N-rays are a newly discovered type of radiation emitted by many substances, particularly metals and the human body, found by French physicist René Blondlot in 1903.
N-rays were claimed by Blondlot but were never independently replicated. American physicist Robert Wood visited Blondlot's lab and conducted blind tests, revealing that the 'detection' of N-rays was due to observer bias and expectation rather than any real phenomenon. The N-ray episode became a classic cautionary tale about the importance of blind experimental controls and peer verification in science.