By David Nashed
We’ve all heard of electromagnetic radiation. We’ve also all heard of how it’s emitted from our phones and TVs, and how harmful it is to us. But, is that really the case? In this article, we’ll be discussing what constitutes electromagnetic radiation, how it is formed, and how it can affect humans.
Electromagnetic (EM) radiation is, in layman's terms, a form of energy. It can come from a variety of sources and take a variety of shapes, such as radio waves, X-rays, and gamma rays. What makes it unique, however, is the fact that it is a product of electricity and magnetism.
The way EM radiation is formed is rather interesting. As we all know, electricity relies on the flow of electrons to produce energy. These flowing electrons produce electricity fields, which can exert a force on nearby charged particles. And so when there are multiple electrons flowing nearby each other, their electricity fields accelerate each other.
When multiple electrons are accelerating each other, they produce a magnetic force; which is also known as a magnetic field.
This newly formed magnetic field is perpendicular to the previously formed electric field. Additionally, they are both constantly oscillating. As a result of these two oscillating fields, a bundle of light is created. This bundle of light is also known as a photon, and it is what composes EM radiation.
Photons travel in waves at the fastest speed possible in the universe: 186,282 miles per second in a vacuum. This is also known as the speed of light.
However, not all photon waves are the same! They have different characteristics such as wavelength and frequency. Wavelength describes the distance between the two consecutive peaks of a wave. Frequency is the number of wavelengths before a given point.
Furthermore, waves with a high wavelength will have a low frequency. Similarly, waves with a low wavelength will have a high frequency. This is because for there to be a high frequency, there must be multiple wavelengths, and for there to be multiple wavelengths, they must be short in length.
The way we measure EM radiation is with something called the electromagnetic spectrum. The electromagnetic spectrum contains a vast number of waves, each with their own frequency and wavelength. In general, there are seven regions of the electromagnetic spectrum.
The common designations are (from left to right): radio waves, microwaves, infrared (IR), visible, ultraviolet (UV), X-rays, and gamma rays. As you go from left to right, the wavelengths decrease and the frequency increases. The longer the wavelength, the more energy the ray has. Based on this statement, we know that gamma rays and X-rays are the strongest rays in the electromagnetic spectrum.
Now, it’s time to answer the question that so many have asked: can electromagnetic radiation harm humans? Well, the answer is a bit complicated. Let’s start with the two weakest rays, microwaves and radio waves.
These types of electromagnetic radiation are often called non-ionizing radiation, which means that they don’t have the ability to ionize an atom; they cannot remove an electron, and therefore cannot do any permanent damage to one’s cells.
Computers and phones both emit non-ionizing radiation, which means that they too are not harmful. With this being said, it’s important that we spend time away from our computers. Prolonged periods spent sitting and staring at a computer screen can harm one’s blood circulation, as well as cause other health complications.
Next up, let’s talk about visible light and infrared light. Similar to microwaves and radio waves, visible light and infrared light are also non-ionizing radiation, which means that they cannot do any permanent damage to one’s cells.
Now, the next type of rays we’ll be talking about are UV rays. UV rays can do serious damage to human tissue. According to the Skin Cancer Foundation, prolonged unprotected exposure to UV rays can result in genetic defects, mutations, and skin cancer.
Even worse, the sun actually emits UV rays! However, there’s no need to actually worry. One would have to be exposed to UV rays for an incredible amount of time for there to be any lasting side effects. Additionally, it’s easy to block out UV rays with the usage of sunblock, as the frequency of UV rays is not high enough to penetrate the sunblock’s seal.
The next two, and final, types of rays are gamma rays and X-rays. X-rays are divided into two categories: soft X-rays and hard X-rays. Soft X-rays occupy the region in the electromagnetic spectrum between UV and gamma rays. Hard X-rays occupy the same region as gamma rays. Soft X-rays are slightly weaker than hard X-rays, but are still extremely dangerous. Soft X-rays can cause severe damage if one is repeatedly exposed to them while unprotected. However, we are rarely exposed to them during our day-to-day basis.
Gamma rays and hard-X-rays are nearly identical when it comes to frequency. The only difference between them is how they’re produced. X-rays are produced by accelerating electrons, while gamma rays are produced by atomic nuclei. These types of rays are incredibly powerful and are extremely dangerous to humans. If one is exposed to them while not wearing the proper protective equipment, he or she may experience permanent cell damage/mutations.
So, let’s summarize what we discussed in this article. First off, electromagnetic waves are composed of photons, which are essentially bundles of light that are created by electric fields and magnetic fields oscillating beside each other at a 90 degree angle.
Second, electromagnetic waves can be categorized on the electromagnetic spectrum. There are seven general types of electromagnetic waves, each with their own unique frequency and wavelength. These waves are radio waves, microwaves, infrared, visible waves, ultraviolet, X-ray, and gamma.
Radio waves, microwaves, infrared, and visible waves are all practically harmless. Ultraviolet rays can be harmful to humans; though this can be easily prevented by avoiding prolonged exposure and wearing sunscreen.
X-rays, and gamma rays can cause permanent damage to humans. Anyone working in close proximity to either of these types of electromagnetic radiation should keep their distance and wear proper personal protective equipment.
I hope that you enjoyed this article, and that it helped you understand electromagnetic radiation a bit better!
Credit: AdvancedPhotonSource © 2011 AdvancedPhotonSource
Q: What exactly is a photon?
A: Photons are the basic unit of all forms of light. They are stable, have neither charge nor mass, and are constantly in movement. They are also the smallest possible quantity of electromagnetic radiation possible. Their primary use is to transmit light.
Q: Can we see electromagnetic waves?
A: Most electromagnetic waves are completely invisible, with the exception being visible light. Visible light falls under the spectrum of colours such as red, orange, yellow, green, blue, indigo, and violet. The reason we can’t see the other types of electromagnetic waves is that their wavelengths are either too large—radio waves and microwaves—or too small— X-rays and gamma rays. The wavelength of visible light on the other hand, is just large enough for us to view.