Shipwreck crystal might be rare Viking navigational aid
Icelandic calcite believed to be found in 16th century wreck in the English Channel
The Associated Press
Posted: Mar 8, 2013 3:49 PM ET
Last Updated: Mar 8, 2013 4:24 PM ET
A rough, whitish block recovered from an Elizabethan shipwreck may be a sunstone, the fabled crystal believed by some to have helped Vikings and other medieval seafarers navigate the high seas, researchers say.
In a paper published earlier this week, a Franco-British group argued that the Alderney Crystal — a chunk of Icelandic calcite found amid a 16th century wreck at the bottom of the English Channel — worked as a kind of solar compass, allowing sailors to determine the position of the sun even when it was hidden by heavy cloud, masked by fog, or below the horizon.
'You don't have to understand how it works.Using it is basically easy.'—Albert Le Floch, University in Rennes
That's because of a property known as birefringence, which splits light beams in a way that can reveal the direction of their source with a high degree of accuracy. Vikings may not have grasped the physics behind the phenomenon, but that wouldn't present a problem.
"You don't have to understand how it works," said Albert Le Floch, of the University in Rennes in western France. "Using it is basically easy."
Vikings were expert navigators — using the sun, stars, mountains and even migratory whales to help guide them across the sea — but some have wondered at their ability to travel the long stretches of open water between Greenland, Iceland, and Newfoundland in modern-day Canada.
Le Floch is one of several who've suggested that calcite crystals were used as navigational aids for long summer days in which the sun might be hidden behind the clouds. He said the use of such crystals may have persisted into the 16th century, by which time magnetic compasses were widely used but often malfunctioned.
Le Floch noted that one Icelandic legend — the Saga of St. Olaf — appears to refer to such a crystal when it says that Olaf used a "sunstone" to verify the position of the sun on a snowy day.
But that's it. Few other medieval references to sunstones have been found, and no such crystals have ever been recovered from Viking tombs or ships. Until the Alderney Crystal was recovered in 2002, there had been little if any hard evidence to back the theory.
Many specialists are still skeptical. Donna Heddle, the director of the Center for Nordic Studies at Scotland's University of the Highlands and Islands, described the solar compass hypothesis as speculative.
"There's no solid evidence that that device was used by Norse navigators," she said Friday. "There's never been one found in a Viking boat. One cannot help but feel that if there were such things they would be found in graves."
She acknowledged that the crystal came from Iceland and was found near a navigation tool, but said it might just as easily have been used as a magnifying device as a solar compass.
Le Floch argued that one of the reasons why no stones have been found before is that calcite degrades quickly — it's vulnerable to acid, sea salts, and to heat. The Alderney Crystal was originally transparent, but the sea water had turned it a milky white.
Le Floch's paper — written with Guy Ropars, Jacques Lucas, and a group of Britons from the Alderney Maritime Trust — appeared Wednesday in the Proceedings of the Royal Society A.
Top News Headlines
- 3 more suspects arrested in slaying of U.K. soldier
- British police investigating the savage killing of an off-duty soldier in London have arrested three more suspects. more »
- Hockey Canada votes to ban bodychecking in peewee hockey
- Hockey Canada's board of directors voted to eliminate bodychecking from peewee-level hockey on Saturday in Charlottetown. more »
- Neil Macdonald: How serious is Obama about curbing the drone surge?
- In a key speech this week, the U.S. president set out a host of supposed new safeguards for America's controversial practice of remote-controlled rough justice. But as Neil Macdonald writes, the underlying rationale for drone use has not fundamentally changed. more »
- Ontario man lost in Australian mountains has survival skills
- The sister of an Ontario man who disappeared in Australia's Snowy Mountains nearly two weeks ago says she remains hopeful he will be found, partly because of his training as a Canadian Forces reservist. more »
Latest Technology & Science News Headlines
- 1976 Apple computer sells for $668,000
- An auctioneer says one of Apple's first computers — a functioning 1976 model — has been sold for a record $668,000 US. more »
- 3D printers give rise to 'desktop manufacturing'
- Customizable objects from plastic dollhouse furniture to medical prosthetics can now be designed and printed out by almost anyone at the press of a button, and is going to lead to an 'explosion of new stuff,' predicts author Chris Anderson. more »
- Google Street View captures Galapagos Islands
- Few have explored the remote volcanic islands of the Galapagos archipelago, an otherworldly landscape inhabited by the world's largest tortoises and other fantastical creatures that inspired Charles Darwin's theory of evolution. more »
- King Richard III buried in 'untidy' grave
- New information has surfaced in the odd tale of the British king buried in a car park. King Richard III's remains, which were discovered August under a parking lot in Leicester, England, were laid to rest in a grave researchers are now saying was "badly prepared" and "untidy." more »
Bob McDonald's Blog
- Chris Hadfield: The gravity of gravity May. 17, 2013 9:58 AM After five months of being Superman and a media superstar, Canadian astronaut Chris Hadfield is now beginning the challenging task of adapting his mortal body and brain to life back on Earth.
- McDonald's CEO chastised by 9-year-old B.C. girl
- Will Rob Ford's supporters leave Ford Nation?
- Toronto Mayor Rob Ford denies using crack cocaine
- Dog snared on baited hooks near Vancouver's Grouse Grind trail
- Washington police blame bridge collapse on Alberta trucker
- 3 more suspects arrested in slaying of U.K. soldier
- Wallin may be forced to repay thousands in travel expenses
- Canada ranks 3rd last in paid vacations
- Toronto mayor's brother says he never dealt drugs