In my latest post I introduced a variety of qualities of waves as well as the different types of waves that we come into contact with in day to day life. In this post am going to be speaking about electromagnetic radiation as well as the types of electromagnetic radiation that we are exposed to, that we may or may not know about.
We coming to contact with electromagnetic radiation every single day but don’t realise it. In my previous post, we saw that energy can be transmitted from one point to another in a medium by means of transverse or longitudinal waves. Both of these waves involve the disturbance of particles of the medium through which the wave travels. However, there are also other types of radiation whereby energy is transmitted without requiring a medium. This type of radiation is often known as electromagnetic radiation and it is what we are going to be discussing. Radio waves as well as microwaves and visible light and X-rays, are examples of such electromagnetic radiation. All of these waves can be transmitted through an empty space, which basically means that they do not require a medium in order to travel from one point to another.
Source and Nature of Electromagnetic Radiation
EM radiation originates as a result of the acceleration of electric charges. Take for example electrons and the changing magnetic and electric Fields created by them. A magnetic field is produced around a moving electric charge.
Types of Electromagnetic Radiation
Radio waves
Radio waves are found to have the longest wavelength than all other objects that give off electromagnetic radiation in the spectrum. Natural radio waves come from lightning and the Galaxies among others. Radio waves are also developed by humans for radio communication and navigation systems.
Radio waves are divided according to the wavelengths such is the long wave, the medium wave and the short wave.
Microwaves
Microwaves have wavelengths between those of radio waves and infrared waves. They are used for cooking purposes as well as satellite communication and radar speed traps. There are many other uses for microwaves but I have only stated 3.
Infrared rays
Infrared rays are adjacent to the red light side of the visible spectrum with a wavelength longer than those of red light. Infrared rays with a wavelength closer to the microwave range of the electromagnetic Spectrum are radiated from hot objects.
Visible spectrum
Visible light forms from a very small part of the electromagnetic Spectrum, and has wavelengths of approximately 390nm to approximately 750nm.
The human eye is capable of seeing the seven rainbow colours that white light consists of, hence the term visible spectrum. Visible light enables us to see colours and objects. It forms the basis of life on earth because it is used by green plants to produce food substances and provide oxygen through photosynthesis.
Ultraviolet rays
Ultraviolet rays border on the violet part of the visible spectrum with a wavelength shorter than those of violet light. Ultraviolet light comes from the sun and fluorescent lights and is invisible to the eye.
X-rays
X-rays have a high frequency and thus radiation with a high energy. X-Rays can therefore penetrate human skin and flesh but not bones and teeth. They are widely used to take photos or images on a photographic film these are also known as X-ray photos, for medical diagnosis. They’re also used by doctors for Cat scans.
Gamma rays
Gamma rays have the highest frequency and are therefore the highest energy in the electromagnetic spectrum. They are released through Radioactive elements. Gamma rays can be very harmful and dangerous but can also be used in a good way. They are used to destroy cancer cells during radiotherapy and are used for killing bacteria and sterilizing food or medical instruments.
Dangers of Radiation
The greater the penetrating ability of the electromagnetic rays, the more damage they can do to the molecules in our cells. excessive exposure to UV rays can cause ageing and skin damage, as well as cancer.
Fun fact:
The skin becomes Brown or Darker when exposed to moderate levels of UV rays ( the brown pigment melanin is released). It helps to prevent damage to the deeper layers of the tissue. Suntan lotions contain compounds that help us to protect the skin from these sort of rays.
Radiation from Cellphones
Cell phones use microwaves with relatively low frequencies and therefore have a reasonably low penetrating ability. Nevertheless, there are major concerns that the excessive use of cellphones World-Wide may pose a health risk. The danger exists that a part of the energy may penetrate your head because cell phones are held against your ear.
Continuous research is being done about the relationship between the use of cellphones and the incidence of cancer. So far It cannot be proven with certainty, that cell phone usage causes cancer. However, it is strongly recommended that the use of cellphones is limited, especially indoors or to the use of hands-free systems
THE END
References
1.https://en.wikipedia.org/wiki/Electromagnetic_radiation
2.https://en.wikipedia.org/wiki/Infrared
3.https://en.wikipedia.org/wiki/Visible_spectrum
4.https://en.wikipedia.org/wiki/Ultraviolet
5.https://en.wikipedia.org/wiki/X-ray
6.https://en.wikipedia.org/wiki/Gamma_ray
7.https://en.wikipedia.org/wiki/Electromagnetic_radiation_and_health
