Re: a link to some interesting illusions

[Larry Woolf <Larry.Woolf@GAT.COM>]

At 10:09 AM -0700 2/4/2003, Robert Cohen wrote:
> I still have a question about "yellow is a mixture of
> green and red light".  I agree that the perception
> of yellow CAN BE a mixture of green and red light but
> couldn't yellow also be "just yellow" (i.e., a single
> frequency that excites the red/green cones in just
> the right way for us to perceive yellow)?

Yes. Our perception of a given color can be obtained with many different
spectra entering our eye.  Yellow can be observed with a single wavelength
as well as by a mixture of red and green light.  In fact, I don't really
like their answer because in the case of a rainbow, we are seeing the
colors due to dispersion, in which different wavelengths are observed, not
mixtures of red and green light.  So their answer, in this case, leaves a
lot to be desired.

Larry Woolf,General Atomics,San Diego, CA 92121; Phone: 858-526-8575; FAX:
858-455-8568