Dark matter is currently estimated to make up approximately 90% of the universe's total mass (Rubin 73).  There presently exist two distinct theoretical candidates to explain the presence of dark matter: massive dark bodies, ordinary matter that does not emit light, or minute particles present throughout the universe.  Massive bodies could be brown dwarfs, black holes, neutron stars or gasses and dust (Rubin 106).  The minute particle most likely to account for dark matter is the neutrino, which is said to be nearly weightless and extremely abundant (Hawley 389-393).

    Long ago, Aristotle held the belief that an invisible force propelled objects through space (Hawley 26).  This belief held sway until it was gradually replaced with the more modern notion of inertia. Concepts of invisible forces have played important roles throughout the history of scientific understanding of the cosmos.  Our plan is to study Greek notions of invisible force that affects observable reality.

    For the observation aspect of this project, we will select a galaxy to observe through the 8" Orion telescope from Lab Stores and determine the basic shape of that galaxy.  We will then gather data from scientific sources on the velocities of rotating bodies within that galaxy relative to their distance from the apparent center.  This data will be applied to Kepler's third law, p²=r³ where p is the length of time a complete orbit takes to make around its foci and r is the size of the semi-major axis of the orbit.  We will then compare this data with similar data on our own solar system.  The presence of extra gravitational force, in the form of dark matter, can be confirmed or denied by using Kepler's third law to predict the periods of orbit relative to the semi-major axis.