In this report you will read to find out things about infrared waves. Infrared waves were discovered in the early 19th century by an astronomer. It is part of the electromagnetic spectrum, between microwaves and visible light. Infrared radiation is widely used in many different aspects of life such as in remote controls, heating food and in night vision. Infrared waves can detect differences in temperatures and portray them in colors. Read on to find out more interesting facts about Infrared waves.
History
Infrared rays were discovered by William Herschel, an astronomer in the early 19th century. At the time it was discovered it was called 'Colorific Rays', the term Infrared appeared in the late 19th century. The word 'infra' literally means below so the term infrared means below red. Herschel used a prim to reflect light from the sun and therefore detected the infrared waves beyond the red part of the spectrum. The prism detected an increase in temperature recorded on a thermometer. He was surprised by the results so he called it 'Colorific Rays' to show the colors that represent temperatures.
Properties and Characteristics
Infrared radiation is part of the electromagnetic spectrum between the visible waves and the microwaves. Its wavelengths are varied in different wave ranges; it is between 0.7 micrometers and 300 micrometers. It is longer than visible light and the shorter than Terahertz radiation. Near infrared waves are closest which are near the visible light while the longer infrared waves are further away and are near the microwave region. The further away , the longer the wavelength gets and the size of the wavelength is equivalent to the size of a pin head or even smaller but the closer you get , the wavelength becomes shorter and its grows in size like a cell or in that range. The far wavelengths are usually thermal waves and they are the type we experience daily from the sun. All forms of heat are infrared waves which are emitted from natural sources like the sun or man-made sources such as light bulbs in all their forms. Many things give off infrared waves and most of them are natural and celestial like the sun, stars and galaxies. To be able to study these waves and why they are released and at what strength and what kind it is, NASA has sent satellites in space that have infrared detection sensors like "Landsat 7". These satellites detect the amount of infrared released and the type of infrared. The human body has temperature sensitive nerves on the skin that can tell the differences in temperatures which is why we sometimes feel cold or hot. The reason our bodies can tell the difference in temperature is because of the infrared waves that come in contact with the nerves. Short infrared waves are always cold or relatively warm.
Infrared Bands
The infrared spectrum is divided into seven parts or seven bands in the optical communications based on the availability of light sources and the materials that absorb infrared. The C band is the dominant wavelength in telecommunication networks while the S and L bands are based on less established technology and are not very common.
Band
Descriptor
Wavelength Range
O Band
The O Band is the original band of infrared and is the most common.
1260- 1360 mm
E Band
The E band is an extended version of the infrared wave and is generally longer than the original but still shorter than the S band.
1360-1460 mm
S Band
The S band is a short wavelength of the infrared waves and is the size of a cell.
1460-1530 mm
C Band
The C band is a conventional band, it isn't commonly found.
1530-1565 mm
L Band
The L band is a long wavelength of the infrared waves and is the size of a pin head.
1565-1625 mm
U Band
The U band is an ultra long wave that is the longest wavelength.
1625-1675 mm
*mm - Micrometers
Uses
Infrared waves are widely used across the world in many different diverse ways. They are used in a lot of systems such as Navigation systems and Alarm systems where PIR "Passive Infrared" detectors are able to detect infrared radiation coming off intruders. They are also used in Weather forecasting where the infrared waves in satellites detect weather patterns coming off the Earth such as rain, clouds, storms or heat waves. Satellites take images of the Earth that are extremely clear as they focus on weather patterns only. Also an extremely important use for infrared waves is in technology like mobile phones, computers and Wifis, infrared waves are transmitted from a source to its counterpart and is received through a sensor. Infrared waves pass easily through the air. Infrared waves can be detected using special equipment such as Night Vision Aids that are used at night or in dark areas. Night Vision Aids include special Night Goggles that are able to detect heat waves coming off objects such as humans and vehicles. Each object has a distinct infrared radiation so they can be easily identified. Remote controls use short infrared waves that do not give off any heat, the infrared waves that are used in remote controls are near the visible light so they can be detected by sensors that they are controlling. We think that because infrared waves are short and do not give off any heat they are an effective way of controlling items. Physiotherapy is another field where infrared is used, where physiotherapists use special infrared heat lamps. These lamps are then directed at sport injuries and the infrared penetrates the skin to help heal the muscles strain. Infrared radiation is used in toys, heating food and in Infrared Saunas.
