Viking Compass: Sun Stones Riddle
Viking Compass: Sun Stones Riddle
Anonim

For many years, scientists have tried to determine how the Vikings managed to make long sea voyages. After all, as you know, for these desperate Scandinavian sailors with their compact maneuverable ships, the drakkars did not have much difficulty in overcoming a path of about 2500 kilometers from the coast of Norway to Greenland, without deviating from the course, that is, almost in a straight line!

Not to mention the fact that it is the Vikings, led by Leif Eriksson, who are considered the real discoverers of America.

There was no question of any magnetic navigation in those days, sailors had to literally rely on the will of the sky - to navigate by the position of the sun, moon and stars, but the northern waters do not differ in mild climate and sunny weather, clouds and fogs there are the most common occurrence. How did the Vikings manage to navigate in such conditions?

This question remained unanswered until 1948, when the legendary disc Uunartok was discovered - a compass, which, according to the sagas, in combination with a certain solstenen, a magical solar crystal, served as the main navigation tool of northern sailors. But this discovery posed more questions than answers.

In the records of the modern Viking era, and later written sources, you can find mention of a fairly accurate, despite the external simplicity, compass, which allowed the warrior travelers to determine the direction of the ship in any weather.

So what is special here, you ask. However, for the early Middle Ages, such opportunities were akin to witchcraft. It was almost impossible to navigate the open sea without seeing the heavenly bodies, given the level of navigation that existed at that time.

Nevertheless, the Vikings, who were considered dirty pagans in the Christian world of the 9th-11th centuries, who did not even have their own state, succeeded with enviable success.

What was the Viking compass and how did it work? A fragment of a disk from the Greenland fjord of Uunartok allowed researchers to determine that the Viking compass was, in fact, a complex sundial with marks indicating the cardinal points and carvings corresponding to the trajectories of the shadow from the gnomon (the central tongue of the sundial) throughout the daylight hours in summer. solstice and equinox.

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According to the experimental data obtained by the researcher of this artifact Gabor Horvath from the University of Otvos in Budapest, the accuracy of the clock was very high: if you position the disk in sunny weather in a certain way - so that the shadow of the gnomon coincides with the corresponding notch - you can navigate by cardinal points with an error of no more than 4 °.

True, in the writings of Croat, an amendment is made to the fact that the Uunartok disk is most effective during the period from May to September and only at latitude 61 °. In other words, the compass watch was used exclusively in the summer, when the Vikings made their campaigns, and provided the most accurate navigation on the way from Scandinavia to Greenland through the North Atlantic Ocean - on the most frequent and longest route in open waters.

However, the study of the disc of Uunartok alone did not give an answer to the question of what kind of mystical "sun stone" that gave the Vikings a reference point when our star was not visible in the sky.

The credibility of the Vikings' use of the mythical stone for navigation has long been questioned. Skeptics even believed that the "sun stone" was an ordinary piece of magnetic iron ore, and the glow and the appearance of the sun from behind the clouds were just an invention of the storytellers.

But the researchers, who studied this problem in more detail, came to the conclusion that everything is not so simple, and even formulated the theoretical principle of the method of northern sailors.

Back in 1969, the Danish archaeologist Thorkild Ramskou suggested that the "sunstone" should be sought among crystals with polarizing properties. His theory is also indirectly confirmed by the text of the "Saga of Olaf the Saint", recorded in the 13th century in the famous collection of Scandinavian sagas "The Circle of the Earth" through the efforts of the Icelandic skald Snorri Sturluson.

The text of the saga reads: “… The weather was cloudy, it was snowing. Saint Olaf, the king, sent someone to look around, but there was no clear point in the sky. Then he asked Sigurd to tell him where the Sun was. Sigurd took the sunstone, looked up at the sky and saw where the light came from. So he found out the position of the invisible sun. It turned out that Sigurd was right."

Having studied all possible minerals common in the fields of activity of the ancient Scandinavians, scientists came to the conclusion that three minerals can be considered the main candidates for the role of the notorious solstenen - tourmaline, iolite and Icelandic spar, which is one of the varieties of transparent calcite.

There was little left to do: to determine which of these minerals would turn out to be "the one", because all of them were available to the Vikings.

A discovery made in 2003 during the investigation of the wreck of an Elizabethan ship that sank in 1592 near the Norman island of Alderney in the English Channel helped shed light on the problem of the true "sun stone". In the captain's cabin, a translucent, whitish block of polished stone was discovered, which turned out to be nothing more than Icelandic spar.

This discovery was of great interest to French physicists from the University of Rennes Guy Ropars and Albert Le Floch, who conducted a series of experiments with Icelandic spar. The results, published in 2011, exceeded all expectations.

The principle of using the mineral is based on birefringence, a property that was described back in the 17th century by the Danish physicist Rasmus Bertolin. Thanks to him, the light that penetrates into the structure of the crystal is split into two components.

Since the rays have different polarizations, the brightness of the images on the back of the stone depends on the polarization of the original light. Thus, by changing the position of the crystal so that the images acquire the same brightness, it is possible to calculate the position of the sun even in cloudy weather, or provided that it has sunk below the horizon no more than 15 minutes ago.

Two years later, the physics and mathematics journal of the Royal Society of London, Proceedings of the Royal Society, published an equally bold article in which it was said that a block of Icelandic spar found on a sunken ship can rightfully be considered a trustworthy navigation device that the Vikings used in their sea wanderings.

It is not surprising that the rather bold message about the established geological origin of the "sun stone" from the Old Icelandic sagas, which could not be confirmed by archaeological data of the 9th-11th centuries, was met with a wave of criticism.

According to militant skeptics, who never accepted the theory of "polarimetric navigation" of the Vikings, it is not necessary to invent complex methods to determine the position of the sun in cloudy weather - for this, the rays breaking through the veil of clouds are enough.

And the tales of the mythical "sun stones" are inventions of skalds who want to extol the knowledge and skills of "dirty pagans", and nothing more.

In response to these insinuations, Gabor Horvat suggested that skeptics try to determine the position of the sun literally by "pointing a finger at the sky." The subjects were offered several panoramas of the sky at different times of the day and with different degrees of cloudiness, on which they had to mark with the mouse the place where, in their opinion, the sun was.

As the experimenters summarize diplomatically, as the cloud density increases, the average statistical differences between the imaginary and actual location of the star increase significantly.

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In other words, the critics have failed miserably. The Vikings really needed an additional navigation device - and they not only found it, but also developed a rather ingenious method of using it.

The joint efforts of Horvath, Ropar and Lefloch experimentally confirmed that the Viking compass, previously considered only an invention of storytellers, not only existed in reality, but also made it possible to determine the route in open waters with amazing accuracy.

Moreover, the find from a ship that sank to the bottom in the 16th century proves that the method of orientation with the help of the "sun stone", known to navigators of ancient Scandinavia, fully justified itself even in the days of magnetic navigation, despite the 500-year-old abyss separating the Viking Age and Elizabethan England.

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