(Courtesy Oregon Timber Trail) 1  Since 1992, hikers have been able to traverse Oregon north to south using the Pacific Crest Trail, which traces the Cascades from the Bridge of the Gods to the California state line. This summer, you can finally bike across the state, from Hood River to the mines of Modoc County, Calif.
Definition: A delta wave is a type of high amplitude brain wave found in humans. Delta waves have a frequency from one to four hertz and are measured using an electroencephalogram (EEG). These brain waves are thought to emerge from the thalamus and are generally associated with slow-wave sleep (during stages three and four of the stages of sleep.
Definitions for mechanical wave. Mechanical wave. A mechanical wave is a wave that propagates as an oscillation of matter, and therefore transfers energy through a medium. While waves can move over long distances, the movement of the medium of transmissionâthe materialâis limited.