Light refraction is a phenomenon that occurs when light travels from one medium to another, causing it to change speed and direction. This bending of light is crucial for understanding how lenses work and is governed by Snell's Law. Snell's Law states that the product of the index of refraction of the first medium and the sine of the angle of incidence is equal to the product of the index of refraction of the second medium and the sine of the angle of refraction. This relationship can be expressed mathematically as:

$$ n_1 \sin(\theta_1) = n_2 \sin(\theta_2) $$

In this equation, $ n_1 $ and $ n_2 $ are the indices of refraction for the first and second materials, respectively, while $ \theta_1 $ is the angle of incidence (the angle at which light hits the boundary) and $ \theta_2 $ is the angle of refraction (the angle at which light exits into the new medium).

When light enters a medium with a higher index of refraction (like air to water), it bends towards the normal, resulting in an angle of refraction that is smaller than the angle of incidence. For example, if light enters water from air at a 30-degree angle, the angle of refraction can be calculated using Snell's Law. Given that the index of refraction for air is approximately 1 and for water is about 1.33, the calculation yields an angle of refraction of approximately 22.1 degrees.

Conversely, when light exits a medium with a higher index of refraction to one with a lower index (like glass to air), it bends away from the normal. In this case, if light exits glass (with an index of refraction of 1.46) into air at the same 30-degree angle, the angle of refraction is found to be approximately 46.9 degrees, which is greater than the angle of incidence.

Understanding these principles of light refraction and the application of Snell's Law is essential for solving problems related to optics, such as determining how light behaves as it passes through different materials. This knowledge is foundational for fields such as physics, engineering, and various applied sciences.

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