Nimrud lens
Encyclopedia
The Nimrud lens is a 3000 year old piece of rock crystal, which was unearthed by Austen Henry Layard
at the Assyrian
palace of Nimrud
, in modern-day Iraq
. It may have been used as a magnifying glass
, or as a burning-glass
to start fires by concentrating sunlight. Assyrian craftsmen made intricate engravings, and could have used such a lens
in their work. The discoverer of the lens noted that he had found very small inscriptions on Assyrian artefacts which he suspected had been achieved with the aid of a lens.
The slightly oval lens has been roughly ground and has a focal point
about 4.5 inches (114.3 mm) from the flat side. The surface of the lens has twelve cavities that were opened during grinding, which would have contained naptha or some other fluid trapped in the raw crystal. The lens is said to be able to focus sunlight although the focus is far from perfect. Because the lens is made from natural rock crystal the material of the lens has not deteriorated significantly over time.
Italian scientist Giovanni Pettinato of the University of Rome has proposed that the lens was used by the ancient Assyrians
as part of a telescope
, and that this explains their knowledge of astronomy
(see Babylonian astronomy). Experts on Assyrian archaeology
are unconvinced, doubting that the optical quality of the lens is sufficient to be of much use. The ancient Assyrians saw the planet Saturn
as a god surrounded by a ring of serpents, which Pettinato suggests was their interpretation of Saturn's rings as seen through a telescope. Other experts say that serpents occur frequently in Assyrian mythology, and note that there is no mention of a telescope in any of the many surviving Assyrian astronomical writings.
The Nimrud lens is on display in the British Museum
.
Austen Henry Layard
Sir Austen Henry Layard GCB, PC was a British traveller, archaeologist, cuneiformist, art historian, draughtsman, collector, author, politician and diplomat, best known as the excavator of Nimrud.-Family:...
at the Assyrian
Assyria
Assyria was a Semitic Akkadian kingdom, extant as a nation state from the mid–23rd century BC to 608 BC centred on the Upper Tigris river, in northern Mesopotamia , that came to rule regional empires a number of times through history. It was named for its original capital, the ancient city of Assur...
palace of Nimrud
Nimrud
Nimrud is an ancient Assyrian city located south of Nineveh on the river Tigris in modern Ninawa Governorate Iraq. In ancient times the city was called Kalḫu. The Arabs called the city Nimrud after the Biblical Nimrod, a legendary hunting hero .The city covered an area of around . Ruins of the city...
, in modern-day Iraq
Iraq
Iraq ; officially the Republic of Iraq is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....
. It may have been used as a magnifying glass
Magnifying glass
A magnifying glass is a convex lens that is used to produce a magnified image of an object. The lens is usually mounted in a frame with a handle ....
, or as a burning-glass
Burning-glass
A burning glass or burning lens is a large convex lens that can concentrate the sun's rays onto a small area, heating up the area and thus resulting in ignition of the exposed surface. Burning mirrors achieve a similar effect by using reflecting surfaces to focus the light...
to start fires by concentrating sunlight. Assyrian craftsmen made intricate engravings, and could have used such a lens
Lens (optics)
A lens is an optical device with perfect or approximate axial symmetry which transmits and refracts light, converging or diverging the beam. A simple lens consists of a single optical element...
in their work. The discoverer of the lens noted that he had found very small inscriptions on Assyrian artefacts which he suspected had been achieved with the aid of a lens.
The slightly oval lens has been roughly ground and has a focal point
Focus (optics)
In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge. Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by...
about 4.5 inches (114.3 mm) from the flat side. The surface of the lens has twelve cavities that were opened during grinding, which would have contained naptha or some other fluid trapped in the raw crystal. The lens is said to be able to focus sunlight although the focus is far from perfect. Because the lens is made from natural rock crystal the material of the lens has not deteriorated significantly over time.
Italian scientist Giovanni Pettinato of the University of Rome has proposed that the lens was used by the ancient Assyrians
Assyrian people
The Assyrian people are a distinct ethnic group whose origins lie in ancient Mesopotamia...
as part of a telescope
Optical telescope
An optical telescope is a telescope which is used to gather and focus light mainly from the visible part of the electromagnetic spectrum for directly viewing a magnified image for making a photograph, or collecting data through electronic image sensors....
, and that this explains their knowledge of astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
(see Babylonian astronomy). Experts on Assyrian archaeology
Archaeology
Archaeology, or archeology , is the study of human society, primarily through the recovery and analysis of the material culture and environmental data that they have left behind, which includes artifacts, architecture, biofacts and cultural landscapes...
are unconvinced, doubting that the optical quality of the lens is sufficient to be of much use. The ancient Assyrians saw the planet Saturn
Saturn
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...
as a god surrounded by a ring of serpents, which Pettinato suggests was their interpretation of Saturn's rings as seen through a telescope. Other experts say that serpents occur frequently in Assyrian mythology, and note that there is no mention of a telescope in any of the many surviving Assyrian astronomical writings.
The Nimrud lens is on display in the British Museum
British Museum
The British Museum is a museum of human history and culture in London. Its collections, which number more than seven million objects, are amongst the largest and most comprehensive in the world and originate from all continents, illustrating and documenting the story of human culture from its...
.