"There are weird occurrences on our planet that remain inexplicable just long enough to nurture all sorts of beliefs. Take for instance haunted houses. The reports of specters boomed in the Victorian era and the beginning of the 20th-century, a time when gas lamps were common. The theory goes that long-term exposure to substances emitted from gas lamps, such as carbon monoxide, could have stimulated some people to experience hallucinations or hear a bump in the night. Some knowledge of optics and how our atmosphere functions can help us explain a few more otherworldly experiences ..." (read more)