Microwaves: These are the same types used your microwave oven you use at home. They are also used in radars, and in space. Astronomers use them to find out about our galaxy. It penetrates N on our earths atmosphere. The wave length is 10^-2, and the frequency is 10^8.
Infrared: Infrared has a heating effect. Our own skin emits it this is why you can see someone when you have night vision goggles on. The police use infrared cameras on criminals so they can catch them. Remote controls are also used with infrared radiation. It penetrates N also. Its wavelength is 10^-5, and the frequency is 10^12.
Visible: This is the part that we see; it is emitted by many things, from light bulbs to stars, also by fast moving particles hitting each other. The wave length is 0.5 x 10^-6, the frequency is 10^15.
Ultraviolet rays: The sun is a source of UV radiation this makes are skin tan and helps are body produce vitamin D. Stars and other hot gases in space emit UV radiation. The wave length is 10^-8, and the frequency is 10^16.
X-rays: Doctors uses these to look at bones, and dentists to look at teeth. It works by “firing” the photons into your body, the atoms in your flesh let them pass through but materials like metal “reflect” them. Since calcium is a metal we get an accurate image of your bones. Hot gases in the universe also emit X-rays.
The wave length for X-rays are 10^-10, and the frequency is 10^18.
Gamma-rays: Radioactive materials give off gamma-rays, radioactive materials can be natural or man made. Large Particle Accelerators can generate gamma-rays. But the biggest contributor to gamma radiation is the universe; it makes it in hundreds of ways. The wave length is 10^12, the frequency is 10^20.
What is the difference?
The waves may have different lengths, frequencies’s and are produced in different ways but they are all fundamentally the same thing. They are electromagnetic radiation.
Electromagnetic radiation in terms of a stream of photons, that is weightless and travels in a wave like pattern at the speed of light. Each photon has a certain amount of energy, photon energy, all EM radiation consist of these photons. The only difference between them is the amount of energy found in the photons. Radio has the least and microwaves a little more, it continues this way with gamma having the most energy.
The electromagnetic spectrum can be expressed in terms of energy, wavelength, or frequency. Each way of thinking about the EM spectrum is related to the others in a precise mathematical way. So why do we have three ways of describing things, each with a different set of physical units? After all, frequency is measured in cycles per second (which is called a Hertz), wavelength is measured in meters, and energy is measured in electron volts.
Are they Dangerous?
Some electromagnetic radiation can be harmful.
When we use microwaves it heats up our food quick and easy, however, it has been found that when it is heated it can destroy some of the goodness in food, e.g. minerals and vitamins. However the danger is not that great, in this country we use the precautionary principle, which means that if we don’t know how great the danger is we don’t use it.
Mobile phones also use microwaves, there has been a connection made with brain disease and the use of a mobile phone at a young age. This, however, has not been proven so we use the ALARA rule. Which means; as low as reasonably achievable. For example, when you use your phone you could use a hand free set or text more, so the phone is away from your head.
Ultraviolet radiation can also be harmful. The sun is a source of UV radiation, when you go out in the sun UV radiation causes burns. In some cases it can even cause skin cancer. To protect your self you can; wear sun block, sit in the shade, or wear a T-shirt.
X-rays can be quite dangerous. There has been a link made between having X-rays and getting cancer, and although they doctors need to use them they are harmful. To protect yourself you need to try not to subject yourself to unnecessary radiation.
Gamma-rays are not very common but can be extremely dangerous. This is because of the amount of energy in gamma-rays. A gamma-ray photon has enough energy to damage the cells in your body and make them radioactive, and gamma rays easily penetrate your body. Gamma-rays are not very common so you won’t come in contact with them, but if you do wear a lead vest.
