It is the stage of the universe, the space between the stars,   it is the
Canvas of the Cosmos
Vacuum is the prevalent state of the universe.

 Just as Nature paints atoms into galaxies upon the face of the deep space,
humans have created things from light bulbs to lasers, mirrors to
microelectronics and food substances to pharmaceuticals using vacuum

  Here is a brief history of the discovery of vacuum.

 You can find a better and more detailed history of vacuum science by checking
out  Society of Vacuum coaters

 To quote Genesis:  "In the beginning there was darkness without form and void".
  That set the stage for the universe. Some claim that there was a great paint explosion and then there
 became light and stuff.

 Billions of years later, in the 17th century, came the realization that man could use vacuum too.
 Theories about the validity of vacuum were debated amongst the ancient
Greek. Roman of  420 BC ( Democritus, Aristotle et al. ) and later of medieval natural
philosophers up to the 17th  and early 18 th. Century ( Descartes, Boyle et al. ).

 Galileo was one person who started doing actual experiments like trying to draw water
up a straw that was taller than 30 feet. He noticed that, no matter what he did from the top,
he could not get the water to be "sucked" up any higher.  Later, others decided to place the
pump at the bottom of the well, that permitted the water to be pushed higher than the 30
foot height limit.

 So what good is a vacuum?
 The first use of vacuum was discovered by Torricelli in 1644, is the classical barometer 
that is now used for part of weather forecasting.

 Why use a vacuum?

 (1)  Vacuum is room for stuff.  It is used to provide a physically clear space for things
(and radiation, such as light) to move through without being hindered.

 In Nature

  The space between the sun and the earth is a vacuum.  Notice that the appearance of the sun light is
brighter during the mid-day than sunrise or sunset.  The sunlight passes through more air during
sunrise and sunset.  The thicker air in the lower atmosphere scatters the blue light of the sun light
back into space thus giving the sun an orangish cast.
 The breathable atmosphere of the earth is only a 1000th of the earth's diameter.
That is on the scale of a sheet of writing paper compared to the diameter of a basket ball.
  On that scale the sun would be the size of a 10 story building that is about 5
miles away.  Light could not get from the sun to the earth if there was atmospheric-pressure air in
between; the resistance to motion would be like trying to toss that basketball through thick mud.

 In man made works

  An old, tube-type television used a cathode ray tube as a display.  This uses what is called an electron
beam or  cathode ray  streaming from the small rear end towards the screen or front face of the fat set.
 This electric beam causes the phosphor on the inside surface the glass face to glow.  The beam is scanned and its intensity is varied to produce a picture. Electron beams are hindered by air.
  Even  a millionth of an atmosphere inside would scatter the beam, cause a very fuzzy,
unfocusable picture or simply not work.

 Currently made LCD and other thin flat panel computer and television displays are also made in
vacuum environments like those found within the tubes of old TVs.

 Besides providing an unobstructed space, vacuum is used to:

 (2)  Reduce or prevent undesired chemical reactions of sensitive materials with the air.

 (3)  Evaporation at lower temperatures at reduced pressures, thus reducing or
       avoiding the decomposition in the distillation or condensation of heat sensitive materials.

 (4)  Insulate by preventing heat from being carried away from heated objects (or to cooled
       objects) by air convection.


 This is a drawing of Edison with his team and friends, 
together making one of the first incandescent light bulbs 
in October 19, 1879. 
 <The pump, the tall thing to the left, was  invented 
by Sprengel in 1865. Edison had to beg for the use of it
until he could obtain one of his own.
 The newly discovered vacuum pumps were primarily used for scientific research in academic
 One of the first mass consumer products of the then-new vacuum industry was the light bulb.

 A lot went on between that time and now, which is beyond the scope of this site.

 Today, vacuum is used in a wide variety of research projects ranging from chemical distillation to
sugar refinery and food drying, microprocessor manufacturing. Giant beam  machines are used for everything from matter investigation, materials processing to cancer treatment.

  The theory of air pumps designed for vacuum service
  A-shopping we will go.  In the past, we had to travel 
to uncertain surplus stores and other used equipment dealers. 
  Now we can enjoy much more repeatable projects free from 
the influence of "cool weird stuff."  These parts are available 
from easily found outlets in or about most towns.
 Make an actual air pump designed for vacuum 
service using only simple hand tools.  
 This design avoids reliance on expensive and hard to access  machine shops.
 Make a small replica of the first 
electric lamp. This one gives off 
safe, long-wave ultraviolet light. 

 The illustration here is a simplified simulation of a 
rarefied nitrogen  (air) discharge.


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