[/caption]During the 19th century, one of the greatest discoveries in the history of physics was made by an Scottish physicist named James Clerk Maxwell. It was at this time, while studying the perplexing nature of magnetism and electricity, that he proposed a radical new theory. Electricity and magnetism, long thought to be separate forces, were in actuality closely associated with each other. That is, every electrical current has associated with it a magnetic field and every changing magnetic field creates its own electrical current. Maxwell went on to express this in a set of partial differential equations, known as Maxwell’s Equations, and form the basis for both electrical and Magnetic Energy.
In fact, thanks to Maxwell’s work, magnetic and electric energy are more appropriately considered as a single force. Together, they are what is known as electromagnetic energy – i.e. a form of energy that has both electrical and magnetic components. It is created when one runs a magnetic current through a wire or any other conducive material, creating a magnetic field. The magnetic energy generated can be used to attract other metal parts (as in the case in many modern machines that have moving parts) or can be used to generate electricity and store power (hydroelectric dams and batteries).
Since the 19th century, scientists have gone on to understand that many types of energy are in fact forms of electromagnetic energy. These include x rays, gamma rays, visible light (i.e. photons), ultraviolet light, infrared radiation, radio waves, and microwaves. These forms of electromagnetic energy differ from each other only in terms of the wavelength and frequency. Those forms which have shorter waves and higher frequencies tend to be the more harmful varieties, such as x-rays and gamma rays, while those that have longer waves and shorter frequencies, such as radio waves, tend to be more benign.
In mathematical terms, the equation for measuring the output of a magnetic field can be expressed as follows: V = L dI/dt + RI where V is volume, L is inductance, R is resistance, I is charge, dI represents change in charge, and dt represents change over time.
Here are some articles about Magnetic Energy written for Universe Today.
Behind the Power and Beauty of Northern Lights
Magnetic Fields in Inter-cluster Space: Measured at Last
If you’d like more info on Magnetic Energy, check out these articles:
Wikipedia Entry on Magnetic Energy
More info about magnetic energy
We’ve also recorded an entire episode of Astronomy Cast all about Magnetism. Listen here, Episode 42: Magnetism Everywhere.
Sources:
http://en.wikipedia.org/wiki/Magnetic_energy
http://en.wikipedia.org/wiki/James_Clerk_Maxwell
http://en.wikipedia.org/wiki/Maxwell%27s_equations
http://fi.edu/guide/hughes/10types/typesmagnetic.html
http://farside.ph.utexas.edu/teaching/em/lectures/node84.html
http://science.jrank.org/pages/2489/Energy-Magnetic-energy.html