You are not going to believe this: there are thousands of papers and robotic toy products for spider-like robots and gadgets and even larger numbers of pundits and YET I was unable to find a fully solved simple spider with correct and complete physics.

There are many half-solved octopods but with neglected caveat: the spider’s frames keep it standing erect! No no no no … the actual challenge of this dynamical system is to model an Idel-mode, namely then the dynamical system is in an at-rest configuration.

For me the most important question in all physics is not something of the cosmos or atoms rather: How can a human child stand erect! Or even the adults!