[ExI] Indoor or Underground Lighting

[Lee Corbin]

Suppose that I'm in a small cavern underground and that
I'm walking on a treadmill, so that I am not moving
relative to the walls of the cavern.

Does humanity at the present time have the ability to make
me think---at least when I'm looking down at my own
shadow---or to make it appear to me that I'm in natural
lighting, e.g., that there is something overhead that has
the same textures and frequencies of light, and that some
small part of an artificial sky has been well done?  (After
all, the simulation may be of me walking down an alley
in a big city.)

Thanks to anybody more knowledgable than I am on lighting
out there.

Lee