We represent light by a ray. Again,we know light which is emitted from the sun has all seven colors in them,hence again seven light rays. So doesn't it mean that that light is again composed of $7$ rays? Why do we represent it by a single ray then? I beg pardon if this doesn't make any sense but i am confused by light having colours whereas each of those colours are again light waves.
$\begingroup$
$\endgroup$
2
-
4$\begingroup$ I'm sorry who told you that there are exactly seven colors? Like red orange yellow green blue purple pink? These are just the colors that humans have decided to name. In reality, there are infinitely many colors - look at a rainbow and see that it doesn't look like blocks of different colors (like the gay pride flag) it looks like a continuous change between colors with many colors in between. $\endgroup$– AXensenCommented Mar 26, 2023 at 11:45
-
$\begingroup$ please read the definition of a light ray in physics en.wikipedia.org/wiki/Ray_(optics) $\endgroup$– anna vCommented Mar 26, 2023 at 15:55
Add a comment
|
1 Answer
$\begingroup$
$\endgroup$
3
So doesn't it mean that that light is again composed of 7 rays?
No. There is no such thing as a specific countable number of light rays.
When we are doing ray optics the rays that we draw do not represent certain amounts of light. The rays represent the geometry. They are drawn perpendicular to the wavefronts since that is the direction of wave propagation, but they do not represent a certain amplitude, frequency, or phase. They are useful for figuring out the geometry of wave propagation when diffraction is negligible.
Once you have figured out the geometry then you can relate things like the intensity or phase at some target to the properties of the source. And the same relationship will hold regardless of the strength or spectral characteristics of the source except as those influence the properties of the optical elements along the ray.
-
1$\begingroup$ So when we say that this light is of this much wavelength,do we mean to say that we are seeing a certain colour of light with that range if wavelength? Also does that mean the light from sun has all kinds of wavelengths mixed in it? $\endgroup$– madnessCommented Mar 26, 2023 at 14:50
-
-
$\begingroup$ please read a relevant answer here, color is a many valued term in physics physics.stackexchange.com/questions/605951/… $\endgroup$– anna vCommented Mar 26, 2023 at 15:57