Electromagnetic Waves
Elena Marshel
What's the Difference?
How are they Formed?
The Spectrum
Gamma Rays
Gamma ray waves have the highest frequency (higher than 3 x 1019 Hz) and the lowest wavelength (less than .01 nanometers) of all electromagnetic waves. These waves cannot be seen or felt, and are the product of radioactive atoms, but they have proven to be very useful. Gamma rays are used to kill cancer cells in patients, as well as to sterilize medical equipment. However, overexposure is very dangerous, and can cause an abnormality in cells that could lead to the forming of cancerous tumors. Pictured to the left is an image of the bursts of gamma rays that have been observed in space.
X-rays
X-rays have the second highest frequency (3 x 1016 - 3 x 1019 Hz) and the second lowest wavelength (.01 to 10 nm) on the electromagnetic spectrum. Like gamma rays, they cannot be seen or felt, and they're also used in the medical field. You've probably heard of someone having their x-ray taken, or maybe had one taken yourself. That's because x-rays are used to get pictures of bones in order to address possible fractures or breaks in them, as x-rays will pass easily through soft tissue like your skin and organs, but have a much harder time passing through hard surfaces like your bones. The reflections of the x-rays are read and used to create a picture of your skeleton. However, also like gamma rays, high exposure to these waves can cause cancer, which is why such care is protective care is taken when using them for medical purposes.
Ultraviolet Waves
Visible Light
Infrared
Infrared waves are what makes the technology for toasters and ovens possible. With a frequency of 3 x 1011 - 4 x 1014 Hz and a wavelength of 710 nm - 1 mm, we can feel infrared waves as heat. But they don't just work to help you make a toast! Infrared waves are used to create optical fiber technology, which is used in a wide range of things, from military drones and trains to decorative Christmas lights. Infrared is also used to create thermal vision. As we feel infrared waves as heat, devices that can pick up the waves can tell you the temperature of whatever it's viewing (a thermal vision image is pictured to the left).
Microwaves
Microwaves, besides, obviously, being used in microwaves by using their energy to heat up food, were crucial in the creation of a good deal of important technology. Their frequency of 3 x 109 - 3 x 1011 Hz and their wavelength of 1 - 100 millimeters enable a portion of them to be able to pass through the earth's atmosphere in order to reach satellites and other spacecrafts, which creates a way for communication between those on earth and the astronaut during space travel, as well as being able to transmit mobile phone signals.
Radio Waves
With the lowest frequencies of less than 3 x 1019 Hz and highest wavelengths of more than 1 millimeter, radio waves are necessary for many of our daily activities. Being very susceptible to diffraction and able to be transmitted over uneven terrain, they are used to transmit television programs, as well as radio programs. Those waves with low frequencies can even be reflected off the ionosphere and back down to earth in order to reach very far distances, bypassing the usual problems caused by the curve of the earth.