Electromagnetic Radiation Essay

Introduction:

Key Concepts:

Light as a form of electromagnetic radiation:

Light can be classified as a form of electromagnetic radiation, which includes visible light. The ‘light’ commonly referred to in everyday life belongs in this category. The electromagnetic spectrum includes other types of radiation such as gamma rays, radio waves and cosmic rays, all of which possess distinct wavelengths, frequencies and energy levels. These forms of electromagnetic radiation are not visible to the human eye but can be perceived by selected species of animals, such as bees. Figure 1 below displays the electromagnetic spectrum and provides a basic insight into the respective characteristics of different forms of radiation.

Figure 1: The Electromagnetic Spectrum

Light is a series of self-propagating transverse waves composed of electric and magnetic fields in a fixed ratio. The distance between the crests of successive waves is known as the wavelength, denoted by the symbol λ (lambda), as shown in Figure 2. The frequency of a wave is defined as the number of waves passing through a given point per second.

Figure 2

The velocity of a wave is given by the formula:

v=fλ

Where v = velocity (ms-1) f = frequency (Hertz) λ = wavelength (m)

or if the wave is travelling through a vacuum:

c=fλ where c = speed of light (ms-1) f = frequency (Hertz) λ = wavelength (m)

Law of Reflection:

When a ray of light is bounced or reflected off of a plane surface, there is a specific law that can be used to predict the angle at which it is reflected off of the surface. This is known as the ‘Law of Reflection’ and it states:

“… the incident ray, the reflected ray, and th...

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...development.

Within the various applications of optics investigated, it is clear that while technology has progressed and advanced over time, optical devices such as mirrors, prisms and lenses will still be very much in use in the future. The fundamental properties of these instruments are utilised and manipulated in a range of optical gadgets such as telescopes and projectors. Even in areas outside of visual aid and entertainment, optical apparatuses can be used to trick the eye and even showcase 3D images, as seen in holograms. Although metamaterials used in stealth technology lack obvious uses of mirrors, prisms and lenses, knowledge of principles observed in these tools such as reflection and refraction is used in the developing stages. In can then be said that the technology is based on understanding of the three aforementioned devices.