From Wikipedia:

Masaru Emoto

Masaru Emoto was a Japanese businessman, author and pseudo-scientist who claimed that human consciousness could affect the molecular structure of water. His 2004 book The Hidden Messages in Water was a New York Times best seller. His conjecture evolved over the years, and his early work revolved around pseudo-scientific hypotheses that water could react to positive thoughts and words and that polluted water could be cleaned through prayer and positive... Read More