An infinitesimal is a mathematical concept that refers to a quantity that is infinitely small, but not zero. It is often denoted by the symbol "dx" and is used in calculus to represent an infinitely small change in a variable.
Snell's law, also known as the law of refraction, is a principle in physics that describes how light bends when it passes through different mediums. It is related to infinitesimals because it uses the concept of infinitesimally small changes in the angle and velocity of light as it passes through different mediums.
Snell's law is named after Dutch mathematician and astronomer Willebrord Snellius, also known as Snell van Royen. He first described the law in his book "Eratosthenes Batavus" in 1621. However, it is believed that the law was known by ancient Greek mathematicians, such as Ptolemy, before Snell's time.
Yes, Snell's law is a fundamental principle of optics and can be used to predict the path of light in all situations, as long as the materials involved are transparent and the light is not scattered or absorbed. It is widely used in the design of lenses and other optical devices.
Snell's law has many practical applications in everyday life. It is used in the design of eyeglasses, cameras, microscopes, and other optical instruments. It also explains why objects appear distorted when viewed through curved surfaces, such as water or glass, and why a straw appears bent when placed in a glass of water. It is also used in the study of atmospheric refraction and the behavior of light in fiber optics.