What is the Speed of Electromagnetic Waves in a Vacuum?
Electromagnetic radiation is a form of energy many industries use, especially the food processing industry, to kill microorganisms in food. Electromagnetic radiation is beneficial as its application is numerous. Electromagnetic waves are speedy and can travel far distances in less than a second. The speed at which electromagnetic radiation travels in a vacuum is even faster. While you may have thought that the speed of electromagnetic waves is dependent on the source of radiation, it is not so. In this article, you’d get to understand more about electromagnetic waves and their speed in a vacuum. We’d also talk about the properties and types of electromagnetic waves. Without further ado, let’s get right into it.
What are Electromagnetic Waves?
An electromagnetic wave is a type of wave consisting of oscillating electric and magnetic fields that are perpendicular to each other. Electromagnetic waves can travel in a vacuum carrying electromagnetic energy. Additionally, because electromagnetic waves consist of electric and magnetic waves, they don’t get deflected by electrical or magnetic waves; this makes them capable of traveling through anything. Nevertheless, electromagnetic waves are capable of showing diffraction and interference. Unlike mechanical waves, electromagnetic waves do not require the presence of a material medium to transport their energy from one location to another; this is one of the main features of electromagnetic waves that makes them so valuable. For example, sound waves are an example of mechanical waves, while light waves are an example of electromagnetic waves.
Physical Properties of Electromagnetic Waves:
To help you understand how electromagnetic waves work, we will be talking about three properties of electromagnetic waves. While you already know, all electromagnetic waves are transverse waves and can travel in a vacuum. However, we can describe electromagnetic waves with the following three physical properties:
● Frequency
The frequency of electromagnetic waves is a term that describes the number of waves produced every second. The unit for measuring frequency is Hertz (Hz). Similarly, the period is a term that describes the time it takes to complete one wave or cycle. The relationship between period and frequency is that period is the reciprocal of the frequency.
● Wavelength
The wavelength of an electromagnetic wave is the distance from one crest or trough to the other in a wave. The trough is the lowest point in a wave, whereas the crest is the highest point on the wave. Since wavelength is distance, its unit can be in meters, centimeters, millimeters, or nanometers.
● Intensity
The intensity of an electromagnetic wave is the power of a magnetic or electrical field per unit area. The area is measured on the plane perpendicular to the direction of the propagation of the energy. The unit of intensity could be anything from watt per square meter, kilogram per cubic meter, and so on.
Types of Electromagnetic Waves:
We can classify electromagnetic waves into the following seven waves. Note that while there are different types of electromagnetic waves in the spectrum, there are no precise boundaries; instead, they fade into each other like the bands of rainbows.
● Gamma rays
Gamma rays are a type of electromagnetic wave with the most energetic photons, with no defined lower wavelength limit. Scientists use gamma rays experimentally because of their penetrating ability. Scientists also use gamma rays for the irradiation of food and medicine for sterilization.
● X-rays
X-rays are a type of electromagnetic wave that generates high energy thus can interact with matter through the Compton Effect. We can subdivide X-rays into hard X-rays and soft X-rays. Hard X-rays have shorter wavelengths than soft X-rays and can pass through many substances with little absorption; this is why a typical application of X-rays is to see through objects.
● Ultraviolet
In the electromagnetic spectrum, ultraviolet waves have the most extended wavelength radiation whose photons are energetic enough to ionize atoms, separate the electrons from them, and then cause chemical reactions. Ultraviolet waves can also cause several objects to glow when exposed to visible light; this is known as fluorescence.
● Visible light
Above infrared in the electromagnetic spectrum is visible light. Visible radiation is the part of the electromagnetic spectrum that the human eyes are most sensitive to. Objects can absorb and reflect visible light. Hence, the human eyes process several reflections of frequencies into different shades of hues. Thus visible light helps us identify colors.
● Infrared
Infrared waves are electromagnetic radiation, a continuum of frequencies produced when atoms absorb and then release energy. We can divide the infrared part of the electromagnetic spectrum into three main ranges: far, mid, and near-infrared. We can use infrared waves as heat sensors, thermal imaging, and night vision equipment.
● Microwave
Microwaves are like radio waves, but they have a shorter wavelength. We can generate microwave energy by magnetron and klystron tubes and solid-state diodes. Short antennas can absorb and emit microwaves and polar molecules coupling with rotational and vibrational modes resulting in bulk heating.
● Radio wave
Radio waves are a type of electromagnetic wave used in transmitting information like in radio broadcasting, mobile phones, television, and wireless networks over a long distance. Antennas can generate and receive radio waves. In the generation of radio waves, a transmitter generates an AC while the antenna generates an oscillating magnetic and electric field that radiates away from the antenna.
Speed of Electromagnetic Waves:
In a vacuum, electromagnetic waves travel at the speed of light. In a vacuum, electromagnetic waves transport their energy at a speed of 3.00 x 108 m/s. There is no reduction of the speed of electromagnetic waves in a vacuum because there is no absorption and reemission of wave energy by the atoms of the material. But when electromagnetic waves travel through a material medium, the speed reduces depending on the density of the medium; this means that the net speed of electromagnetic waves will be less than 3.00 x 108 m/s when propagating its energy through a material medium.
Bottom Line:
In conclusion, when asked, what is the speed of electromagnetic waves in a vacuum, what will you say? We hope that this article clarifies that the medium at which electromagnetic waves are traveling has a significant impact on the speed of the wave. If you have any more questions about the speed of electromagnetic waves, feel free to leave a comment in the comment section below.
