The electromagnetic spectrum ranges from radio waves to gamma rays. We only perceive a tiny fraction: visible light. WiFi, 5G, microwaves, and infrared light are all part of the same spectrum. Understanding its regions helps you grasp what kind of radiation surrounds you every day.

Electromagnetic spectrum: what it is and types of radiation

The electromagnetic spectrum is the complete set of all existing electromagnetic waves, organized according to their frequency and wavelength. From the radio waves that power your mobile phone to the gamma rays used in nuclear medicine, all this radiation is part of the same physical phenomenon: electric and magnetic fields that propagate through space at the speed of light.

What changes between one wave and another is its energy. The higher the frequency (and the shorter the wavelength), the more energy they carry. This difference determines how they interact with matter and, in particular, with our body.

The regions of the electromagnetic spectrum

The electromagnetic spectrum is divided into seven main regions, ordered from lowest to highest frequency:

Radio waves

These have the lowest frequency and longest wavelength. They are used in AM/FM radio stations, television, and long-distance communications. They are non-ionizing radiation with very low energy.

Microwaves

They occupy the range between radio waves and infrared. They are used in microwave ovens, WiFi networks, Bluetooth, 5G technology, and satellite communications. These are the waves that have increased the most in our home environment in recent decades.

Infrared

Infrared radiation is located between microwaves and visible light. Every body with a temperature emits infrared. It is used in remote controls, thermal cameras, and heat therapies. Red and near-infrared light have applications in photobiomodulation, a technique used to stimulate cellular regeneration processes.

Visible light

It is the only portion of the electromagnetic spectrum that the human eye can detect. The visible electromagnetic spectrum covers wavelengths between 380 nm (violet) and 700 nm (red). All the visual information we process comes from this tiny band.

Ultraviolet

UV radiation has more energy than visible light. In moderate doses, it promotes vitamin D synthesis, but excessive exposure causes sunburn and cellular damage. It is the boundary between non-ionizing and ionizing radiation.

X-rays

They penetrate soft tissues and are used in medical diagnosis. They are ionizing radiation: they have enough energy to strip electrons from atoms and damage DNA. That is why their clinical use is limited to what is strictly necessary.

Gamma rays

These have the highest frequency and energy in the spectrum. They are generated in nuclear processes and are used in oncological radiotherapy. Their penetrating power is the highest of the entire electromagnetic spectrum.

Ionizing and non-ionizing radiation: the key difference

The most important dividing line in the spectrum is the one that separates non-ionizing radiation (from radio waves to visible light) from ionizing radiation (high-energy ultraviolet, X-rays, and gamma rays).

Ionizing radiation has enough energy to modify the molecular structure of cells. That is why X-rays and gamma rays are strictly regulated in medicine.

Non-ionizing radiation, such as that emitted by WiFi, mobile phones, or 5G antennas, does not have the energy to break chemical bonds. However, prolonged exposure to high densities of non-ionizing radiation is being studied for its potential biological effects: sleep disturbances, oxidative stress, and alteration of cellular processes.

The electromagnetic spectrum in your day-to-day life

You don't need to be a physicist to interact with the electromagnetic spectrum. You do it every second:

• When you turn on the WiFi, your router emits microwaves in the 2.4 GHz or 5 GHz range.
• When using your mobile, your smartphone communicates via radiofrequency with the nearest antenna.
• When heating food, the microwave oven excites water molecules with 2.45 GHz waves.
• When sunbathing, you receive visible, infrared, and ultraviolet light.
• When looking at an LED screen, your retina absorbs visible light with a high proportion of blue light.

The difference between these last few years and previous decades is density. The number of devices emitting non-ionizing radiation in an average home has multiplied. Understanding what type of radiation each device generates allows you to make more informed decisions about how to manage your exposure.

Frequently asked questions about the electromagnetic spectrum

What is the electromagnetic spectrum in simple terms?

It is the classification of all types of existing electromagnetic radiation, ordered by their energy. From radio waves (low energy) to gamma rays (high energy), including microwaves, infrared, the light you see, ultraviolet, and X-rays.

Are WiFi and 5G dangerous according to the electromagnetic spectrum?

WiFi and 5G emit non-ionizing radiation (microwaves), which does not have the energy to directly damage DNA. However, the WHO classifies radiofrequency electromagnetic fields as possibly carcinogenic (Group 2B), and there are studies investigating the effects of prolonged exposure on biological processes such as sleep and oxidative stress.

What is the difference between ionizing and non-ionizing radiation?

Ionizing radiation (X-rays, gamma rays, high-energy UV) can strip electrons from atoms and damage cells. Non-ionizing radiation (radio, microwave, infrared, visible light) does not have that capacity, but can generate thermal effects and, according to ongoing research, potential long-term biological effects.

What part of the electromagnetic spectrum can we see?

The human eye only perceives visible light, a very narrow band between 380 nm and 700 nm in wavelength. This represents less than 0.0035% of the total electromagnetic spectrum. Everything else (radio waves, microwaves, infrared, UV, X-rays, gamma rays) is invisible to us.