Waves

Definition

Waves are oscillations that transfer energy through space or a medium, without the physical transfer of matter. In astronomy, light waves (electromagnetic waves) are crucial for observing and understanding celestial objects.

5 Must Know Facts For Your Next Test

1. Light behaves as both particles (photons) and waves, known as wave-particle duality.
2. The speed of light in a vacuum is approximately 299,792 kilometers per second (km/s).
3. Electromagnetic waves vary in wavelength and frequency; this variation creates the electromagnetic spectrum.
4. Visible light is just a small part of the electromagnetic spectrum, which also includes radio waves, microwaves, infrared, ultraviolet, X-rays, and gamma rays.
5. The Doppler effect describes how the wavelength of light changes due to the motion of an object relative to an observer.

Review Questions

Related terms

Electromagnetic Spectrum:

The range of all types of electromagnetic radiation based on their wavelengths and frequencies.

Photon:

A quantum particle representing a discrete amount of electromagnetic energy with no mass.

Doppler Effect:

A change in frequency or wavelength of a wave relative to an observer moving relative to the source of the wave.