The Sun appears white at noon primarily because of the Earth’s atmosphere. The Sun emits light across the entire spectrum, including all the colors of the rainbow. This is known as white light. However, when sunlight passes through the Earth’s atmosphere, it is scattered in different directions by the gases and particles in the atmosphere.

The Earth’s atmosphere is composed of various gases, such as nitrogen and oxygen, as well as tiny particles like water droplets and dust. This scattering of sunlight is more effective for shorter wavelengths of light (blue and violet) compared to longer wavelengths (red and yellow). As a result, the shorter wavelengths of light are scattered more than the longer wavelengths when sunlight enters the Earth’s atmosphere.

During the daytime, when the Sun is high in the sky, the sunlight has to pass through a relatively smaller portion of the Earth’s atmosphere. This means that the shorter wavelengths are scattered to a greater extent, and the blue and violet light is dispersed in different directions. The remaining sunlight that reaches our eyes is more skewed toward the longer wavelengths, which are predominantly red, orange, and yellow.

Therefore, when you look at the Sun directly at noon, it may appear more yellow or even slightly orange due to the preferential scattering of shorter wavelengths. However, the overall combination of these scattered colors often makes the Sun appear white to our eyes.
It’s important to note that looking directly at the Sun, especially at noon when it is most intense, can be harmful to your eyes. Always use proper solar viewing equipment to observe the Sun safely.

a) Noopur is suffering from myopia, also known as nearsightedness. In myopia, distant objects appear blurry, while close objects can be seen more clearly.
b) For myopia correction, a concave lens is needed. The power of the lens is given as -4.5D. The negative sign indicates that it is a concave lens. The focal length (f) of the lens can be calculated using the formula:
f= (-1)/4.5= -0.22 cm,as concave lens.

c) Defective Eye (Myopia):
Parallel rays from a distant object converge in front of the retina, causing a blurry image.The image formed is in front of the retina.
Correction with Concave Lens: Parallel rays are diverged by the concave lens.
The diverged rays appear to come from a virtual focus point, resulting in the formation of a clear image on the retina.
Please note that drawing accurate ray diagrams requires specific measurements and angles, but a basic representation can be made to illustrate the concept.

d) Causes of Myopia:
Eyeball Shape: Myopia is often associated with an elongated eyeball, where the distance from the cornea to the retina is too long. And secondly, Due to excess curvature of eye lens.
Genetics: Family history plays a significant role, and individuals with myopic parents are more likely to develop myopia.
Environmental Factors: Excessive near work, such as reading or using digital devices for extended periods, can contribute to the development and progression of myopia.
It’s important for Noopur to consult an eye care professional for a comprehensive eye examination to determine the exact prescription and appropriate corrective measures. Regular eye check-ups are recommended for the timely detection and management of vision-related issues.