Talk about solitary confinement – a French artist has entombed himself inside a 12-tonne rock with space just big enough for him to sit up in, and plans to stick it out for a week.” I am traveling in this rock without moving, like an astronaut,” Abraham Poincheval, 44, said through a crack in the limestone boulder.Known for his unusual performances, he made headlines when the two halves of the rock… Talk about solitary confinement – a French artist has entombed himself inside a 12-tonne rock with space just big enough for him to sit up in, and plans to stick it out for a week.