Walter Isidor Siegmeister (October 5 or 6, 1903 – September 10, 1965),[1][2][3][4][5] later known as Raymond W. Bernard,[6] was an early 20th-century American alternative health advocate and esoteric writer,[6] who formed part of the alternative reality subculture.[5] He is credited with the merger of the Hollow Earth theory and religious beliefs about UFOs.[6]