PURPOSE: To show that straight strings that are everywhere tangent to a hyperboloid approximate the hyperboloid.
DESCRIPTION: Twist the two spools in opposite directions to produce a changing hyperbola. Hold heavy string taught across hyperbola as shown in the photograph.
SUGGESTIONS: This device can be used as a model of light propagation in relativistic space-time.
REFERENCES: (PIRA unavailable.)
EQUIPMENT: Spool with nylon strings, as photographed.
SETUP TIME: None.
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