You have to watch this. In the artist's website, Jolan Van Der Wiel explains;
"The Gravity Stool thanks its unique shape to the cooperation between magnetic fields and the power of gravity. Departing from the idea that everything is influenced by gravitation, a force that has a strongly shaping effect, I intended to manipulate this natural phenomenon by exploiting its own power: magnetism. The positioning of the magnetic fields in the machine, opposing eachother, has largely determined the final shape of the Gravity Stool. It is the combination of the gravity tool and the two-component plastics, developed especially for this purpose, that enabled me to start a small but efficient chain of production. The products are characterized by the unpredictable organic shapes that are so typical of nature itself."