Researchers Test Ancient Lighting Systems to See How Paleolithic Humans Illuminated Their Caves | Archaeology, Paleoanthropology
Artificial lighting was a crucial physical resource for expanding complex social and economic behavior in groups of Paleolithic humans. Furthermore, the control of fire allowed the development of the first symbolic behavior in deep caves, around 176,000 years ago. In new research, scientists qualitatively and quantitatively characterized three lighting systems — torches, portable grease lamps, and fireplaces — used during the Paleolithic period to enter the depths of the caves.
Humans cannot see in the dark; therefore, they need light to access the deepest areas of caves — and these visits also depend on the type of light available.
In the new study, Dr. M ngeles Medina-Alcaide from the University of Cantabria and her colleagues used archaeological evidence of lighting remains found in several Paleolithic caves featuring cave art in Southwest Europe to experimentally replicate the artificial lighting systems presumably used by human cave dwellers.
The researchers conducted their experiments in Isuntza I Cave in Basque Country, Spain.
Their replicated lighting was based as much as possible on archaeological evidence found in similar Paleolithic caves, and included five replicated torches (made variably from ivy, juniper, oak, birch, and pine resins), two stone lamps using animal fat (bone marrow from cow and deer), and a small fireplace (oak and juniper wood).
They found that the different lighting systems all had diverse features, suggesting their likely selection and use across different contexts.
Wooden torches made of multiple sticks worked best for exploring caves or crossing wide spaces, since they projected light in all directions (up to almost 6 m in the experiments), were easy to transport, and didnt dazzle the torchbearer despite having a light intensity almost five times greater than a double-wicked grease lamp.
Torch light lasted for an average of 41 min, with the shortest-lived torch burning 21 min, and the longest burning 61 min.
The torches tended to function irregularly and required close supervision when burning — though they were easy to relight via oxygenation (moving the torch quickly side to side).
The authors found the main torch disadvantage was the amount of smoke production.
In contrast, grease lamps worked best for lighting small spaces over a long period — with a light intensity similar to a candle, they were able to light up to 3 m (or more if larger or multiple wicks were added).
Though grease lamps werent well-suited for transit due to their dazzling effect and poor floor illumination, they burned consistently and without much smoke for well over an hour, complementing the use of torches.
The team made one fireplace, a static system, which burned very smokily and was extinguished after 30 min.
The location was likely not appropriate due to air currents in the cave, the scientists said.
The practical insights and observations gained from their experimental replications are invaluable for a deeper understanding of what it may have been like to access the darkest parts of inhabited caves, especially in order to create art, and emphasize that future experimental lighting studies will be useful in continuing to unravel our ancestors activities in their caves.
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 paleo-speleological explorations and for the origin of art in caves, they concluded.
The results were published in the journal PLoS ONE.
M ngeles Medina-Alcaide et al. 2021. The conquest of the dark spaces: An experimental approach to lighting systems in Paleolithic caves. PLoS ONE 16 (6): e0250497; doi: 10.1371/journal.pone.0250497