Russell Kightley Media Science Gifts > MATHS collection > Sine
Sine wave and cosine wave traced out by a rotating wheel. SINE WAVES (y = sin x) are ubiquitous. They represent the behaviour of a simple oscillator. This graphic illustrates the relationship between a circle (the red wheel) and the phase (stage) of the sine wave. As the wheel rotates the attached horizontal pointer traces out a sine wave on the purplish screen. The maximum amplitude of the wave is the same as the diameter of the circle (wheel). The height of the wave at any point depends on the sine of the angle that the radius of the circle (yellow line) makes with a horizontal plane (not shown). This is a still taken from an animation (you can see it at RKM.COM.AU) that illustrates the creation of these waves. Ideal gifts for nerds of all kinds.