We believe that a sofa is a solid object upon which one can settle down just as one pleases and be active in contemplative stillness. But we're making a big mistake there. De facto, it is an unimaginable system that consists of 99.9999... percent nothing and an infinitesimal trace of pollution – matter, which for its part is formed by ghostly material waves that retreat from every attempt to access them. To be precise, the part of a sofa mentioned is only a hard shadow from the space above, a local irregularity of space-time geometry. Still, you can sit on it.