# Reflecting light

is it possible to have a surface designed in such a way that ,when it is struck by a ray of light , the reflected light (fort he sake of example) takes a horizontal direction.
My idea is that the light would propagate in a plane which would be more or less parallel to the plane of the surface that the light had struck..
I am not asking whether it is possible to direct the beam in a parallel direction to any given surface bit if it can be done to the actual surface it has impacted .

If it had struck a tile the roof of a house ,for example, could the slate be so designed (or painted) as to reflect the light in the direction of the adjoining slates instead of the angle of incidence that I learned about in school?

I realise that this sounds impossible but ,with so much changing in physics over the years I wonder if this could actually be done.

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thanks for that.
(I do wonder if my level of ignorance in this area has reached its own particular critical threshold!)
Upon inspecting your link I can now see that what I was looking for is easily possible .
Is it possible to also arrange the surface so that a ray of light arriving at the critical angle might propagate not only tangentially to the surface but also a bit like you might see if you cast a pebble in the water -ie if you were throwing a dart at a dart board (as an analogy to the ray of light ) could the dart be thrown at the bull's eye (at the critical angle of course) and then be deflected to any (or all) of the numbers ? or ,ideally just to the area between due South and due East (or any particular area you happened to want)
I imagine a rabbit's warren of optical fibres might do the trick but would that be overkill ?
Can it be done at all simply?
Would the surface need to be tracking the sun all the while?

Where's my post?

geordief seems to have read it but where is it now?

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