ϖ is derived from the lemniscate of Bernoulli, which is defined by distances from two points.
Is there an analogous constant that is derived from a shape defined by distances from three points?
ϖ is derived from the lemniscate of Bernoulli, which is defined by distances from two points.
Is there an analogous constant that is derived from a shape defined by distances from three points?
Let’s call it a trilemniscate. ;)
Here’s a 3d plot of it. If you rotate to view it from +Z downward, then you’ll see the trilemniscate, which is where the volume intersects with the XY plane. Note I subtracted 1 from the product in order to visualize the plane intersection. (And you can turn off the 3 points version and turn on the 2 points version to compare.)
https://www.desmos.com/3d/dl9v2vqbqb
One interesting note about 2 points vs 3 points. The area inside the lemniscate and trilemniscate is the same! (True for more points, as long as they’re evenly space on a circle). The perimeter, of course, goes to infinity as you add more points.
2 points always have a shortest path between each other, so the constant is about this fact. For 3 points you have the whole universe of possible triangle shapes to contend with.
For instance, if you're constrained to travel along the surface of Earth, your shortest path is going to travel along a great circle, rather than pass through the interior of the sphere.
That said, you could, for instance, pick the three vertices of an equilateral triangle (using the Euclidean distance as your metric of choice, as we do in order to derive the lemniscate and the circle), and again deal with the product of the distances from each vertex.
You again start with small circles around each vertex, which eventually expand to a single looping curve, and then into ovals encircling the entire triangle.
https://en.wikipedia.org/wiki/Cassini_oval#Generalizations
https://en.wikipedia.org/wiki/Polynomial_lemniscate#Erd%C5%9...