Firelight transformed how early humans utilized their rocky dwellings.
(CN) --- Long before the Dark Ages, a longer, darker period ruled much of life on earth, including Neanderthals and early humans.
Now scientists are shedding light on this time when life was lived in caves during the cold, dreary winter months.
To brighten their days and nights, groups during the Paleolithic period relied on artificial light sources to illuminate the deep, dark caves they used for shelter. But such lighting did more than allow them to cook and move about. Depending on the source, this lighting enabled the first symbolic behavior that thousands of years later would be enshrined as art.
A team of researchers led by Mariángeles Medina-Alcaide from the University of Cantabria, Spain, has recreated the three common types of Paleolithic lighting systems --- torches, grease lamps and fireplaces --- to better understand how cave dwellers during this time may have traveled, lived and created paintings that continue to inspire modern humans.
“The artificial lighting was a crucial physical resource for expanding complex social and economic behavior in Paleolithic groups, especially for the development of the first palaeo-speleological explorations and for the origin of art in caves," the study authors wrote.
Published in the journal PLOS ONE, the study documents how Medina-Alcaide and her colleagues used archaeological evidence of lighting remains found in several Paleolithic caves featuring cave art in southwest Europe to replicate the types of artificial lighting presumably used by the original human cave dwellers.
The team discovered the extent to which light intensity and duration, area of illumination and color temperature influence how a cave can be used by its inhabitants.
The team conducted experiments in Isuntza 1 Cave in the Basque region of Spain utilizing archaeological evidence from similar Paleolithic caves to recreate the kinds of torches, lamps and fireplaces the original inhabitants would likely have used to live in such caves. Their experiments included five torches made from ivy, juniper, oak, birch and pine resins; two stone lamps using animal fat; and a small fireplace with oak and juniper wood.
Each source of light had its advantages and drawbacks.
Torches have the greatest light intensity, are easily transportable and don’t dazzle the eyes of the person carrying them. But they also emit high volumes of smoke and burn out quickly, limiting the time a person could explore a cave without running out of light.
In contrast, grease lamps burn longer and produce less smoke but produce less light and dazzle the human eye, making traveling difficult in darkness.
Fireplaces produced excessive smoke and were stationary, limited their usefulness to anyone hoping to explore a cave’s depths.
Complicating matters is the fact that all of these combustible light sources are influenced by temperature and humidity within the cave.
To verify their findings, researchers applied the estimated luminous data of a Paleolithic cave with corresponding rock paintings (Atxurra in northern Spain) in 3D through GIS technology to understand the archeologic implications of illumination in Paleolithic underground activities.
The authors hope their work deepens an understanding of what it may have been like to access the darkest parts of inhabited caves, especially in order to create art.
“Our experiments on Paleolithic lighting point to planning in the human use of caves in this period and the importance of lighting studies to unravel the activities carried out by our ancestors," they wrote.
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