Modern physics are built on a foundation put in place by two scientific giants: Sir Isaac Newton and Albert Einstein. What might happen if their theories - especially regarding gravity - turned out to be wrong?

Most astrophysicists believe that galaxies are held together by a mysterious substance known only as "dark matter."  Nobody can see it, and nobody really knows for certain what it is, but it is the gravitational force exerted by this "dark matter" that keeps stars from flying off into the void of intergalactic space. According to Newtonian gravitational theory, stars, gas clouds and planets by themselves lack sufficient gravity to keep galaxies in one piece.

A competing theory, known as "Modified Newtonian Dynamics," or MOND, has been gaining ground. In short, it is a theory indicating that galaxies stay together, not because of "dark matter," but because gravity does not weaken with distance as much as Newtonian physics would predict. After going through many revisions over the course of the last twenty years, scientists in Israel  have concluded that the curvature of space/time causes gravity to behave differently than it otherwise might.

This new theory has not convinced all scientists, however, who are still looking for ways to prove the existence of "dark matter." Currently, some universities in the U.S. are running the Cryogenic Dark Matter Search II, in which silicon crystals are monitored for small vibrations set off by collision with "dark matter."

The research and debate will likely go on for decades...after which we may very well discover that MOND and dark matter really DON'T matter.