In 1838 George Airy worked out the proof for the explanation given by Christian Huygens in 1678 that this curve was the catacaustic of a circle when the light source is infinity. The evolute of Cayley's sextic, this curve is essentially a two-cusped epicycloid formed by a circle of radius A rolling externally on a fixed circle of radius 2A. FTP nam
In 1838 George Airy worked out the proof for the explanation given by Christian Huygens in 1678 that this curve was the catacaustic of a circle when the light source is infinity. The evolute of Cayley's sextic, this curve is essentially a two-cusped epicycloid formed by a circle of radius A rolling externally on a fixed circle of radius 2A. FTP name this curve, given its modern name in 1878 by R.A. Proctor, who thought that its shape was reminiscent of a kidney.
In 1838 George Airy worked out the proof for the explanation given by Christian Huygens in 1678 that this curve was the catacaustic of a circle when the light source is infinity.
nephroid