(a.k.a. What's REALLY In Your Microwave)
What are Electromagnetic (EM) Waves?
- Radio waves- are used in radios and televisions
- Infared light- used in night vision goggles and television remotes
- Ultraviolet light- given off by stars, causes sunburns, detects forged bank notes
- Visible light spectrum- colors, emitted by the Sun and lightbulbs
- Microwaves- used to cook food and find out more about nearby galaxies
- X-rays- used for medical purposes to look at bones and to see through objects
- Gamma rays- used by doctors to see inside bodies and to kill cancer cells
Where Do Electromagnetic Waves Come From?
Some examples of things that cause electromagnetic waves are radios, microwaves, and light sources.
How Does Frequency Affect EM Waves?
Electromagnetic waves with an extremely high frequency sometimes make atoms vibrate so fast it flings the electrons off of atoms. This can be extremely damaging to cells and the lifeforms they create. Fortunately, Earth's atmosphere keeps most dangerous EM waves from reaching the surface.
How Are Electromagnetic Waves Different From Mechanical Waves?
Most Electromagnetic waves are invisible. Our eyes can't detect them. The only EM waves humans can see are those in the visible light spectrum (colors). The color white is actually all frequencies in the visible light spectrum hitting your eye at once.
This image shows the relation between electric and magnetic waves.
This image shows several things- how the wavelength affects what the wave is called, whether a certain kind of wave penetrates Earth's atmosphere or not, and the temperature needed to reach a certain kind of EM frequency.
How Are EM Waves Different from Mechanical Waves?
Electromagnetic waves are also different from mechanical waves in that EM waves are vibrating electric and magnetic fields, while mechanical waves consist of vibrating particles.