Waves and Wavelengths

Waves and Wavelengths

• Waves transfer energy, not matter, from one location to another
• Examples include ocean waves, sunlight, and sound
• Seismic waves, light waves, and sound waves are all types of waves
• All waves have energy and transfer energy not matter
• The medium (substance a wave moves through) moves back and forth, but the wave travels through the medium

What is a Wave?

• A wave is a disturbance that moves energy
• Energy, not matter, is transferred
• The medium of a wave moves back and forth, while the wave moves through it
• The medium returns to its original position
• A wave's medium doesn't stay in one place

Types of Waves

• Seismic waves shake the ground during earthquakes
• Light waves travel through the universe, allowing us to see stars
• Sound waves are the sound we hear

Properties of Waves

• Wavelength: The distance between one point on a wave and the next identical point (e.g., crest to crest or trough to trough)
• Crest: The highest point of a wave
• Trough: The lowest point of a wave
  • Waves in nature, like in the ocean, move up and down, creating crests and troughs
• Frequency: The number of waves that pass a point per second; measured in Hertz (Hz)
  • Frequency is related to energy. More frequent waves require more energy to create them.
  • Middle C, for example, has a frequency of 261.6 Hz
• Waves can have varying lengths:
  • Ocean waves can be 120 meters (394 feet) long
  • Microwave ovens produce waves of 0.12 meters (5 inches)
  • Light waves have much smaller wavelengths

Electromagnetic Spectrum

• The electromagnetic spectrum displays various types of light waves, including radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays, arranged by wavelength
• Wavelengths can range drastically in size, from kilometers (radio waves) to millionths of a millionth of a meter (gamma rays).
• Human eyes can only perceive a tiny portion of the electromagnetic spectrum, which falls into the visible light range.