Discovery of  X-rays

X-ray was discovered by Dr. Wilhelm Conrad Rontgen in 1895 when he was conducting light experiments with a high voltage tube (Crookes Tube).

Dr. Rontgen hypothesized the glowing fluorescent screen coated with barium platinocyanide lying under the tube on the table was caused by an unknown type of radiation (energy) generated by the high voltage tube which he later named X-radiation or X-rays . After the mathematical term "X" denotes something "unknown".

The first X-ray image Dr. Rontgen took was his wife Bertha's hand with her wedding ring clearly visible. This is one of the most famous scientific images in recent history.