A wave is defined as a disturbance that propagates through a medium from one point to another. In physics, there are many different forms of waves. Despite the fact that they have a lot in common, they have particular behaviours and characteristics that set them apart.

What are electromagnetic waves?

Waves in physics are classified into three kinds based on the particle of motion and energy direction: Electromagnetic waves, Mechanical waves, and Matter waves. 

Electromagnetic Waves

Electromagnetic waves are made up of disturbances that can travel through space without the use of a medium. Light, for example, is an example of an electromagnetic wave. The sun’s light travels between the earth and the sun in a vacuum.

Instead of vibrating molecules, electromagnetic waves rely on the electric field to travel. A magnetic field exists in addition to an electric field, and it oscillates in phase with the electric field at 90 degrees.

In the vacuum, all electromagnetic fields propagate at a speed of 3 \times 10^8m s^ {-1}. In a vacuum, this is often referred to as the speed of light. Waves are classified according to the medium in which they propagate and how energy passes through them.

Different Types of Electromagnetic Waves

Electromagnetic waves can have a variety of frequencies, and they are commonly referred to by numerous names due to their various sources and effects on matter. These are radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays, in order of increasing frequency and decreasing wavelength.

Electromagnetic waves are created by electrically charged particles that are accelerating, and the waves can then interact with other charged particles, putting a force on them. Keep in mind that electromagnetic waves can transfer energy, momentum, and angular momentum from their originating particle to the matter with which they interact.

Electromagnetic radiation (EMR) is thus linked with electromagnetic waves that are free to spread (or “radiate”) without the continued effect of the moving charges that generated them, as long as they are sufficiently far from those charges. As a result, EMR is also known as the far-field. In its most basic form, EMR is made up of electromagnetic waves, which are synchronized oscillations of electric and magnetic fields.

The electromagnetic (EM) spectrum encompasses all types of electromagnetic radiation. Radiation is defined as energy that travels and spreads out as it does so; for example, visible light from a bulb in your home and radio waves from a radio station are both examples of electromagnetic radiation.

Microwaves, infrared light, ultraviolet light, X-rays, and gamma-rays are the additional forms of electromagnetic radiation that make up the electromagnetic spectrum. Photons make up all EM waves, which move across space until they collide with matter; some waves are absorbed, while others are reflected. EM waves are classified into seven fundamental categories by scientists, yet they are all representations of the same phenomenon.

1. Radio Waves: Communication 

The lowest-frequency waves in the electromagnetic spectrum are radio waves. Other signals can be transmitted by radio waves to receivers, which then convert the signals into useful data.

Many natural and man-made objects generate radio waves. Anything that produces heat emits radiation across the full spectrum, though in varying degrees. Radio waves are emitted by stars, planets, and other celestial bodies.

Radio and television stations, as well as cellular businesses, all emit radio waves that convey signals to your television, radio, or cellphone antennae.

2. Microwaves: Heating and Data Transmission

Microwaves have shorter wavelengths than radio waves, with centimetre-long wavelengths. Microwaves are used to cook food, transmit data, and in radar to help forecast the weather.

Because microwaves can penetrate clouds, smoke, and light rain, they are beneficial in communication. The universe is replete with cosmic microwave background radiation, which scientists believe contains clues to the Big Bang’s origin.

3. Infrared Waves: Invisible Heat 

Between microwaves and visible light, infrared waves are in the lower-middle range of frequencies in the electromagnetic spectrum. Infrared waves have lengths ranging from a few millimetres to microscopic.

Shorter-wavelength infrared rays do not produce much heat and are utilized in remote controls and imaging technologies. On contrary, longer-wavelength infrared waves produce heat and include radiation emitted by fire, the sun, and other heat-producing sources.

4. Visible Light Rays 

Visible light waves allow you to see the world around you. People perceive the colours of the rainbow as distinct frequencies of visible light. The frequencies progress from shorter wavelengths, which are detected as reds, to longer wavelengths, which are detected as violet colours.

The sun is, of course, the most visible natural source of visible light. Depending on which wavelengths of light an object absorbs and reflects, it is viewed as having distinct colours.

5. Ultraviolet Waves: Energetic Light

After visible light, ultraviolet waves have the shortest wavelength. Sunburns are caused by the Sun’s UV radiation. The ozone layer shields us from the Sun’s UV rays. UV light can be seen by some insects, such as bumblebees. Powerful telescopes, such as the Hubble Space Telescope, use ultraviolet light to see faraway stars.

6. X-rays: Penetrating Radiation

X-rays are extremely high-energy waves with wavelengths ranging from 0.03 to 3 nanometers, which is less than an atom’s length. X-rays are emitted by sources that produce extremely high temperatures, such as the corona of the sun, which is far hotter than the sun’s surface.

X-rays are produced naturally by extremely intense cosmic phenomena such as pulsars, supernovae, and black holes. In imaging technology, X-rays are routinely utilized to visualize bone structures within the body.

7. Gamma Rays: Nuclear Energy

Only the most energetic cosmic objects, such as pulsars, neutron stars, supernovae, and black holes, release gamma waves, which are the highest-frequency EM waves. Lightning, nuclear explosions, and radioactive decay are examples of terrestrial sources.

The wavelengths of gamma waves are measured at the subatomic level and can travel through empty space within an atom. Living cells can be destroyed by gamma rays, however, the Earth’s atmosphere absorbs any gamma rays that reach the planet.