Relative Illumination

There is an exhibit at a local Science Centre. Two participants sit facing one another. A glass plate is between them. There is a knob which controls the relative illumination on each side of the glass.

When the illumination on one side is much greater than on the other, much more light is reflected from this side of the glass, than is transmitted from the low light side. The participant on this bright side will see the reflection of her or him self. The person on the opposite side, the side with lower illumination, will see the other person, since much more light is transmitted through the glass from the other person, than reflected from this side.

Gradually changing the relative brightness brings a gradual change from seeing only oneself, to seeing the light reflected from both the other and oneself, to seeing only the other. On an intermediate setting one sees both the light reflected from one's self and the light transmitted through the glass from the other.

More light on oneself <–> Light on both <–> More light on the other

I knocked.
"Who is there?"
"I"
The door was not opened.

I knocked.
"Who is there?''
"Thou"
"Enter".

Interpretation of a poem by Mevlana Rumi (1207 -1273)

My addition:

One day I knocked and one day you.
Who is here?
"Us!"
"Let's go out!"

:) Bev