Advantages and Disadvantages
Advantages of infrared rays is that it uses low power and has a high level of security. It is found in many portable devices and there is no signal interference from other waves. Infrared waves can be used in adjacent rooms; it is not affected by radio transmissions. On the other hand there are some disadvantages to using infrared waves such as, a long exposure to infrared waves especially strong radiation can cause problems in our vision and eyes. Another downside is that it is easily blocked by any tangible object. It has a short wave range and sometimes extreme weather affects it. While transmitting things it has a low speed but it has a wide bandwidth and the best sound production. The quality of infrared waves varies with the company and manufacturer. Large areas require multiple emitter panels. High intesity or fluorescent light can cause interference in transmissions.
Dangers
Infrared rays can be rather dangerous to the human body after long exposure as it affects the eyes and eyesight drastically. Special eyeglasses must be worn when dealing with exposed infrared rays. In some extreme cases it can cause cancer or blindness. The human body acts as an antenna to the infrared rays so they may mess with the body's natural electricity that is caused by the brain. A magnetic field surrounds any living creature that has acted as an antenna or a passage for infrared waves.
How can we see using the Infrared?
We can see using infrared waves using special goggles or thermo graphic cameras. Thermo graphic cameras detect radiation that is released from any object and captures it in a certain color that ranges from blue to red with cold and hot respectively. Since infrared radiation is emitted by all objects based on their temperatures, according to the black body radiation law, thermographs make it possible to see any object without visible illumination. Everything gives off infrared rays including ice cubes and extremely cold objects. Some animals have special vision that helps them detect infrared waves using their eyes to help capture their prey such as snakes but humans do not have infrared detection senses. We think humans don't have infrared detection because they do not need to hunt on anything to survive and they have basic vision that shows everything and isn't limited like a snake's would be.
Heating
Infrared radiation can be used as a slow heating source. For example it is used in infrared saunas to heat the resident and the air surrounding him. It can be used to remove ice from the wings of an aircraft. Infrared can be used in medical fields like the far infrared thermometric therapy clothing that provides compressing support and healing warmth that assists in soothing painful joint injuries or soothing pain. Infrared can be used in cooking and heating food as it mainly heats the translucent, absorbent objects, rather than the air around them. Infrared heating has become recently popular with an increase in industrial demands such as forming of plastics, making something more resolute, plastic welding, and print drying.
Night Vision
Infrared gives us the ability to see in dark places where there isn't enough light. Night goggles can be worn to see infrared rays. Night goggles take photos and turn them into electrons and then back to light.
Making Infrared Pictures
Did you ever see a picture where the colors are mainly hot or cold like red or orange and the thing pictured doesn't have its original color? Those kinds of pictures are usually infrared pictures. Infrared pictures are taken using special cameras or films that are able to detect the differences in temperatures using the infrared waves that are given out by the object photographed. The differences in colors on the image represents the differences in temperature for hot colors like red and orange and all their shades represent hot waves that are further away and cold colors like blues and all their shades represent cool waves that are nearer to us.
What does the Infrared show us?
Infrared gives us the ability to see in the dark and to see how hot an object is in thermal images. It can help in detecting a disease especially ones that have a symptom of high fever. It can help geologists and meteorologists in finding out information about the Earth's weather patterns and how the Earth was formed. The structure of the Earth can be detected based on how hot each layer is. Hot temperatures are shown in shades of red while cooler temperatures are shown in shades of blue. Infrared rays can be reflected such as off chlorophyll, the substance that gives plants its color.
Conclusion
Infrared rays were discovered in the early 19th century by William Herschel. They are in the electromagnetic spectrum between microwaves and visible light. Infrared rays have many uses in many fields ranging from medical uses to geology and meteorology. Infrared rays are used to detect temperatures coming off any body as everything in existence gives off some form of infrared. There are special goggles used to be able to see infrared and they are called Night Vision Aids. There are seven bands or layers to the infrared rays. Infrared can be hazardous to our health as it can cause blindness or damage to the eye. Some advantages of infrared are that it has a low price and a high security level but a disadvantage would be that it is easily blocked. Infrared waves are used in heating objects such as food or saunas, physiotherapists use the heat to heal sports related injuries.
