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In December 2021, NASA launched its newest flagship telescope. Named after the administration’s second director, James Webb observes the universe in infrared (IR) wavelengths. However, this form of radiation isn’t the only way we peer through space.

Due to their positions just outside of our vision, we’ve had a great interest in the relationship between infrared vs ultraviolet. Their qualities introduce everything from heating to visibility to communication. Continue reading for the important aspects of each one and how we use them on the daily.

Infrared vs Ultraviolet: Side-by-Side Comparison

Discovery Date18001801
Discovered byWilliam HerschelJohann Wilhelm Ritter
Frequency300Ghz – 400THz800THz – 30PHz
Wavelength780nm – 1mm400 – 180nm
Energy Level1.2meV – 1.7eV3 – 124eV
ApplicationsNight vision, tracking, heating and cooling, communications, meteorology, astronomyPhotography, electrical, analytics, material science, astronomy
Possible HazardsDamage to the eyesDamage to the eyes and skin, malignant melanoma

Infrared vs Ultraviolet: What’s the Difference?

Let’s have a look at what sets these two types of electromagnetic radiation apart.

Infrared Origin

In 1800, the German-born British astronomer William Herschel discovered heat sources from outside the visible range of light. Experimenting with what would inspire the spectrometer, the scientist was able to test the temperature of each color of light.

When the temperature continued to rise beyond red light, Herschel suggested that the energy came from radiation rather than brightness. As the astronomer’s experiments support, IR radiation comes from objects that produce heat.

This is a result of several actions that can cause it to activate and create friction. This doesn’t require a hot temperature to emit radiation; any object that releases heat of minus 450 degrees Fahrenheit or higher emits infrared light.

Infrared Spectrum

visible light vs infrared
Infrared light is electromagnetic radiation with wavelengths longer than those of visible light.

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Part of the low-frequency end of the electromagnetic spectrum, infrared light finds its place between microwaves and visible light. Researchers usually measure this non-ionizing radiation using its wavelengths or frequency due to its low energy levels.

When considering its wavelength, IR typically ranges from 780nm – 1mm. This correlates with a frequency range of 300Ghz – 400THz and an energy level of 1.2meV – 1.7eV. For an idea of how large infrared can range, its average wavelength measure the diameter of a human hair.

Infrared Applications

Due to its range entering a designation involving heat sources, IR radiation has several uses. Usually, this type of energy is used in night vision goggles, which use sensors that paint images based on different wavelengths.

However, you don’t need to participate in covert operations to use infrared regularly. Common household objects such as toaster ovens and television remotes use IR in their functions. 

Infrared Dangers

While infrared is usually related to heat, it’s not likely that it’ll hurt you. Although some objects as hot as 3,200 degrees will produce NIR waves, they won’t burn.

Take care not to expose your eyes to those waves; high-frequency IR radiation can cause damage to retinas and even blindness in some cases. Overall, this type of radiation is relatively safe with regular amounts of exposure.

Ultraviolet Origin

infrared vs ultraviolet
Ultraviolet (UV) light has shorter wavelengths than visible light.


Following the discovery of infrared rays on the opposite side of the visible light spectrum, German chemist Johann Wilhelm Ritter worked with the polarities in the forces of nature. Working with silver chloride paper, Ritter discovered that its makeup reacted faster with the energy beyond violet light than it did with violet itself.

The chemist called these frequencies deoxidizing rays for their ability to change the chemical balance in materials. Entering this range of frequency on the electromagnetic spectrum, UV light requires enough electrical activation that it can ionize atoms.

When electric discharges pass through gasses, they produce low-frequency radiation. This is where we start to see the beginnings of harmful rays.

Ultraviolet Spectrum

On the EM spectrum, ultraviolet light finds itself located between the violet range of visible light and X-rays. Although we start to see increases in energy at this range, scientists still choose to measure this type of radiation using wavelengths and frequencies.

UV light often includes wavelengths of 400 to 180nm. This relates to a frequency range of 800THz – 30PHz (petahertz) and an energy range of 3 – 124eV. Compared to infrared light, these wavelengths are much smaller; the average size of ultraviolet light measures the diameter of the rhinovirus.

