Early Vacuum Technology and Electricity

Early Vacuum Technology and Electricity

• Evangelista Torricelli (1643): Created a sustained vacuum and developed the principle of the barometer.
• Otto von Guericke (1649): Invented the spool vacuum air pump and the first electrostatic generator.
• Robert Boyle & Hermann Sprengel (1865): Invented the mercury vacuum pump (Sprengel pump), crucial for creating vacuums in light bulbs.

Early Experiments with Electricity and Magnetism

• William Gilbert (1600): Studied electricity and magnetism; invented the versorium, an early electroscope; discovered the law of attraction and repulsion between magnets. His work, 'De Magnete', influenced Galileo's heliocentric theory.
• Robert Boyle: Showed that electric force could be transmitted through a vacuum.
• Charles du Fay (1733): Discovered two types of electricity, "vitreous" and "resinous".
• Abbé Jean-Antoine Nollet: Improved the electroscope and developed a method for discharging electricity under vacuum conditions.
• William Watson: Demonstrated electrical current transmission through wires and a vacuum tube using a Leyden Jar.
• William Morgan: First documented "invisible light" (X-rays) produced by a current passing through a partly evacuated tube. (1785)

Electromagnetic Induction and Cathode Rays

• Michael Faraday (August 29, 1831): Contributed significantly to electromagnetism and electrochemistry; discovered electromagnetic induction.
• Heinrich Daniel Ruhmkorff: Made significant improvements to induction coils.
• Johann Wilhelm Hittorf (1869): Experimented with cathode rays, noting that different gases and pressures produced different colored glows; ascertained that these glows were streams of electrons.
• William Crookes: Demonstrated that matter emitted from the cathode had enough energy to rotate a wheel; showed cathode rays travel in straight lines, and produce phosphorescence and heat.
• Philipp Lenard: Showed that cathode rays could pass through thin metal leaves and into open air.

Early X-ray Discoveries and Photography

• First shadow picture (accidentally taken): February 22, 1890, University of Pennsylvania.
• A.W. Goodspeed & William Jennings (1896): Reproduced an X-ray image of coins, duplicating an accidental image from 1890.
• Johann Heinrich Schulze (around 1717): Produced the first photographic copy of written material.
• Richard Leach Maddox: A significant contributor to photographic processes but not directly connected to X-ray discovery in this text.