Ajit Pai @AjitPai
OTD in 1895, Wilhelm Roentgen did an experiment in which he passed current through glass tubes to study emerging cathode rays. When he covered tubes with black cardboard, he saw that invisible rays illuminated a screen 9 feet away. He'd discovered x-rays. https://t.co/invQcdcpX4 https://t.co/CmRYmTyR4C — PolitiTweet.org
