namespace blobs {
constexpr double PI = 3.141592653589793238462643383279502884;
-constexpr double PI_0p25 = PI * 0.25;
-constexpr double PI_0p5 = PI * 0.5;
-constexpr double PI_1p5 = PI * 1.5;
-constexpr double PI_2p0 = PI * 2.0;
-
constexpr double PI_inv = 1.0 / PI;
-constexpr double PI_0p5_inv = 1.0 / PI_0p5;
/// gravitational constant
constexpr double G = 6.674e-11; // m³kg¯¹s¯²