The Fruit of Samara

A maple seed falls in a characteristic helical motion; the shape of a helix; spiral.  

 Introduction 

 When I (Trent) was younger, I always loved playing with samara seeds. I would collect them up – careful not to damage them, and drop them from the highest place I could find. Noticing as they topple for just a moment then, with an almost eerie certainty, "floop!" right into rhythm copter-ing gently on down... landing softly on the grass as I swiftly released the breath I'd been grasping onto. Phew! Relief. Softness. Stillness. Safety. Certainty. 

 

 Observation 

 It appears the " initial transition from rest to a steady gyration" occurs in three steps: #First  a tumble about the span-wise direction , followed by a tilt towards the vertical axis , #Second  leading to the gyration about the vertical axis and an opening of the cone angle before #Third  finally settling into a steady state descent towards Planet Earth . 

 There is Peace within that Patience.  There is Joy & Excitement, anticipating each samara's transition to its own personal fall, it's own transitional drama into the ground. 

 

 The Drama, that's It. 

 The Drama is that story being played out in "real-time", suspended within those critical moments of transition... trusting that yes even the most damaged/misshapen/puny/enormous/ugly seed's leading edge, does indeed, have the Life Source encoding necessary for what Life intends. 

 Inquiry 

 Q: How does Samara settle into its steady-state spiral descent toward Germination? 

 A crude analogy of a wind turbine suggests that the torque due to aerodynamic force would initiate the gyration of the seed. " A surprise came when we cut off much of the wing of a maple seed and found that the seed still gyrated about the vertical axis. This immediately suggests that the cause of the gyration has little to do with the steady-state aerodynamic torque. " " In fact, a seed with only a sliver of leading edge can still gyrate. " (However, if the aerodynamic force is completely absent, a seed would fall from rest like a rock in a vacuum.) 

 Conclusion 

 The 3 essential ingredients that lead to helical motion. 

 #First is the "asymmetric mass distribution" of the seed, with the centre of mass "far away from the centroid" of the seed. 

 #Second is the "aerodynamic damping that initiates a tilt" of the seed which eventually "evolves into a helical motion due to the rigid-body dynamics." 

 #Third is the "aerodynamic force in the steady state " that "balances the weight of the seed and the centrifugal force ." It appears it is " the subtle coupling between the initial aerodynamic torque & the rigid-body dynamics " that distinguishes this case from all the other autorotational mechanisms. It appears it is " the subtle coupling between the initial aerodynamic torque & the rigid-body dynamics " that distinguishes this case from all the other auto-rotational mechanisms. 

 We now listen as Samara discovers her steady-state descent towards Planet Earth...  Study source: https://dragonfly.tam.cornell.edu/publications/2012_nonlinearity_kapil.pdf