The Nature of Light
Guiding Questions
Determining the Speed of Light
Light travels through empty space at a speed of 300,000 km/s
Slide 5
Light is electromagnetic radiation and is characterized by its wavelength ()
Wavelength and Frequency
Slide 8
Slide 9
Three Temperature Scales
An opaque object emits electromagnetic radiation according to its temperature
Slide 12
Wien’s law and the Stefan-Boltzmann law are useful tools for analyzing glowing objects like stars
Wien’s Law
Slide 15
Stefan-Boltzmann Law
Slide 17
Light has properties of both waves and particles
Photons
Each chemical element produces its own unique set of spectral lines
Slide 21
Kirchhoff’s Laws
Slide 23
Slide 24
Slide 25
Slide 26
An atom consists of a small, dense nucleus surrounded by electrons
Slide 28
Slide 29
Spectral lines are produced when an electron jumps from one energy level to another within an atom
Slide 31
Slide 32
Bohr’s formula for hydrogen wavelengths
Slide 34
Balmer Lines in Star Spectrum
The wavelength of a spectral line is affected by the relative motion between the source and the observer
Doppler Shifts
Key Words
Author: Michael Cohen
E-mail: mrcohe@ship.edu
Homepage: http://physics.ship.edu/~mrc/