Crookes tube

A Crookes tube is an early experimental device used to study electron behavior. It consists of a sealed glass tube with metal electrodes and a vacuum inside. When a high voltage is applied, electrons are emitted from a negative electrode (cathode) and travel through the vacuum toward a positive electrode (anode). This movement creates visible effects, like glowing or fluorescence on the tube’s walls, and helped scientists discover electrons and develop the fundamentals of electronics and vacuum physics. Crookes tubes laid the groundwork for modern televisions, CRT displays, and electron-based technologies.