RT 100 - Midterms.pdf

RADIOLOGY: A HISTORIC PERSPECTIVE First Century AD: Archimedes - explained the reaction of solids when they are placed in liquids. Democritus - described materials as benign composed of ultimate particles Thales - discovered some of the effects of electricity Pioneers...

RADIOLOGY: A HISTORIC PERSPECTIVE First Century AD: Archimedes - explained the reaction of solids when they are placed in liquids. Democritus - described materials as benign composed of ultimate particles Thales - discovered some of the effects of electricity Pioneers of Radiology: Three aspect of physical science that helped pave the way for discovery of x-rays: Electricity Vacuum Tubes Image-recording Materials (i.e, the photographic recording techniques) Evangelista Torricelli ↪ produced the first recognized vacuum ↪ invented barometer in 1643 Otto van Guericke ↪ invented an air pump that was capable of removing air from a vessel or tube in 1646 Robert Boyle - repeated Otto van Guericke’s experiment (air pump) in 1659 Herman Sprengel ↪ same with Robert’s but in the 1865 ↪ invented a mercury vacuum pump, now know as the Sprengel Pump Sprengel Pump - sucked the air out of a light bulb and preserved the filament. Robert & Herman’s techniques improved the amount of evacuation, making better vacuum tubes available for further experimentation by other scientists. 17th Century: Experiments with electricity Electroscope ↪ an early scientific instrument that is used to detect the presence and magnitude of electric charge on a body. ↪ the very first electrical measuring instrument ↪ forerunner of the x-ray tube. William Gilbert (England) (Father of Electricity) ↪ one of the first to extensively study electricity and magnetism. ↪ noted for inventing a primitive electroscope. ↪ around 1600 and it was a pivoted needle called the “versorium” ↪ Invented the term “electricity” ; laid the foundation for discoveries around electricity ↪ He discovered laws of attraction and repulsion between magnets; published findings in ‘DE MAGNETE’ (1600) Robert Boyle (Irish Philosopher, Chemist, and Physicist) ↪ discovered that electric force could be transmitted through a vacuum ↪ observed attraction and repulsion ↪ his experiment with electricity earned him a place among the serious investigators. Isaac Newton ↪ built and improved the static generator. ↪ “Electrostatic Generator” Charles du Fay ↪ working with glass, silk, and paper, he distinguished two different kinds of electricity. (positive - vitreous and negative - resinous) Abbe-Jean-Antonie Nollet ↪ made a significant improvement in the electroscope, a vessel for discharging electricity under vacuum conditions. Benjamin Franklin ↪ conducted many electrical experiments. William Watson ↪ demonstrated a current of electricity by transmitting electricity from a Leyden jar through wires and a vacuum tube. William Morgan (British Physician, Physicist, and Statistician) ↪ presented a paper to the Royal Society of London in which he described the effect of passing electrical currents through a partially evacuated glass tube. ↪ He describes how a glow appears, and today this glow is believed to have been produced by x-rays. ↪ when a tube cracked and some air leaked in, the amount of air in the tube determined the coloration, like the lightbulb at our house ↪ example of discoloration process or how something discolors Michael Faraday ↪ induced an electric current by moving a magnet in and out of a coil. ↪ this experiment involved the concept of electromagnetic induction, which led to the production of better generators and transformers and high voltages for use in evacuated tubes. ↪ credited for the discovery of electromagnetic induction. Heinrich Daniel Ruhmkorff (Paris) ↪ made the most significant improvement on induction coils. Johann Wilhelm Hittorf ↪ conducted several experiments with cathode rays, which are streams of electrons emitted from the surface of a cathode. William Crookes ↪ furthered the study of cathode rays and demonstrated the matter was emitted from the cathode with enough energy to rotate a wheel placed within a tube. ↪ He also further repeat and developed Hittorf’s work Philipp Lenard ↪ furthered the investigation of the cathode rays. ↪ found that cathode rays could penetrate thin metal and would project a few centimeters into the air. ↪ determine the energies of cathode rays by measuring the amount of penetration. ↪ also studied the deflection of rays as a result of magnetic fields. William Goodspeed (A.W. Goosdpeed) ↪ produced a radiograph in 1890 (radiograph of coins with William Jennings)) ↪ his achievement was recognized only in retrospect Wilhelm Conrad Roentgen ↪ discovered x-ray in November 8, 1895 Johann Heinrich Schulze ↪ produces the first photographic copy of written materials in 1727 Richard Leach Maddox ↪ In 1871, he produced a film with a gelatin silver bromide emulsion that later became the basic components for film. George Eastman ↪ In 1884, he produced and patented roll paper film ↪ Founder of Kodak The image-recording materials were very important to the investigators of the cathode rays. With its significant improvement and the improvement in the cathode ray tube, the basis for twentieth century radiography was established.