DavidMawer wrote:
"The main sauce of light for our planet is the Sun and yet we are unable to look at it, in other words we cannot see the light direct from the Sun."
The reason for this is because of the intensity of the sun. A photon is considered the elementary particle responsible for electromagnetic phenomena. It is the carrier of electromagnetic radiation of all wavelengths, including gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. Visible light is considered to be a portion of the electromagnetic spectrum in the range of about 380 to 750 nm in air. The corresponding wavelengths in water and other media are reduced by a factor equal to the refractive index.
The refractive index of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium.
DavidMawer wrote:
"Nor can we see it indirectly because we can’t see the light from the Sun striking the surface of the Moon even though at night it must be passing by the Earth in order for the moon to shine down on us."
The reason why you can't see the light of the sun reflecting off the moon directly is because the sun is on the other side of the planet.