Parabolic Mirror, Illustration

All conic sections possess a mirror property which, in case of parabola, guarantees that the light emitted from a source located at the focus of a parabola and reflected off its inner surface travels along a straight line parallel to the axis of the parabola. The applet below is a simple illustration of this property.

The flashlights and automotive front lights have a light source at the focus of a parabolic mirror. Modern radio telescopes work on this principle as well but in reverse, collecting the rays from a distant source in the focus of a prabolic antena. Dish TV also works on this principle.

This applet requires Sun's Java VM 2 which your browser may perceive as a popup. Which it is not. If you want to see the applet work, visit Sun's website at, download and install Java VM and enjoy the applet.

What if applet does not run?

Conic Sections > Parabola

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