Electromagnetic Spectrum

The electromagnetic spectrum covers a wide range of wavelengths and photon energies.

Two types of waves Transverse (no medium required) and Compression (must have a medium)

Wavelength:the distance between two identical points on two adjacent waves

Frequency is the number of wave crests that pass a point during one second.

These waves go from Large to small Radio Microwaves Infrared Visible Light Ultraviolet X-Rays Gamma Radiation

Electromagnetic waves are produced by the motion of electrically charged particles Particle Wave Duality: Electomagnetic radiation acts as a wave but also as a particles (“Photons” which is a stream of particles that has no mass.)

Visible Light Why is the sky blue?

Why is the sky blue? Rayleigh Scattering

Rayleigh Scattering: light hits gas molecules and the different frequencies are all effected differently. Higher frequencies (blue) are absorbed much more often then lower frequencies (red)

The gas will eventually radiate the blue light back out scattering it out making the sky appear blue.

Why do you get different colors at sunset or when there are more clouds in the sky?

Ticket out the door 1. What is the largest wavelength we know about? 2. Are light wave transverse or compression waves? 3. Why is the sky blue?