One Question

thn u consider the horizontal surface as the normal........may b! [1]

Possible Scientific Explanation : Because the incident ray and reflected ray are symmetric about the normal ...

Actual Baseless Explanation : Because some ultra-intelligent specimens of Homo Sapiens told it and we are carrying their legacy forward ! :P :P :P

@ Abhishek,

Shouldn't it be reflective ray?

When there is refraction, incident ray and refractive ray aren't symmetric about the normal.

That baseless explanation is a nonsense [3][3]

Oh yeah...It is reflected ray (edited!)

And Baseless explanations are always nonsense! :P

@ Vivek,

I think we measure the angle with respect to the normal because by doing so we can explain many phenomenon that happens in the nature due to reflection and refraction of light.

May be by measuring the angle horizontally we wont be able to explain those phenomenon so neatly. Or may be we'll be but only in the case of flat objects.

And in the case of reflection and refraction on spherical surface where surface is not horizontal we wont be able to explain all the things without having lots of assumptions.

So for keeping the things easy and clear we measure the angle w.r.t to normal.

You have just started optics, as you will move further you'll get everything.

Anyways if you wanna measure w.r.t horizontal, you are free to do so, Arey waah!!![3] you

toh actually got a topic for thesis, you do it Vivek and prove that all the phenomenons are

possible by measuring angle w.r.t to horizontal too. I know assumptions lene padenge but

physics mein toh bahut sare assumptions liye jate hain, tum thode aur le lo kya farak padta

hai.

Lastly

Defining the angle a ray makes with a line (the normal) is easier than defining the angle it makes with a plane (the tangent plane, to a surface that may be curved)

Hope this makes the things clear. [1]

WHAT DO YOU MEAN BY EASIER.are we engaged in time saving tactics or what.

experts reply.

By using the word easier I dont mean that you or we or others are engaged in time saving

tactics, it only means it makes the explanation more clear, doesn't require very complex

equations and there is no need to take the assumptions while taking the reflection and

refraction through the spherical surface on account.

If you have more doubts you can ask on what I have said till now.

And if you aren't convinced to what I have said, then Please give your precious comments

and explanation for the question asked above. Please don't get offended, am not

challenging you just asking you to give your views may be they help in clearing the doubt in

more nice manner and you can toh ask any of your senior regarding this [1][1]

see in the case of flat mirror if you use horizontal axis for measuring the angle, it wont make any difference, you'll get the same results.

But it will definitely make the differences in the case of spherical mirrors.

Now, scientist might have wanted to use the same way of measuring the angles in all kinds of

mirrors, lenses etc etc, so they considered normals as ideal and they used it everywhere to

explain all the phenomenons.

I think so.. (May be again)