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Notes on video lecture:
Image Formation
Choose from these words to fill the blanks below:
Fermat, full, sheet, lens, bottom, upside, refracting, shaped, circumference, 40, sees, pinhole, flat, focus, expose, designed, curved, photons, point, nothing, inevitable
the image that we produce inside of our view camera is              down
takes a picture with lens
a clear picture
takes a picture without the lens
"all you see is more or less uniform               "
why does this happen?
light spreads out from a            in all directions
we assume that but there is proof of this
you point out an object to a friend and your friend acknowledges that he          it, too
light that enters your eyes is a different set of                than are entering your friend's eyes
why don't we get a picture of an object if we simply              film in its present
you can't have an image without some way to            light
the reason is that photons from the light source are hitting the          area of the exposed film
but if you have a            of film, an object emitting light, and between then a               
then only the light that goes through he pinhole will hit the film, but as it goes through hole, the light from the top of the object hits the              of the film and vice versa
adding a lens to the pinhole will focus the light in various ways, but it remains                      that the image created on the film is upside-down in relation to the object which is emitting light
you can also use a              mirror
there are differences between the images that we get with curved mirrors
there are limitations that we currently have with lenses
or a          can be used at the point where the pinhole is
a lens is very thin at the edges
however, it is very hard and expensive to make a large piece of class which is thin around its                           
this is one of the reasons why                      telescopes which use lenses instead of mirrors are limited
the largest refracting telescope is only about      inches in diameter
the lens is              as it is so that the light has a way to "know where to go" to create the image
the principle of least time, by Pierre             
part of the way our modern lenses of cameras are                  today
recently people have begun to think about the possibility of making a          lens
the way you do that is a very strange idea that has to do with the way light bends when it goes through an object
but it would enable engineers to make larger telescopes

People:

Pierre de Fermat (1601-1665)
Amateur mathematician who developed the principle that the path taken between two points by a ray of light is the path that can be traversed in the least time
  • Fermat's principle
  • responsible also for its derived principle that a light ray incident upon a reflective surface will be reflected at an angle equal to the incident angle
  • both principles important in the manufacture of lenses for telescopes and cameras
  • given credit for early developments that led to infinitesimal calculus
  • together with René Descartes, Fermat was one of the two leading mathematicians of the first half of the 17th century
  • Isaac Newton wrote that his own early ideas about calculus came directly from Fermat's way of drawing tangents
  • officially only an amateur mathematician, Fermat worked as a lawyer at the Parliament of Toulouse, France

Spelling Corrections:

circumfrencecircumference

Ideas and Concepts:

Why we don't get a picture of an object if we simply expose film in the presence of an object and why pictures on exposed film are upside-down in relation to the object, via this afternoon's Analyzing the Universe class:

"You can't have an image without some way to focus light. The reason for this is that every part of the object being photographed sends out photons in all directions, and these photons from every part of the object will hit every part of the film and thus create on the film a more or less uniform fuzz.

However, if you insert a panel with a pinhole of light between the sheet of film and the object emitting light, then only the light that goes through he pinhole will hit the film, but as it goes through the hole, the light from the top of the object hits the bottom of the film and vice versa.

Adding a lens to the pinhole will focus the light in various ways, but it remains inevitable that the image created on the film is upside-down in relation to the object which is emitting light."
The Nature of Images
Image Formation
Capturing Images of X-Ray Sources from Space