Total Internal Reflection a doubt?

[archijun3]

I was reading about a case of total internal reflection in mirrors and something got me curious...
Is there anything such as 'weak refractions'??
In the diagram of the mirror I saw, as a ray of light from an object entered a mirror, it was reflected by the silver coating, and then by the surface of the mirror (assuming it's because of total internal reflection). This process was repeated three times more, and the light ray emerged out of the mirror.
The doubt I have here is, everytime the ray of light was reflected off from the surface of the mirror (total internal reflection), there was a ray of light exiting the mirror at that point. Where exactly did that ray of light come from?

Plus, if I may ask further, how many times will total internal reflection have taken place in the above situation?

 

[CWatters]

I believe the example you are looking at is demonstrating "partial internal reflections" not "total internal reflections".

See the diagram below (from.. http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/totint.html).

On the left the angle of incidence is such that the light is partly relected and partly refracted.

As the angle changes there is a point at which the light that emerges is refracted along the surface. This is called the critical angle.

On the right the angle is such that the light is totaly reflected and no light emerges.

 

[CWatters]

Plus, if I may ask further, how many times will total internal reflection have taken place in the above situation?

I make the sequence..

A refraction
A reflection off the silvered surface
A partial internal reflection (some light emerges)

This is then repeated three more times..

A reflection off the silvered surface
A partial internal reflection (some light emerges)
A reflection off the silvered surface
A partial internal reflection (some light emerges)
A reflection off the silvered surface
A partial internal reflection (some light emerges)

Because the very last reflection is partial there will be a faint emerging ray which is the one you describe as leaving the mirror.

In the real world you would probably get a lot more internal reflections because mirrors have parallel surfaces. That means once the ray is bouncing around between the surfaces the angle of incidence doesn't change much so there is nothing but the edge of the mirror to stop internal reflections. That's more or less how crude fiber optic cables work.

 

[archijun3]

My thanks to CWatters :)
So this is an example of partial internal reflection isn't it??
I was confused because the heading was written as total internal reflection..zz
It's been a great help xD Thank you!

 

[sardar]

Thank you for bringing up this interesting question about total internal reflection and weak refractions. To answer your first question, yes, there is such a thing as weak refractions. This refers to the phenomenon where some of the light passing through a medium is refracted, while the majority of the light is reflected. This is commonly seen in materials with high refractive indices, such as glass or water.

In the case of total internal reflection, it is important to understand that the light ray is not actually exiting the mirror at each point of reflection. Instead, the ray is being bounced back and forth between the two surfaces of the mirror, with each reflection causing a small amount of light to be transmitted through the glass. This is why you see a ray of light exiting the mirror at each reflection point.

As for your second question, the number of times total internal reflection takes place in a given situation depends on the angle at which the light enters the mirror and the refractive index of the medium. In general, the light will continue to reflect until it reaches an angle of incidence that is greater than the critical angle, at which point it will be refracted out of the medium.

I hope this helps to clarify your doubts about total internal reflection. It is a fascinating phenomenon that has many practical applications, such as in fiber optics and prism-based devices. If you have any further questions, please don't hesitate to ask. As scientists, it is important to constantly question and seek understanding of the world around us.