Apparent Depth in Different Medium
As we know, the phenomenon of apparent depth occurs due to the bending of light (refraction) while travelling from one medium to another. When dealing with mediums, we define two types of them: denser medium and rarer medium, which are relative terms. A medium with a higher refractive index is denser compared to a medium with a lower refractive index, while the same medium can be considered rarer when compared to another medium with a higher refractive index.
When light rays pass from a denser to a rarer medium, they get refracted away from the normal (the common normal to both mediums), causing the light rays to appear to be coming from a virtual object formed above the actual object. If the light rays pass from a rarer to a denser medium, they move towards the normal, causing the light rays to appear to be coming from a virtual object formed below the actual object. This is how apparent depth changes according to denser and rarer mediums.
Laws of Refraction and Apparent Depth
Apparent depth can be explained using the laws of refraction, specifically Snell’s Law. According to Snell’s Law, the angle of incidence and the angle of refraction are related to the refractive indices of the two media:
μ1 . sin(θ2) = μ2 . sin(θ1)
Where,
- μ1 and μ2 are the refractive indices of the two media,
- θ1 is the angle of incidence in the first medium, and
- θ2 is the angle of incidence in the first medium.
Refere illustration for further understanding.
Apparent Depth
Apparent Depth is an example of reflection of light from different mediums and can be observed in many areas. Such as when we drink water from a bottle or any vessel we have an illusion that the bottle’s base is very near to us, but after it gets empty we realize its actual depth. This illusion is a result of the phenomenon known as Apparent Depth. Apparent Depth plays a crucial role in our perception of objects submerged in liquids as there are many such examples like a fish in a pond appearing near to the surface, the bottom of the Swimming Pool appearing near to the surface, and many more.
In this article, we will dive deep into the phenomenon of apparent depth, exploring its definition, the laws of refraction governing it, its mathematical formulation, the factors affecting it, and solving a problem to solidify our understanding.
Table of Content
- What is Apparent Depth?
- Apparent Depth in Different Medium
- Apparent Depth Formula
- Apparent and Real Depth
- Factors Affecting Apparent Depth