# Physics Sample Essay Paper on An Introduction to Weather, Climate, and the Environment

Discussions

Question 3

In lens, chromatic aberration is an optical problem that arises when a lens is unable to bring all the color wavelengths of a white light to a specific focal plane. In other words, it is a focus issue that arises due to differences in the wavelengths of different colors of white light (Devraj 63). With our naked eyes, we cannot detect these differences in wavelengths, but the lenses can detect them. This means that chromatic aberration occurs because different colors have different wavelengths. Accordingly, when a lens is unable to bring all wavelengths of a white light to a particular focal plane, we detect the effect.

A single lens cannot correct this problem, but two lenses of the same material can correct the problem by cancelling the effect of each other. This can be proved mathematically and applied in real life. When chromatic aberration is corrected this way, we end up with achromatic systems (Naval Education 23).

The chromatic aberration problem can occur with lenses in microscopes, cameras as well as in other optic appliances such as binoculars. When it occurs, objects appear blurred and there tends to be streaks of color on the images. The two most common types of chromatic aberration are the lateral and longitudinal. The lateral chromatic aberration concerns itself with image magnification while longitudinal chromatic aberration concerns itself with the formation of images at different positions along the principal axis (Devraj 64). In most cases, lateral chromatic aberration causes the edges of objects to be fringed with color. On the other hand, longitudinal chromatic aberration makes it difficult to keep objects in focus and track them when using devices with faulty lenses. As a result, it is usually advisable to correct chromatic aberration when manufacturing products with lenses.

Question 4

The sky is blue because the air molecules scatter the shorter wavelengths of perceptible light selectively. Nonetheless, we have white clouds because the cloud droplets are by far larger than the air molecules that scatter the sunlight selectively. Accordingly, the cloud droplets do not scatter the white light from the sun as the air molecules do. Instead, the cloud droplets scatter the sunlight in almost the same way regardless of their differences in wavelengths, and in so doing, we end up with white clouds (Ahrens 49).

At sunset, the sky appears red because during that time of the day, the white light that comes from the sun passes through a thick atmosphere before it reaches our eyes. As this takes place, the air molecules and other particles in the air scatter the white light from the sun and manage to remove the shorter waves in the light. In so doing, the white light from the sun reaches our eyes as red because red together with other colors such as orange and yellow have longer wavelengths as compared to blue (Ahrens 49). This explains why the sky appears reddish mostly at sunset rather than appearing bluish.

Finally, the green flash seen in some sunsets in Hawaii is an atmospheric refractive phenomenon that takes place as the sun bends momentarily and turns green. From another perspective, it is a refraction aspect on the earth’s surface as the sun goes down where the earth surface acts as a weak prism that separates the different colors of the sunlight. The phenomenon usually takes very fast such that majority of the people do not notice it thereby it is referred to as a flash (Carroll and Carroll 354).

Works cited

Ahrens, Donald. Meteorology Today: An Introduction to Weather, Climate, and the Environment. S.L.: Brooks/Cole, 2013. Print.

Carroll, Rick, and Carroll Marcie. Hawaii: True Stories of Life on the Island. San Francisco, Calif: Travelers’ Tales, 1999. Print.

Devraj, Singh. Fundamental of optics. New Delhi: PHI Learning PVT limited. 2010. Print.

Naval Education. Basic Optics and Optical Instruments: Revised Edition. Dover Publications, 2013. Print.