The 8 types of electromagnetic waves and their characteristics

The electromagnetic waves , Within physics, play a preponderant role in understanding how the universe works. When discovered by James Maxwell, this opened the window to better understand the workings of light and the unification of electricity, magnetism and optics under the same field.

Unlike mechanical waves that disturb a physical medium, electromagnetic can travel through the vacuum at the speed of light. In addition to the common properties (amplitude, length and frequency), they are composed of two types of perpendicular fields (electric and magnetic) that when oscillating are manifested as vibrations and absorbable absorbable energy.

Types of electromagnetic waves

These undulations are similar to each other and the way of distinguishing them is related to their wavelength and frequency. These properties determine their radiation, visibility, penetration power, heat and other aspects.

To understand them better, they have been grouped into what we know as the electromagnetic spectrum, which reveals their operation associated with the physical world.

Types of electromagnetic waves or electromagnetic spectrum

This classification, which is based on wavelength and frequency, establishes the electromagnetic radiation present in the known universe. This range has two non-visible ends divided by a small visible strip.

In this sense, the frequencies with lower energy are located to the right, while the frequencies with higher frequency are located on the opposite side.

Although not precisely delimited, since some frequencies may overlap, it serves as a general reference. To know these electromagnetic waves in more detail, let us see their location and most important characteristics:

Radio waves

Located at the longest wavelength and lowest frequency range, they range from a few to a billion Hertz. They are the ones that are used to transmit a signal with information of diverse nature and are captured by the antennas. Television, radio, mobiles, planets, stars and other celestial bodies emit them and can be captured.

The microwaves

Located on ultra high (UHF), super high (SHF) and extremely high (EHF) frequencies, they range from 1 GHz to 300 GHz. Unlike previous ones that can measure up to one mile (1.6 km), microwaves They range from a few centimeters to 33 cm.

Given their position in the spectrum, between 100,000 and 400,000 nm, they are used to transmit data on frequencies that are not interfered by radio waves. For this reason, they are applied in radar technology, cell phones, kitchen ovens and computer solutions.

Its oscillation is product of a device known as magnetron, which is a kind of resonant cavity that has 2 disc magnets at the ends. The electromagnetic field is generated by the acceleration of the electrons of the cathode.

Infrared rays

These heat waves are emitted by thermal bodies, some types of lasers and diodes that emit light. Although they often overlap with radio waves and microwaves, their range is between 0.7 and 100 micrometers.

Entities most often produce heat that can be detected by night vision and skin. They are often used for remote controls and special communication systems.

Visible light

In the referential division of the spectrum we find the perceptible light, which has a wavelength between 0.4 and 0.8 micrometers. What we distinguish are the colors of the rainbow, where the lowest frequency is characterized by the red color and the highest by the violet.

Its length values ​​are measured in nanometers and Angstrom represents a very small part of the whole spectrum and this range includes the highest amount of radiation emitted by the sun and stars. In addition, it is the product of the acceleration of electrons in the energy transits.

Our perception of things is based on visible radiation that hits an object and then on the eyes. Then the brain interprets the frequencies that give rise to the color and details present in things.

Ultraviolet rays

These undulations are in the range of 4 and 400 nm, are generated by the sun and other processes emitting large amounts of heat. Prolonged exposure to these shortwaves can cause burns and certain cancers in living things.

Since they are the product of electron jumps in molecules and excited atoms, their energy intervenes in chemical reactions and are used in medicine to sterilize. They are responsible for the ionosphere as the ozone layer avoids its harmful effects on the earth.

X-rays

This designation is because they are invisible electromagnetic waves able to cross opaque bodies and produce photographic impressions. Located between 10 and 0.01 nm (30 to 30,000 PHz), they are the result of electrons jumping from orbits into heavy atoms.

These rays can be emitted by the crown of the sun, pulsars, supernovae and black holes because of their large amount of energy. Their prolonged exposure causes cancer and are used in the medical field to obtain images of bony structures.

Gamma rays

Located at the left end of the spectrum, they are the most frequently occurring waves, usually occurring in black holes, supernovae, pulsars, and neutron stars. They can also be a consequence of fission, nuclear explosions and lightning.

Since they are generated by stabilization processes in the atomic nucleus after radioactive emissions, they are lethal. Their wavelength is subatomic, allowing them to traverse atoms. Even so, they are absorbed by the earth's atmosphere.

Doppler effect

Named after the Austrian physicist Christian Andreas Doppler, it refers to the frequency change in a wave product of the apparent movement of the source in relation to the observer. When analyzing the light of a star, a redshift or a shift to blue is distinguished.

Within the visible spectrum, when the object itself tends to move away, the light emanating shifts to longer wavelengths, represented by the red end. As the object approaches, its wavelength is reduced, representing a shift towards the blue end.

References

  1. Wikipedia (2017). Electromagnetic spectrum. Retrieved from wikipedia.org.
  2. Khan Academy (2016). Light: electromagnetic waves, electromagnetic spectrum and photons. Retrieved from khanacademy.org.
  3. Aesop Project (2016). Radioelectric spectrum. Faculty of Engineering, University of the Republic of Uruguay. Recovered from edu.uy.
  4. Céspedes A., Gabriel (2012). Electromagnetic waves. University of Santiago, Chile. Recovered from slideshare.net.


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