Posted: Aug 08, 2017 9:08 pm
by romansh
GrahamH wrote:
You are best placed to know what you mean by the question. It seems we probably agree. The question doesn't seem coherent to me. Your perception of red is not itself on the surface of the bus.

I have a perception of red (most of us do).
I have a perception that the bus is red (I think most of us do).
I think the bus exists and has a surface at least what passes for a surface.

I am trying to ask how accurate a representation is my red perception, of the bus's surface?

I am not claiming perception is on the surface.

Similarly we ask how accurate is a spectrophotometer 640 nm reading from the surface? Well it is the light reflecting from the surface. So what is the surface, red at the 640 wavelength?

And yet when I look at the bus surface, I definitely have a perception of redness. The surface is no more my perception than it is 640 nm. I am not trying to throw doubt on the physics ... just on my perception.