Several of Song Dong's works have conveyed a theme of the impermanence of change, highlighting the way that although a single person could effect a minor change it could only have a fleeting impact. In 1995 he began writing a daily diary on a flat piece of stone using clear water rather than ink, so that the letters would disappear as he wrote them. He subsequently visited
Tibet, where he photographed himself striking the
Lhasa River with an old-style
Chinese seal. The following year, he visited
Tiananmen Square in Beijing on a freezing New Year's Eve to create the piece
Breathing, showing himself lying face-down on the ground for 40 minutes until his breath had created a temporary sheet of ice on the pavement. He repeated the same thing on a frozen lake in a Beijing park that made no impression on the existing sheet of ice. As of 2012, it has so far been displayed in eight cities around the world. ==Artwork==