If you do not have any Lego at hand just fire up your 3D printer to make a tensegrity physics toy or a floating table.
It seems that tensegrity structures are trending online, possibly due to the seemingly impossible nature of their construction. The strings appear to levitate without any sound reason, but if you ...
If you have ropes and wood - you can build floating tensegrity chair based on tension! It was pretty difficult project, but ...