What is an electromagnetic spectrum?
The electromagnetic spectrum is a family of waves with a large number of common properties.
- Can travel through a vacuum
- Travel at the same speed through a vacuum i.e. the speed of light.
- Are transverse waves
- Transfer energy
- Can be reflected ,absorbed ,transmitted ,refracted and diffracted
Some of the properties of these waves change as their wavelength and frequency changes. The family is therefore divided into seven small groups.
What are these different properties used for? What are their Dangers?
Radio waves -> This property is used in TV’s and Radio’s. Large doses of radio waves are believed to cause cancer, leukaemia and other disorders.
Microwaves -> This property is used in Mobile Phones. Prolonged exposure to microwaves is known to cause "cataracts" in your eyes, which is a clouding of the lens, preventing you from seeing clearly (if at all!) Recent research indicates that microwaves from mobile phones can affect parts of your brain - after all, you're holding the transmitter right by your head.
Infrared-> This property is used in the TV remote control. The danger is overheating from too much Infra-Red radiation.
Visible Light -> Is used to see things. The danger is too much light can damage the retina in your eye. This can happen when you look at something very bright, such as the Sun. Although the damage can heal, if it's is too bad it'll be permanent.
Ultraviolet -> This is used in Fake Tan studios. The Dangers are large doses of UV can damage the retina in your eyes, so it's important to check that your sunglasses will block UV light but also can cause sunburn and even skin cancer. Fortunately, the ozone layer in the Earth's atmosphere screens us from most of the UV given off by the Sun.
X-Rays -> This property is used to look inside people without cutting into them. The Danger is X-Rays can cause cell damage and cancers. This is why Radiographers in hospitals stand behind a shield when they X-ray their patients. Although the dose is not enough to put the patient at risk, they take many images each day and could quickly build up a dangerous dose themselves.
Gamma Rays -> This property is used to Kill Cancer Cells. The Dangers of Gamma rays are they cause cell damage and can cause a variety of cancers. They can cause mutations in growing tissues, so unborn babies are especially vulnerable.
That's the end of the topic!
Drafted by Kin (Physics)