Our Cosmic Ancestors (16 page)

I want to say in conclusion to this chapter that the freedom of the unbiased mind has to be applied also to the recognition that probably everything we invent now has been invented already, and reinvented, thousands upon thousands of years ago. Civilizations come and go, often without leaving a trace. Sometimes a remnant of the past is left behind to make us at least suspect that man was more intelligent and advanced in an earlier civilization that disappeared. The Rhodes calculator is such a remnant of the unrecognized past that miraculously escaped the destruction of a very ancient civilization.

THE KINGS OF THE SEA

Until a few years ago everyone believed that it was impossible to navigate oceans without compass, sextant, chronometer, or the sighting of land. The question of how our ancestors then managed to reach distant lands across open seas was unanswered. We know primitive compasses and sextants existed, but there were no chronometers deemed necessary to determine the longitude. The first such transportable clock movement was fabricated in France around 1525, but the first ship chronometer dates back only to 1736 when, after eight years of hard work, John Harrison of England completed his masterpiece.

The official scientific answer to the riddle of how men could navigate was simple. We were told our forefathers never let land out of sight and navigated along the coast only. This we were taught in school and this we were supposed to believe even though it was only one of the many blunders that our learned academicians were guilty of. Another fallacy in the same category was the tale that the American continent was populated by migrants who came from Asia over the frozen Bering Strait, even though archaeological and ethnological discoveries demonstrate conclusively that men did know how to navigate tens of thousands of years ago and had no need to wait from one ice age to the next to make the crossing to Alaska. In fact, they didn't hesitate to cross the ocean on rafts or on ships.

Still, how exactly did they do it? By what means were they able to determine in open sea the two coordinates of longitude and latitude in order to know where they were and where to go? The theory that all ancient ocean crossing were accidents caused by wind or current could not be true. Too many legends report of planned voyages and of heroes who visited distant lands and returned to tell about their adventures.

When ancient Roman coins were found in Venezuela, Sumerian mining colonies discovered in Peru and Bolivia, and Hindu cotton and jute plantations traced in Mexico, I began wondering and searching again for the answer to the riddle of ancient navigation, and now I believe that I have found the answer. Instead of chronometers, they
used sunset and moonrise tables that were skillfully calculated for every day of the year, in the case of long voyages, and for many years to come. Thus at any time a navigator of a ship on open sea could determine his location by comparing the actual intervals of sunset and moonrise to those charted for the same day for his home port.

Since latitude is easily determined by astrolabe or primitive sextant, the difficult part was the determination of the exact time span between the moments when the Sun disappeared and the Moon showed up. It was done by a battery of hourglasses set to measure a fraction of a minute. Let me explain with an example from our recent past what the sunset-moonrise timing has to do with the geographic longitude that has to be found.

Astronomical phenomena of short duration, like an eclipse, are never seen at the same time at different points of the globe. So, for instance, during the solar eclipse of 30 June, 1973, that lasted 7 minutes 3 seconds, the shadow of the Moon was running eastward over our Earth in a narrow band 240 km wide at a speed of 2,150 km per hour.

In order to observe the eclipse a little longer, seven astronomers from England, France, Scotland, and the United States used a supersonic Concorde equipped with all necessary instruments to fly east at an altitude of 17,000 m (56,000 ft.) so they could watch the eclipse for 84 minutes. To enable them to do this, the plane naturally had to move with the same speed as the shadow of the eclipse - 2,150 kmph
- which it did easily. This eclipse came exactly nineteen years after the mysterious one of 30 June, 1954, that we will discuss later on in this book.

The time of totality of the June 1973 eclipse varied one full minute for every 36 km at the same latitude. If the eclipse took place over point A at noon, seeing it in point B a full hour later would mean that the distance east from A to B, if both of these points are on the same latitude, was exactly 2,160, or 60 times 36 kilometres. Now, eclipses are not a daily occurrence, so our ancestors had to find some other phenomenon of short duration that could be timed by simple means every day. Sunset and moonrise made possible for them to use the principle just explained and find more or less precisely how far away they had moved since they had left home port or had passed some marker that was calculated for sunset and moonrise in their tables. Such astronomical tabulations written in cuneiform script have been found by the thousands on clay tablets in archaeological excavations in Mesopotamia.

