The control of fire by early humans was a turning point in the technological evolution of human beings. Fire provided a source of warmth, protection from predators, a way to create more advanced hunting tools, and a method for cooking food. These cultural advances allowed human geographic dispersal, cultural innovations, and changes to diet and behavior. Additionally, creating fire allowed human activity to continue into the evening's dark and colder hours.
Claims for the earliest definitive evidence of fire control by a member of Homo range from 1.7 to 2.0 million years ago. Evidence for the “microscopic traces of wood ash” as the controlled use of fire by Homo erectus, beginning some 1,000,000 years ago, has wide scholarly support. Flint blades burned in fires roughly 300,000 years ago were found near fossils of early but not entirely modern Homo sapiens in Morocco.
The fire was used regularly and systematically by early modern humans to heat treat silcrete stone to increase its flake-ability for toolmaking approximately 164,000 years ago at the South African site of Pinnacle Point. Evidence of widespread control of fire by anatomically modern humans dates to approximately 125,000 years ago.They also used fire for light.
Infrared Light from Fire
The burning of wood (or other organic materials) releases energy in the form of infrared light. When you take a photo of someone with an infrared camera, what do you see? A heat “signature” that correlates (approximately) to their metabolic activity.
What is infrared light? It is a spectrum of light that we can’t see but that powerfully shapes our biology. You sense infrared light as “heat.” The heat you feel from the sun — that’s the sensation of infrared light. The feeling of heat you get when you put your hand close to an oven, toaster, or fire — that is also infrared light. The heat of another person’s body — infrared light again. Hot springs transfer heat to your body in the form of infrared light stored in the water itself. When you take a hot shower or hot bath, the same principle is at work.
Infrared light has been used for decades as a heat source for saunas. Before IR saunas, we had sweat lodges and traditional stone saunas. In traditional saunas and sweat lodges, stones absorb energy from either an electronic heating unit (in the case of a sauna) or a fire. The light is stored in the stones and gradually released during the sweat lodge or the sauna. Both methods use light to heal the human body.
And infrared light doesn’t just transfer “heat” to your body — it turns the water in your cells into batteries. This is likely why ancient cultures recognize the importance of fire, sweat lodges, and saunas, especially in winter.
It is not a coincidence that sitting down next to a fire is so comfortable. Firelight is natural and helps to manage melatonin production as well as keeping our circadian rhythms under control.
A fireplace or fire-pit isn’t just an ornamental detail of your home, and it’s a tool you can use to live a healthier life.