Fringe science refers to scientific ideas and theories that exist outside the mainstream scientific consensus. These concepts often lack rigorous testing and validation, making them controversial among scientists. Examples include topics like UFOs, psychic phenomena, and alternative medicine. While some fringe theories may spark interest or curiosity, they often do not adhere to established scientific methods. Despite their unconventional nature, fringe science can sometimes lead to new questions and explorations. Occasionally, ideas once considered fringe may gain traction and be studied more seriously, as seen with certain aspects of quantum physics or astrobiology. However, most remain on the periphery of accepted science.