Let the speed 
of a closed curve on the unit sphere 
never vanish. Then the tangent indicatrix, also called the
tantrix,
 |
is another closed curve on 
.
If 
immerses in 
, then so will 
.
Tangent Indicatrix
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References
Solomon, B. "Tantrices of Spherical Curves." Amer. Math. Monthly 103, 30-39, 1996.Referenced on Wolfram|Alpha
Tangent IndicatrixCite this as:
Weisstein, Eric W. "Tangent Indicatrix." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/TangentIndicatrix.html