 The end of the 19th century was a great time to be physicist. In 1893, Victor Schumann discovered vacuum ultraviolet radiation. In 1895, Wilhelm Röntgen discovered x-rays. In 1896, Henry Bacarell discovered radioactivity. And in 1897, J.J. Thompson discovered electrons, showing that they were the main constituents of cathode rays. Four major new phenomena were discovered within a decade, and this created the expectation that more were just around the corner. Then comes Professor of Physics at the University of Nancy in France, Prosper René Blondlot. Professor Blondlot, like many of the physicists of his day, was studying electromagnetic radiation. Blondlot was a well-respected member of the scientific community. He was one of the eight physicists who were corresponding members of the French Academy of Sciences, and was awarded the Academy's highest prize, the Gaston-Planter Prize in 1893 and the La Casse Prize in 1899 for his work on electromagnetism. His attempts to study the speed of electromagnetic radiation were commended by Nobel Lords J.J. Thompson and Henry Poncar, who had been nominated and astounding 54 times for the Nobel Prize between 1904 and 1912, since he could be nominated multiple times in the same year. In essence, Blondlot was a highly respected physicist at the forefront of his field. After the discovery of x-rays in 1895, Blondlot began investigating whether those x-rays behaved more like particles or as electromagnetic waves. This was still three decades before Einstein's wave particle duality theory became widely accepted among scientists. In 1903, while trying to polarize x-rays, Blondlot discovered a new form of electromagnetic radiation. He had received changes in the brightness of an electric spark placed in an x-ray beam, which he photographed, and he later attributed this change in brightness to a novel form of radiation, naming it N-rays for the University of Nancy. Blondlot was not alone in his discovery. After publication of his findings, more than 120 other scientists and more than 300 publications reported the ability to detect N-rays emanating from most substances, even the human body. Most researchers of the subject at this time detected the change in light by staring at a dim phosphorescent surface. A phosphorescent surface is one that emits visible light after being struck by radiation. Two other prominent scientists, with names I'm not going to try to pronounce, even claim the discovery as their own, forcing the French Academy of Sciences to step in and decide who truly discovered it first. The only problem? N-rays weren't and aren't real. The discovery excited international interests and many physicists tried to recreate the results. However, the notable physicists Lord Kelvin, William Crookes, Otto Lumer, and Henrik Rubens all failed to do so. After failing to reproduce the experiment, Robert W. Wood, an American physicist who was a pioneer in the field of infrared and ultraviolet photography and had gained a reputation as a popular debunker of nonsense during the period, was invited by the British journal Nature to travel to Blondlot's laboratory in France to investigate further. So Woods traveled to Nancy, France to observe the experiment in action. Being familiar with the workings of the experiment and wanting to test its validity, Woods secretly removed an essential prism from the experimental apparatus. Without it, the experiment should have failed, but curiously enough it didn't, and Blondlot and his team still said they observed N-rays. Further testing his theory, Woods replaced the metal plate that was supposed to be giving off N-rays with an inert piece of wood, yet the N-rays were still detected. Upon his return to America, Woods published his findings in the journal Nature, suggesting that N-rays weren't real, and that the scientists involved were recording data that matched their expectations. There's reason to believe that Blondlot in particular was misled by his laboratory assistant, who personally confirmed all of his observations. Kind of like a yes-man. No blind experiments had ever been conducted, and Blondlot's team only ever tried to prove the existence of N-rays rather than disprove their existence like Woods had done and like all scientists should do. Within a year, no one outside of Nancy believed in N-rays, although it's reported that Blondlot so believed in them in 1926 shortly before his death. It turns out, nearly identical properties of an equally unknown form of radiation were reported more than 50 years prior by multiple physicists. In fact, some of the scientists on Blondlot's team were even aware of those previous findings, although it's not clear whether Blondlot himself was personally aware of it. Today, the N-ray debacle is used as a cautionary tale among scientists on the dangers of errors introduced by experimenter bias. Not knowingly lying, sometimes expecting to see something can trick your mind into actually seeing it, especially when you're relying on qualitative analysis rather than quantitative data. I hope you enjoyed this episode of Everything Science, and if you made it this far in the video, you probably did. If you did, make sure to like and subscribe so you stay up to date on all our future episodes, and if you have an idea for something you want us to cover in the future, be sure to leave that in the comment section down below. And remember, there's always more to learn.