Brain Makeover #3: Electricity and Magnetism (by the 76ers Cheerleaders)

Electricity and Magnetism are Two Sides of the Same Coin.

Professor James Trefil (author of Science Matters, Why Science?, and 30 other books on science literacy) identified 18 key science concepts every adult should know to be a science literate. We’re here to reintroduce adults to science, in a fun way! It’s all part of our Brain Makeover project to increase adult science literacy. Here’s concept #3, presented by 76ers Cheerleader Jenn and explained by Professor James Trefil.  We’ll post one each week (more or less) and it to the Brain Makeover collection.

#3. Electricity and Magnetism are Two Sides of the Same Coin.

Electrical charge can be either positive or negative, and the electrical force operates in such a way that the force between like charges is repulsive while the force between unlike charges is attractive. (see 3-yr-old Teddy’s hair for an example.)

Magnets have north and south poles, and the magnetic force is such that like poles repel each other while unlike poles attract. There are no isolated magnetic poles in nature—whenever there is a north pole, in other words, there is also a south pole.

Whenever electrical charges move (i.e. whenever an electric current flows) a magnetic field is produced. This is the basic working principle of the electromagnet and the electric motor.

Whenever a magnetic field changes near a conductor, an electric current will be produced in the conductor. This is the basic working principle of the electric generator, the device used to produce almost all electricity used in modern society.

These four statements, when written in mathematical form, are called Maxwell’s Equations and summarize the behavior of electric and magnetic phenomena. The equations predict the existence of electromagnetic waves—alternating electric and magnetic fields that move at the speed of light. Radio, microwave, infrared radiation, visible light, ultraviolet light, X rays, and gamma rays are all examples of electromagnetic waves.

  • The engineering aspect of electromagnetism comes out when you’re bundling wires together, as, for example, in a rocket. When electricity passes through a wire, that signal has the potential to flow through other wires nearby as well. Once this problem was understood, engineers had to learn to test for electromagnetic interference (EMI). Otherwise, signals from one cable/wire could interfere with signals sent on another wire, and that would be a Bad Thing.

    Even English majors can learn this stuff, given time!

    /b

  • The engineering aspect of electromagnetism comes out when you’re bundling wires together, as, for example, in a rocket. When electricity passes through a wire, that signal has the potential to flow through other wires nearby as well. Once this problem was understood, engineers had to learn to test for electromagnetic interference (EMI). Otherwise, signals from one cable/wire could interfere with signals sent on another wire, and that would be a Bad Thing.

    Even English majors can learn this stuff, given time!

    /b

  • http://soonereyo.blip.tv/#1826380
    So….can your Brain Makeover Cheerleaders do this?

    I love your site! Science Cheerleader rocks the nation! 🙂

  • http://soonereyo.blip.tv/#1826380
    So….can your Brain Makeover Cheerleaders do this?

    I love your site! Science Cheerleader rocks the nation! 🙂

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  • Of course, when you rewrite Maxwell's equations with time as the fourth dimension, they collapse into one equation, and when you rewrite general relativity with five dimension, the Maxwell tensor emerges as the curvature of the fifth dimension 😉

  • Of course, when you rewrite Maxwell’s equations with time as the fourth dimension, they collapse into one equation, and when you rewrite general relativity with five dimension, the Maxwell tensor emerges as the curvature of the fifth dimension 😉

  • thx
    your sharing ,i learn a lot form it