With the help of these timetables, ancient navigators could easily determine their longitude by using every 2 minutes of sunset-moonrise difference for 15 longitude degrees of travel since the start of the voyage. If, for instance, the trip had started in Alexandria going west and the local sunset-moonrise difference in the open sea was 54 minutes instead of 48 minutes for the same day in Alexandria, the ship had to be as far west as the Canary Islands, 45
^°
west of Alexandria. When at the same time the astrolabe reading indicated a latitude of 28
^°
, the captain would order the lookout on top of the mast and the helmsman to take extra precautions because These readings told him that his ship was in between the Canary Islands.

If all of this sounds complicated to the uninitiated, believe me, it is not. Such checks and comparisons were entirely within the capabilities of our ancestors who figured even much more complicated movements of celestial bodies, like the cycles of conjunction of Jupiter and Saturn and the precession of the equinoxes.

The Sun and the Moon are exactly in line with Earth every 28.885 days. This period is called the ecliptic lunar month, because it is the minimum interval between two solar eclipses, sometimes followed by a lunar eclipse two weeks later when our planet, passing between the Sun and the Moon, throws its shadow on the latter. The average interval between two solar eclipses is 173.310 days. Whether or not these events will occur at all or whether there will be total or partial eclipses depends on complicated movements within the celestial vault that are well understood and present no problems to astronomers. I will skip the procedure of these calculations here because this book has too many numbers already.

Astronomers who specialize in calculating eclipses have made up tables for thousands of years in the past and the future, showing the dates, hours, and zones of visibility for all eclipses around the world. These modern tables are very useful to archaeologists and historians for checking the dates of certain past events described as having occurred during eclipses. For instance, it is one way to confirm that King Herod died on 13 March, in the year 4 BC, since historical documents mention a lunar eclipse on the day when he passed away.

Some eclipses have a history of their own. Such is the oldest recorded darkening of the Sun, in China, about 4,000 years ago on 26 April, 2137 BC. Two official astrologers of Emperor Chung Kang, who were paid mainly to predict eclipses so that the population could be told in advance not to panic, got stone drunk on rice wine on this day and forgot to give the warning. Neither could they, as the custom required, stand up to shoot arrows at the monster devouring the Sun. So the two culprits, Ho and Hsi, were decapitated on the spot, and since that time Chinese astrologers drink nothing but water on days when eclipses are expected.

Another famous solar eclipse took place on a battlefield in Lydia where, on 9 October, 583 BC, the Medes and the Lydians, after five years of war had lined up for the final attack at sunrise. The Sun rose in a blue sky and disappeared in a black shadow. The combatants laid their swords aside and promised each other never to fight again. To make sure that the promise would be kept, each king married the other's daughter. Peace was kept for several generations, as long as this historic eclipse was remembered.

The knowledge of precise dates for eclipses of the past has advantages for scientists who study the biblical events and try to rectify obvious errors. For example, we read in Amos VIII: "I will make the Sun disappear at noon and I will cover the earth with shadows on a clear day." This is the perfect description of a solar eclipse, but most Bibles note 787 BC as the year when this event took place. Our tables show that this date is an error because the only solar eclipse around that time that was visible in Samaria, then the capital of Israel, happened on June, 763 BC, or twenty-four years later than the Bible annotators tell us. Besides, when this time adjustment is applied to other dates of biblical events, these dates coincide perfectly with the dates given by Egyptians in their chronicles.

But let's return to navigation. We know now for certain that even before the chronometer was invented, the ancient mariners using lunisolar tables and hourglasses could, whenever the moon was visible, determine their longitude within one degree, or sixty nautical miles. This is remarkable accuracy considering the errors later
navigators report making
even long after the chronometer had come into common usage.

