Sunlight and time, colour and space in the ancient history of mankind Richard Kittler and Stanislav Darula Institute of Construction and Architecture SAS Bratislava, Slovakia

Phylogeny – evolution of living organisms through the ages while adapting to their environment Inherited qualities stored in DNA sequences are transmitted by cells during endless generations Evolution of eyes in apes and homonids about 30 – 40 million years ago Gregory, R.L.: Eye and brain. BAS Printers Ltd., Wallop, 1966,

Human eyes Space and search human visual field Retina structure: Ganglion cells – circadian rythm Rods – scotopic (night) vision Cones – photopic (daytime) vision Gregory, R.L.: Eye and brain. BAS Printers Ltd., Wallop, 1966,

Homonid environment Equator 10° N Equatorial climate: - yearly temperature equlity/comfort - affluence of greenery - equal day and night time Gore, R.: The first steps. National Geographic, 191 (1997), 2, and map.

Sun as an energy source Sun paths at the equator In any day sun shadows indicate E – W orientation at the equator but in equinox days at any locality In equator localities the day is halved to equal day and night time at equinox day

Circadian rythms Photorecepting eye ganglion cells control daily rythms: - stimulating: -- alertness and human activity -- body performance (temperature, urine production, adrenaline etc) - influencing: -- tiredness due to production of the sleeping hormon melatonin -- sleeping/waking pattern Stoer, G.W.: Light and health in the workplace. NSVV Netherlands, 2005.

Solar radiation and sunlight Extraterrestrial sun radiation spectrum contains: Visible range Wavelengt h in nm Intensity in W/m 2 nm Visible part Ultraviolet radiation in three ranges -UV killing bacteria max. at 254 nm, filtered fully by the ozon layer produced by greenery, -UV B (Dorno rays) max. at 275 nm with antirachitic effect in D vitamin production under high sun and clean atmosphere, -UV A max. at 350 nm with erythemal effect on sun tanned skin, Visible radiation with monochromatic colours, Infrared thermal radiation Solar constant in the whole energy spectrum 1367 W.m -2 Luminous solar constant klx

Daytime adaptation Greenery utilises sunlight mostly at 450 and 670 nm for photosynthesis Daytime vision is most sensitive at 555 nm, i.e. reflected from greenery Gregory, R.L.: Eye and brain. BAS Printers Ltd., Wallop, 1966,

Eye movements -overall luminance adaptation, visual search, overview with accomodation to distances -saccadic reflexes with detail reading for information clues Scanning individual environment and space identifying objects: Re-created fossil skull of Australopithecus afarensis Jarbus, A.L.: Rol dviženii glaz v procese zrenija (Task of eye movements in visual process). Nauka Moskva, 1965

Human migration – new challenges Route orientation Diverse environment seasonal sunpath reduced solar energy seasonal temperature humidity changes Food availability Shelter protection cave tent building Fire

Human activities, knowledge, culture from mammoth tusk Venus Tools – sticks, clubs, spears -stones (boulder fit to hand) -bones (needles Venuses) Norvegian reindeer with guts (Kloftefoss) Hunting dangers and spear targets Lastcaux cave, France Jelínek, J.: Veľký obrazový atlas pravekého človeka (Great picture atlas of ancient man. Mladé letá 1980

Conclusions In spite of civilisation achievements: - sunlight and skylight influence our body functions - - inherited phylogenetic qualities of human eyes predetermine the time and space orientations - - daylight mediates visual information and adjustment of individuals to their environment - - daytime illumination enables activity and creativity - changes in day and night time predetermine - - everyday circadian rythms of alertness and rest - - dynamic changes in illuminance levels are training visual adaptation system in men (the eye muscles, pupil and saccadic motion reflexes) - - variety of sunlight and skylight with directional and colour changes improve sight adaptation and acomodation

- space location of the country and urban environment create exterior life conditions - - longer than 5 million years of hominid phylogeny in equatorial locality overwhelms recent conditions, e.g. electric lighting - colour enhances the quality of visual information and overall comfort - - with better recognition of objects and details - - with aesthetic emphasis and wellness of interiors Conclusions

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