1920s

  • Electric Automatic Traffic Signal

    Electric Automatic Traffic Signal
    The first electric automatic traffic signal in 1923; the design of the first three color system (red/yellow/green) and t-shaped bar was patented and sold to General Electric. With the expansion of personal vehicles, electric lights also grew.
  • First Polaroid Camera

    First Polaroid Camera
    Samuel Shlafrock; The first version of an instant camera was created at this time, and made available shortly after for individuals to purchase. This influenced society's desire to take and see pictures without delay.
  • Liquid Fuel Rockets

    Liquid Fuel Rockets
    Robert Hutchings Goddard ; Research during the World War led to advancements in using liquid fuel for rockets, which contributed to the advancement of further rocket and astronautic science.
  • First semiconductor transistor

    First semiconductor transistor
    First patent for the semiconductor transistor; responsible for regulating voltage/current, transistors are responsible for current day advances in microchips and CPUs
  • Image of Dissector

    Image of Dissector
    First Patent by Philo Farnsworth; The invention of the Image Dissector was considered the first all-electronic image pickup device. This device and invention led to the first all-electronic television.