In 1703 French mariner Rene' Duguay-Trouin was leading his ships for nine days through thick fog along the Dutch coast and tried desperately to keep track of his longitude with hourglasses and pocket watches. When Sun was sighted on the tenth day and readings of precise solar time made, the error of the sand hourglass timing was eleven hours and the difference that the pocket watches had accumulated was even greater.

The Solomon Islands were discovered by Spaniards in 1567 and carefully charted by solar sightings, but for two hundred years after nobody could find them, although this chain of islands stretches for over 1,500 miles in the Pacific. When by accident the Solomon Islands were rediscovered in 1767, all maps of the Pacific had to be changed because the first entry had been false. The same thing happened to Pitcairn Island. Fletcher Christian, the chief of the mutinous crew of the British ship
Bounty,
arrived there in 1789 and found that his refuge was off by several hundred miles from the spot where it was shown on the nautical maps. This was the reason why he decided to stay there. He was proven right in his assumption that the British Admiralty, using its own erroneous maps, would not find him.

All these examples show that during the Christian era the great skill of navigation which was demonstrated by our distant ancestors, slowly deteriorated. In the last couple of centuries, all kinds of silly proposals were made on how to improve navigation over wide oceans. None of them was so simple and efficient as the ancient moonrise tables. Some scientists proposed to measure the apparent angle between the Moon and certain stars that is different at different points of the globe; but the precision needed for such measuring makes it impractical for small instruments aboard a ship. It was even proposed that a satellite of Jupiter be observed for calculation of longitude at sea, an operation that I certainly would not like to be in charge of, especially when Jupiter is above us only in daytime and no pair of binoculars usable aboard a ship will show its moons.

Another fanciful proposal without any practical merit was to anchor ships on each meridian and let them shoot coloured flares every hour on the hour to indicated longitude to vessels passing by. But how do you measure exact distance over open water with the techniques that were at the disposal of seamen in the nineteenth century? And how do you anchor a ship in mid-Pacific? The well-known American writer of the last century, Edward Everett Hale, wrote a science-fiction story called 'The Brick Moon', in which he came up with a brilliant idea, and established himself as the inventor of the navigation satellite, the backbone of modern navigation today.

In Hale's book, a manmade moon constructed of bricks was orbiting our globe with the precision of a pendulum, every ninety minutes. The time of passage of this satellite through the local meridian, gave the exact longitude, much as a passenger on a train that is exactly on time, could tell where the train is just by looking at his watch and timetable, not out the window.

Today, the navigator of any ship lost in the thickest fog can easily determine his positon within a few hundred feet, an achievement made possible by the three Transit satellites which the US Navy in 1961 placed 120 apart on the same polar orbit and circling the Earth every ninety minutes. Each parallel is crossed every thirty minutes, and because of the rotation of our globe, each following passage is 7 1/2
^°
further west than the preceding one.

After three passages of the satellites, the ship's navigator can trace a very small triangle on his chart and knows that he is within these limits. The principle is very simple and only an hour is needed to do the job. A robot calculator using the Doppler-Fizeau effect usually does all the work. When the satellite passes, it emits a crystal-controlled frequency, a stable tone that changes as the whistle of a train changes when it passes by. The frequency of the tone received gets higher as the source moves towards you and drops as it moves away.

I know the Transit satellites very well indeed, because the first three that were put into orbit were equipped with spherical spiral antennas that I invented and described in detail in
Aviation Week
on 25 August, 1958. I also applied for a US patent; but it was never issued to me for this invention, because then the Navy would have been forced to pay me a compensation for the unauthorized use of this improvement in electronics. NASA also tried to use the same tactics with most inventors. They had to change this course rapidly, however, because NASA did not have quite the pull of the Navy; and everyone
who came up with a good invention kept it under wraps until a patent was issued to him, which normally takes at least two full years. NASA could not wait that long; and therefore decided to recognize the rights of the inventors.