Holography requires temporally and spatially coherent light. They should be logically coherent and consistent with one another. The distinction lies in the coherent and unified nature of fantasy. By the 1970s the group developed into a more coherent and unified organisation. Coherent systems generally use optical heterodyne detection. It is at that this point that the epic stops being a coherent narrative. More clearly present, perhaps, than in a completely coherent work. West claimed that a more coherent and distinguishable definition for the stages is needed. A speckle pattern is produced by the mutual interference of a set of coherent wavefronts. It is perfectly coherent to all orders. This is the consequence of the fact that the system is internally coherent. Speckle also occurs if multiple parts of a coherent wave scatter from different centers. The game's early development was troubled due to a lack of coherent vision. This is accomplished through coherent states. Memories associated with trauma are typically explicit, coherent, and difficult to forget.