system. Only far later did we realize that the assumption we had made was very wrong.

Our first challenge was to puzzle over the issue of how any unit of time could possibly be converted into a linear unit. Here we took a leaf from Professor Thom’s book and attempted to design our own solution to the problem that we assumed once confronted the Megalithic builders. If we could produce a method that worked for us, we reasoned, we could then compare our result with evidence from the Megalithic sites.

In order to become acclimatized to the problem we ventured out onto the Yorkshire moors in northern England on a cold, starry night to soak up the dramatic majesty of the heavens that swing over the heads of all humanity once each day. The human eye is a remarkably adaptable light detector, able to function in bright sunlight and still pick up faint starlight. With practice it is possible to see deep space objects such as the Andromeda galaxy, and in doing so we are observing light that left that faint smudge in the heavens some two million years ago – a period before our distant ancestors,
Homo erectus,
first stood upright!

We pondered the difficulty of turning the apparent motion of the stars into units of time without the benefit of a stopwatch. Today we take the concept of time for granted because we have clocks and wrist-watches to synchronize our lives, but most of us forget that the hours, minutes and seconds we use are themselves only a convenient and artificial way of monitoring the spin of our planet.

Measuring time is a real problem today, let alone more than 5,000 years ago. We now needed to try and work out how to create units of time from the spinning of the Earth on its axis, using only the technology available to the people of the late Stone Age. It seemed tough, but we eventually realized that the answer lay in a pendulum.

At the heart of a traditional clock lies the pendulum. The wind-up spring or electrical motor is merely a mechanical device to provide a power source to keep the pendulum swinging rather than have to swing it by hand. And the dial on the clockface is simply a convention to give us a standardized means of reading off agreed units of time. When we stripped away the modern aspects of a mechanical clock we realized that it is, in essence, nothing more than a swinging pendulum.

We could imagine that a hypothetical Megalithic clock could work perfectly well without a clockwork mechanism or a dial. All we needed to create such a timepiece was for two of us to take turns to swing a pebble on the end of a piece of twine with our hands while the other counted off groups of completed beats. For example, a small stone could be put in a line for every 100 beats. This ‘man-clock’ would work well enough to allow for very accurate astronomical calculations to be carried out over several days if necessary.

The time that it takes a pendulum to swing is governed by just two factors: the mass of the Earth and the length of the pendulum from the fulcrum (the point at which it is held and pivots) to the centre of gravity of the weight. Nothing else is of significant importance. The amount of effort that the person holding the pendulum puts into the swing has no bearing on the time per swing because a more powerful motion will produce a wider arc and a higher speed of travel, whereas a low power swing will cause the weight to travel less distance at a reduced speed. Equally, the heaviness of the weight of the object on the end of the line is immaterial – a heavier or lighter weight will simply change the speed/distance ratio without having any effect on the time of the swing.

The mass of the Earth is a constant factor, although there are tiny variations of the acceleration due to gravity at different latitudes and altitudes because the Earth bulges slightly at the equator, causing a minute change in the angle to the Earth’s core. However, in an area the size of the British Isles anyone swinging a pendulum for a known number of swings in a fixed period of time will have almost exactly the same pendulum length.

Pendulums certainly seemed like prime candidates. It was self-evident to us that the builders of the stone circles possessed such objects because they could not have erected their perfectly vertical standing stones without them.

A pendulum is nothing more than a swinging plumb line. All that was required was a regular-shaped weight on the end of a piece of twine – and certainly many pebbles with holes drilled through their centres have been found at these ancient sites. These are usually described as ‘loom-weights’ used in the weaving of cloth, but some could equally well be the remnants of plumb lines.

A simple pendulum

When we first looked at this problem with Robert Lomas we had outlined a technique of measuring the rotation of the Earth by standing in the centre of a large circle and watching a star pass between two pillars that were spaced to be one 366th of the circle of the horizon. We found that we could produce a pendulum length that was very close to a half Megalithic Yard by swinging the pendulum 366 times during the passage of the star. The swings required were actually closer to 365½ but we reasoned that the user would have counted the last swing in full.

Long after our joint investigation with Robert Lomas in this exercise was over, we returned to the issue of the small discrepancy between Thom’s Megalithic Yard and our pendulum-based result. The process we had identified seemed too close to be plain wrong and yet what amounted to a half pendulum swing niggled away at the pair of us. The more we thought about it, the more we felt we had missed something very significant. We decided to investigate every possible option including the use of the Sun, Moon and the planets as indicators of the passage of time. Ultimately we found our candidate and, once we did, we kicked ourselves for not having recognized it all along. It was the planet Venus that our ancient ancestors had used to calibrate their pendulum and therefore keep the size of the Megalithic Yard absolutely accurate.

A star, being millions of kilometres distant from our solar system, will always appear to occupy the same place in the sky when seen from Earth (except over vast amounts of time, which need not concern us here). But planets are a different matter. Like the Earth, planets are orbiting the Sun and so when seen from the Earth, they have movement that is independent of what we call the fixed stars. This situation is similar to a stage on which a play is going to take place. The stage, with its scenery, is like the starry backdrop we see every night, while the actors can be equated with the planets, which can move independently of the stage scenery.

As the Earth turns on its axis once each day, so the stars appear to turn over our heads. There is one band of stars, known as ‘the plane of the ecliptic’, through which the Sun, Moon and planets of the solar system appear to travel. Historically, this band was split into 12 sections, known as the zodiac. Patterns or ‘constellations’ of stars in each of the sections were thought to look like some animal, person or object and it is from this we derive the different names of the zodiac signs.

We might stand and look to the east on a particular night in the year and see the constellation of Aries rising over the eastern horizon. As the night progresses it would be replaced by Taurus, then Gemini, Cancer, Leo and so on, until one sidereal day later, when Aries would appear again. Against this backdrop we would see the planets which, in addition to seemingly follow the stars, are also slowly progressing through the zodiac constellations. The speed with which the planets appear to us to pass through the zodiac depends partly on their distance from the Sun but is also modified by the fact that we are on the Earth, which is also going around the Sun. Because of this ‘line of sight’ effect, the planets can sometimes even appear to move backwards within the zodiac.

Planetary movements can seem tortuously difficult to understand, particularly those of a planet such as Venus, which is closer to the Sun than is the Earth. From our perspective Venus can be either a ‘morning star’ in which case it rises before dawn and therefore ahead of the Sun, or it can be an evening star, in which case it is still visible in the sky after the Sun has set (though of course it isn’t a star at all, even if it looks like one). But no matter whether it is a morning or evening star, it still moves through the zodiac signs, independent of the stars.

There are periods in each Venus ‘cycle’ when it achieves a speed within the zodiac of as much as 1 degree and 16 seconds of arc per day. Since this movement is opposite to the movement of the stars themselves, Venus will take more than a full sidereal day to pass from a particular point on the horizon to that same point again.

We then had to think about our original Megalithic pendulum experiment in which we observed a star passing between two pillars with the sides angled to be at 90 degrees to the path of the stars. If we used Venus instead of a star, there would be times in each of its cycles when it would take longer to pass between the posts than would a star. We discovered that this ‘time-lag’ was just enough to account for the missing half-swing of our pendulum.