The term "apparent deep" most likely refers to "apparent depth," which is an optical phenomenon. Apparent depth is the perceived depth of an object submerged in a medium, such as water, which looks different from the real or actual depth due to the refraction of light. In essence:
- Real depth is the true, physical distance from the surface of the medium to the object.
- Apparent depth is the depth at which the object appears to be when viewed from above, which is usually less than the real depth.
This difference occurs because light bends (refracts) as it passes from one medium (like water) to another (like air), making submerged objects appear closer to the surface than they actually are. This optical illusion explains everyday observations like why a swimming pool looks shallower than it really is or why a stick partially submerged in water appears bent. The relationship between real depth (D), apparent depth (d), and the refractive index (n) of the medium is given by:
Apparent depth=Real depthRefractive index\text{Apparent depth}=\frac{\text{Real depth}}{\text{Refractive index}}Apparent depth=Refractive indexReal depth​
Hence, apparent depth depends on the medium's refractive index and the observer's viewpoint. Understanding this concept is important in optics and helps explain how light behaves when traveling through different materials.
