|Electricity · Magnetism|
Quantum mechanics developed from the study of electromagnetic waves, which include visible light seen in the colors of the rainbow, but also other waves including the more energetic and higher frequency waves like ultraviolet light, x-rays, and gamma rays plus the waves with longer wavelengths including infrared waves, microwaves and radio waves.
Some types of electromagnetic radiation, such as X-rays, are ionizing radiation and can be harmful to your body. Ultraviolet rays are near the violet end of the light spectrum and infrared are near the red end. Infrared rays are heat rays and ultraviolet rays cause sunburn.
Mathematical formulation[change | change source]
In physics, it is well known that the wave equation for a typical wave is
The problem now is to prove that Maxwell's equations explicitly prove that the electric and magnetic fields create electromagnetic radiation. Recall that two of Maxwell's equations are given by
Note: the proof involves making the substitution
The equations above are analogous to the wave equation, by replacing f with E and B. The above equations mean that propagations through the magnetic (B) and electric (E) fields will produce waves.
Related pages[change | change source]
References[change | change source]
- This is always defined as the speed of propagation in a vacuum Speeds through various material substances vary.
- Hecht, Eugene (2001). Optics (4th ed. ed.). Pearson Education.
- Serway, Raymond A.; Jewett, John W. (2004). Physics for Scientists and Engineers (6th ed. ed.). Brooks/Cole.
- Tipler, Paul (2004). Physics for Scientists and Engineers: Electricity, Magnetism, Light, and Elementary Modern Physics (5th ed. ed.). W. H. Freeman.
- Reitz, John; Milford, Frederick; Christy, Robert (1992). Foundations of Electromagnetic Theory (4th ed. ed.). Addison Wesley.
- Jackson, John David (1975). Classical Electrodynamics (2nd ed ed.). John Wiley & Sons.
- Allen Taflove and Susan C. Hagness (2005). Computational Electrodynamics: The Finite-Difference Time-Domain Method, 3rd ed.. Artech House Publishers.
Other websites[change | change source]
- Electromagnetism - a chapter from an online textbook
- Electromagnetic Waves from Maxwell's Equations on Project PHYSNET.
- Ecolibria:More information and testing for EMR in Australia
- Conversion of frequency to wavelength and back - electromagnetic, radio and sound waves
- eBooks on Electromagnetic radiation and RF
- The Science of Spectroscopy - supported by NASA. Spectroscopy education wiki and films - introduction to light, its uses in NASA, space science, astronomy, medicine & health, environmental research, and consumer products.