Grappling with shadows in the fourth dimension

Notestoponder asked a simple question: “can someone explain the 4th dimension”. The responses she got were disappointing. Standard high school explanations such as “time is the fourth dimension”, or “imagine color or transparency” as a fourth dimension.

Fourth dimension for skeptics

Gotta share this. I did a mind bending experiment the other day. I was playing around with the shadow tree sculpture and came with the odd idea to replace the white LED at its center by a green and a red led.