[Physics] Why does a red object appear dark in yellow light

Question

"red objects appear dark in yellow light" as my text says…————(1)

but what I think is that..

• we see colour of an object because it reflects that colour of light and absorbs all others so when yellow would fall on originally red object it would appear dark ( to which I agree)

But then the next statement confuses me
" the red color is scattered less but this is not the reason for the (1) phenomenon to happen"

I thought why would it be so because if that light was less scattered it was absorbed mostly and hence we were not able to see that then shouldn't that be a correct explanation?

Answer 1

Have a look at Rayleigh scattering. An electromagnetic wave with a longer wavelength scatters less. Red has the longest wavelength in the visible light's spectrum and so it is scattered the least.

Now what your text says is that reflection has nothing to do with the fact that red light scatters the least and thus less scattering of red is not the reason why red objects appear dark in yellow light. Your understanding is right.

We see the color of an object because it reflects that colored light and absorbs all others so when yellow would fall on originally red object it would appear dark (to which I agree)

This is true and you are right, your text is also right. You are just confusing between reflection and scattering perhaps. Read up on scattering and it should be clear. Hope this helps.