Ultraviolet Applications

The UV range finds itself in a strange transitional phase; its energy levels are high enough to ionize, but its wavelengths aren’t small enough to provide precise imaging. Thus, UV radiation sees limited use.

Its applications tend to range from fluorescent light sources to delicate forms of skin treatment. However, its use in the Hubble Telescope is a major cause for the resurgence of space exploration.

Ultraviolet Dangers

While it features less prominent ionizing properties when compared to X-rays or gamma rays, UV can still have adverse effects on the human eye and skin. Exposure to significant amounts of UV-B or UV-C can result in sunburns, collagen damage, and some forms of skin cancer. Most notably, 92% of malignant melanoma has a direct relationship with ultraviolet radiation.

Infrared vs Ultraviolet: 5 Must-Know Facts

  1. Both infrared and ultraviolet (UV) border the visible light range of the electromagnetic spectrum; there are trace frequencies of each that we can see.
  2. IR light is commonly associated with heat sources.
  3. UV radiation is highly dangerous to our skin in high doses, but over 95% of it attenuates in the atmosphere.
  4. The James Webb Space Telescope observes the universe in near-IR, which allows it to peer through space dust.
  5. Ultraviolet radiation is so powerful that it can alter the composition of atoms.

Infrared vs Ultraviolet: Which One Is Better?

When comparing infrared vs ultraviolet, they seem equal at first glance; both forms of radiation have a spot adjacent to the visible light spectrum, which gives them a more natural setting in daily life. Additionally, their non-ionizing vs ionizing properties each come with benefits and weaknesses.

Where infrared starts to look better is in its applications. Because it’s closely related to heat properties, the radiation finds more uses in thermal imaging, heating and cooling, and more. And because IR is one of the faster non-ionizing portions of the EM range, we tend to use it in a variety of household tools.

UV continues to prove less appealing when we consider its hazards. Because its energy levels introduce the ability to alter the composition of atoms, UV has the potential to cause real damage to the eyes and skin. At frequencies of this range, skin cells can even start to break down, causing cancer.

Infrared vs Ultraviolet: Further Reading

As close as they are to the slim range of light that we can see, it’s important to know the difference between infrared vs ultraviolet. Knowing how each of these frequencies plays a role in our lives helps us understand how we should use them. For more applications of the electromagnetic spectrum, check out the articles below.

Infrared vs Ultraviolet: How Do They Compare? FAQs (Frequently Asked Questions) 

Which is more harmful UV or infrared?

Due to its energy level and ionizing capabilities, ultraviolet presents more hazards than infrared. With enough exposure, UV can cause physical damage to the eyes and skin. Most notably, ultraviolet radiation can cause some forms of skin cancer, including malignant melanoma.

What is the difference between ultraviolet and infrared?

Ultraviolet and infrared differ in their lengths, frequencies, and power levels. The difference between the two is great enough that ultraviolet starts to take on ionizing qualities.

Which is hotter infrared or ultraviolet?

Infrared is hotter than ultraviolet because they emit from larger objects, which involves the agitation of several particles or atoms. However, the size of UV waves produces more energy overall.

Is the sun ultraviolet or infrared?

According to the National Oceanic and Atmospheric Administration, 49% of the sun’s emitted energy is infrared while 7% is ultraviolet.

What are some uses for infrared?

Infrared has a variety of applications which include night vision goggles, toaster ovens, remote controls, weather tracking, and IR astronomy.

How do we use ultraviolet?

Because of its ionizing qualities, ultraviolet has limited applications. Most commonly, UV is used in fluorescent lighting and imaging. The radiation also finds uses in photography, bioluminescence, and some skin treatment.

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  • Live Science Available here: https://www.livescience.com/50260-infrared-radiation.html
  • University Corporation for Atmospheric Research Available here: https://scied.ucar.edu/learning-zone/atmosphere/ultraviolet-uv-radiation#:~:text=Ultraviolet%20radiation%20oscillates%20at%20rates,12%20hertz)%20and%2030%2C000%20THz.
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