Ollantaytambo, as well as other sites, ancient stone blocks were found strapped together by copper links. The question arose, why soft copper for such massive stone blocks? Especially with the stones precision of placement. The belief of local smelting pouring into the groves is because of the microscopic marks embedded in the straps imitate the corollary marks in the stone. But some show no convex due surface tension in casting process and no cast line caused by the crack between the stone blocks.
The discolored outer surface layer of stone suggests maybe a softening process that later hardens the stone permitting the ready formed copper strips as to why the flat top nature and absence of inter-block cast line.

It has suggested it all was for earth bonding the stones electrically.

To soften and pour stone today is one directional-soft to hard, concrete.
Then maybe suggested with igneous rocks hard to soft again over coming the covalent that bind atoms together. Would make clay to brick look like child’s step to adults knowing.

If stones cracks were filled with pitch and resin, they would be electrically insulated from each other.

If not, electrically bonded to earth. That is the absence of gaps.

In humans retinas, a light sensitive area of the eye converts light into electrical signals that travel down optic nerve into hypothalamus gland, aka the body’s biological clock!

Each day light enters the brain. Each night the gland sends signals to the pineal gland. The amount of light determines the amount of melatonin production.