For some the electromagnetic spectrum is a interesting thing to talk about however not many of us are familiar with what it actually is.
The electromagnetic spectrum is a name given to a single particle the photon, which has a plethora of different wavelengths and energy levels that it can take on. A vast majority of the world is fondly familiar with but a small fraction of the spectrum which we call the visible spectrum.
This includes the red, orange, yellow, green, blue, and purple and everything in between. Go beyond or either ends of this part of the spectrum and we humans aren’t able to see them.
As you can see from the above photo the spectrum has a broad range and it is baffling how much of a small portion we are capable to see. Being the brilliantly minded creatures we are, devices which allow us to see parts of the spectrum which we can’t.
For example infrared cameras allow us to view the world in infrared. Police helicopters are equipped with such cameras to allow them to pierce through the darkness and view the world of temperature.
The following will consist of information about the parts of the spectrum starting from the lowest energy level to the greatest.
Without this part of the spectrum it would be hard to imagine a world where they didn’t exist. These waves are the lowest energy baring but they have the largest wavelengths. It is a good thing to remember that as the wavelength decreases or gets smaller the energy of that particular photon increases.
Radio waves are often used in communication devices like, you guessed it radios. These photons often have wavelengths such as that which the picture shows. Often such photons have wavelengths the size of buildings or houses.
Television and radio use this part of the spectrum in order to transmit images and sound. Radio waves are effected by a part of the atmosphere called the ionosphere. This layer of the atmosphere is full of charged particles which cause the radio waves to curve back down to the earth. This is handy when transmitting signals to receivers who are not in sight.
Radar which is actually an acronym which stands for Radio Detection and Ranging uses anywhere from 10-100 meter wavelengths.
Microwaves are a bit more energetic compared to radio waves. Such photons were also used in communications like television before the advent of fiver optic cable. These waves were often used to carry phone calls among other things.
Many of us will know microwaves as the thing that heats up our food in that metal box which is also called a microwave. Microwaves as one could guess especially from the ones that heat up food aren’t the nicest things to get hit with. Microwaves are contained inside the microwave because they bounce off of flat metal sheets. Luckily the mesh we see on microwave doors protects us because the photons are unable to get through the small metal holes.
The wavelength of microwaves are about 120 mm and those holes are roughly 2 mm which means they cannot fit.
Infrared radiation is often recognized by infrared cameras which see heat. Everything that is hot gives off infrared radiation. Infrared radiation is also one of the three ways heat is transferred from one place to another.
Convection and conduction are also means for heat to be transferred. Conduction is what allows you to cook on a stove. The heat coming from the flame is absorbed by the pan and conduction is what allows the heat to spread across it.
Convection is best described as the type of heat you feel when standing next to a fire. Anything above 5 Kelvin or -450.67 Fahrenheit emits infrared radiation. It is often times shown in films that if one were to be exposed to space they would freeze. However that is not the case. Once exposed to the near vacuum of space heat has only one way to leave your body. That way is through the thermal energy leaving your body via infrared radiation which is the least efficient means of transferring heat. You would actually die by suffocation before you freeze.
Just a little bonus fact, nearly all of the energy from the sun is able to hit your body and have full effect. So this means the moisture from your eyes would evaporate. Oh and don’t forget to exhale before you enter the vacuum otherwise your lungs would burst. And no you wouldn’t explode.
Ultraviolet light is past the visible light in terms of energy. Everyone knows that this type of radiation is the cause of skin cancer and sunburns. The reason is because ultraviolet radiation has enough energy in the particles to break chemical bonds. These bonds are in things like your skin which once effected can become burnt.
Melanin is the bodies natural defense against UV radiation. The pigment absorbs UV radiation and disperses it as heat. Furthermore since UV radiation is ionizing which means it can cause electrons to leave atoms making them more reactive, it can effect the DNA of some cells which later down the road can develop into skin cancer.
It is important that you wear sunscreen and sunglasses to protect yourself from these damaging photons.
X-rays are both dangerous and helpful at the same time. X-rays come in different varieties the hard x-rays and the soft x-rays. Hard x-rays have higher energies while the soft ones have smaller energies.
They are given their name because of their use. The radiographic image used by doctors uses x-rays to view inside the body. There are other uses in astrophysics and astrology.
The most powerful parts of the electromagnetic spectrum is gamma rays. These high energy particles are most commonly associated with nuclear weapons. Particles like these are released by atomic nuclei.
There are many different means by which these particles can be created. Most know that these particles can be emitted during nuclear explosions but they also can be emitted by lightning.
Gamma rays are a bit tricky to detect because their wavelengths are small enough to pass through the space in between atoms of the detector. So gamma ray detectors are made with densely packed crystals. When a gamma ray hits an electron in the crystal created charged particles which then can be detected by the sensors.
Gamma rays come from space all of the time. Stars, black holes, pulsars and other celestial bodies produce these gamma rays.
That’s a lot of stuff!
The electromagnetic spectrum is vast in diversity and is constantly around us. So many things make up the spectrum itself and yet we are only capable of seeing such a small percentage of it. Yet we utilize most of it to better science, advance technology, and study the amazing world we live in.