Definition: Study of everyday phenomena, matter, energy, and laws of nature.
Light: Electromagnetic radiation in a specific portion of the electromagnetic spectrum.
James Clerk Maxwell (1831-1879): Made significant contributions to electromagnetic wave theory.
Light as a transverse wave composed of oscillating electric and magnetic fields at right angles to each other.
Radiates energy in the form of electromagnetic (EM) waves.
Vibrating electric charges create changing electromagnetic fields capable of wave propagation.
Speed of EM Waves: 3 x 10^8 m/s.
Photons: Bundles of wave energy; types of EM waves defined by energy carried by photons.
Wave Characteristics:
Crest: Highest point.
Trough: Lowest point.
Amplitude: Maximum displacement.
Wavelength: Distance between crests.
Frequency: Number of waves per second (measured in Hertz).
Range of different wavelengths including:
Radio waves (longest wavelength, lowest frequency).
Microwaves.
Infrared.
Visible light (ROYGBIV).
Ultraviolet.
X-rays.
Gamma rays (shortest wavelength, highest frequency).
Longest wavelength; produced by vibrating electrons in an antenna.
Higher frequency and energy than radio waves.
Not visible but felt as heat; relates to temperature.
Separated into colors by prisms; includes red (longest wavelength) and violet (shortest wavelength).
Emitted by the sun; shorter wavelengths than visible light.
Types: UVC, UVB, UVA (increasing wavelength).
Discovered by Wilhelm Roentgen; useful for medical tests.
Emitted by stars; very dangerous, blocked only by lead/concrete.
As energy increases, frequency increases and wavelength decreases.
Electromagnetic radiation can be both useful and hazardous.