Cosmology
PIRA classification 8C
8C10. Models of the Universe
PIRA # 
Demonstration Name 
Abstract 
8C10.05 
Cosmological Models 
A discussion of Red Shift, unbound universe, and other factors, and how they are applied to comological models. See The Physics Teacher  TPT 18(9), 639 
8C10.10 
The Big Bang 
The Big Bang and chirality of the universe. See The Physics Teacher  TPT 38(9), 564 
8C10.20 
Cosmic Microwave Background 
The study of anisotropies in the CMB. See American Journal of Physics  AJP 70(2), 106 
8C10.25 
Steady State, Expanding, or Contracting Universe 
The general Doppler formula in a nonstatic universe is derived. See American Journal of Physics  AJP 45(7), 642 
8C10.25 
Steady State, Expanding, or Contracting Universe 
A look at the question " Is the universe open or closed"? See The Physics Teacher  TPT 16(3), 137 
8C10.30 
Expanding Universe 
Pull a rubber hose threaded through five large styrofoam balls. See [ http://groups.physics.umn.edu/demo/old_page/astronomy.html University of Minnesota Handbook  8C10.10] 
8C10.30 
Expanding Universe 
Pull on a rubber rope with "galaxies" attached. See American Journal of Physics  AJP 50(6),571 
8C10.30 
Expanding Universe 
Using a strip of latex to model how long a light pulse would take to travel from one galaxy to another in an expanding universe. See American Journal of Physics  AJP 69(2), 125 
8C10.30 
Expanding Universe 
Use transparencies of a sample universe on the overhead to show center of expansion in an expanding universe. See The Physics Teacher  TPT 29(2), 103 
8C10.35 
Inflating Balloon 
A balloon with galaxies drawn on is blown up with compressed air. See [ http://groups.physics.umn.edu/demo/old_page/astronomy.html University of Minnesota Handbook  8C10.15] 
8C10.37 
Expanding Universe on a White Board 

8C10.39 
Expanding Universe 
Are we able to use experimantal evidence to calculate the total vector momentum of our expanding universe. Is it zero? See The Physics Teacher  TPT 20(9), 617 
8C10.40 
Bubble Universe 
Use a straw to blow bubbles in liquid soap. See [ http://groups.physics.umn.edu/demo/old_page/astronomy.html University of Minnesota Handbook  8C10.20] 
8C10.50 
Galaxy Model 
Show a 16" diameter galaxy model. See [ http://groups.physics.umn.edu/demo/old_page/astronomy.html University of Minnesota Handbook  8C10.30] 
8C10.55 
View of Galactic Center 

8C10.60 
Spiral Galaxies 

8C10.70 
Radio Galaxies 

8C10.80 
One Million Galaxies 
A poster showing 1 million galaxies taken at radio wavelengths. 
8C20. Gravitational Effects
PIRA # 
Demonstration Name 
Abstract 
8C20.10 
Klein Bottle 
A Klein bottle has been made from a 20 L flask. See [ http://groups.physics.umn.edu/demo/old_page/astronomy.html University of Minnesota Handbook  8C10.40] 
8C20.20 
Moebius Strip 
A strip of aluminum about six inches wide and six feet long is made into a Moebius strip. See [ http://groups.physics.umn.edu/demo/old_page/astronomy.html University of Minnesota Handbook  8C10.45] 
8C20.30 
Saddle Shape 
A ball is not stable when placed on a saddle shape, but surprisingly does become stable if the saddle shape is rotated. See American Journal of Physics  AJP 63(2), 186 
8C20.30 
Saddle Shape 
A butternut squash provides a negative space over small distances. At large distances the space becomes positive. A hubbard squash has a positive space. See The Physics Teacher  TPT 15(5), 298 
8C20.30 
Saddle Shape 
Two models of a negatively curved twodimensional space. One of fiberglass, and one made with strings. See The Physics Teacher  TPT 33(5), 286 
8C20.30 
Saddle Shape 
Two more examples. A hollowed out grapefruit is a positive space. Pringles potato chips are examples of negative space. See The Physics Teacher  TPT 16(1), 8 
8C20.35 
NonEuclidean Geometry 
A discussion of gravity touching on nonEuclidean geometry and the geometry of three dimensional space. See The Physics Teacher  TPT 22(9), 557 
8C20.35 
NonEuclidean Geometry 
A helpful discussion about space curvature and how to visualize it. See The Physics Teacher  TPT 29(3), 147 
8C20.35 
NonEuclidean Geometry 
Counting distant radio sources to determine if the overall curvature of space is positively curved, flat, or negatively curved. See The Physics Teacher  TPT 30(2), 92 
8C20.40 
Gravitational Lens 
A machined Plexiglas lens bends light like a black hole. See University of Minnesota Handbook  8C20.40 
8C20.40 
Gravitational Lenses 
A computer program to visualize gravitational lenses. See American Journal of Physics  AJP 69(2), 218 
8C20.40 
Gravitational Lens 
An equation is developed for constructing a Plexiglas lens. See American Journal of Physics  AJP 48(10),883 
8C20.40 
Directions for constructing a gravitational lens simulator from Plexiglas. Ref: Phys.Rev. 133, B835 (1964). See American Journal of Physics  AJP 37(1),103 

8C20.40 
Gravitational Lens 
A plastic lens that bends light the same way a black hole does. Theory and directions for construction of a lens. See American Journal of Physics  AJP 49(7),652 
8C20.40 
Gravitational Lens 
Viewing a fish in a fish tank. Refraction of light as the optical counterpart of a gravitational lens. See The Physics Teacher  TPT 25(7), 440 
8C20.40 
Gravitational Lens 
Constructions of a simple gravitational lens demonstration. See The Physics Teacher  TPT 34(9), 555 
8C20.42 
Gravitational Lens 
Henry Cavendish and Johann von Soldner calculated that light would be deflected by gravitational bodies long before Einstein. See American Journal of Physics  AJP 56(5), 413 
8C20.42 
Gravitational Lens 
How would the outer world look from an observer located in a gravitational lens. See American Journal of Physics  AJP 55(4), 336 
8C20.42 
Gravitational Lens 
The principle of equivalence and the deflection of light by the Sun. See American Journal of Physics  AJP 46(8), 801 
8C20.42 
Gravitational Lens 
The prediction and test of Einstein's 1916 prediction. See The Physics Teacher  TPT 38(9), 524 
8C20.42 
Gravitational Lens 
Additional comments on TPT 38(9), 524. See The Physics Teacher  TPT 39(4), 198 
8C20.43 
Gravitational Lens 
The black hole as a gravitational lens. See American Journal of Physics  AJP 55(5), 428 
8C20.45 
Galactic Lens 
A machined Plexiglas lens bends light like an extended mass distribution. See American Journal of Physics  AJP 51(9),860 
8C20.50 
Gravitational Waves 
Icebreaker activities to use when introducing the subject of gravitational waves. See The Physics Teacher  TPT 44(7), 416 
8C20.50 
Gravitational Waves 
About the new generation of gravitational wave detectors. See The Physics Teacher  TPT 44(7), 420 
8C20.50 
Gravitational Waves 
On the detection of gravitational waves. See The Physics Teacher  TPT 22(5), 282 
8C20.60 
Quasars 
The use of quasars in teaching introductory special relativity. See American Journal of Physics  AJP 55(3), 214 
8C20.60 
Quasars 
Quasars and superluminal velocities in astronomy. See The Physics Teacher  TPT 34(8), 496 
8C20.70 
Cosmic Strings 

8C20.80 
Dark Matter 
