ringobob t1_isjmurd wrote on October 16, 2022 at 2:20 PM

Reply to comment by apollyon0810 in TIL: Sperms were thought to move by wiggling their tails side-to-side, like eels, for 350 years. But research shows that they roll as they move forward like a spinning top. by vect77

We see a mostly 2D image that is difficult to discern side to side movement on a plane vs a more complicated movement in 3d space that, when seen from above, looks like side to side movement on a plane.