Scientists are searching for Wimps. Weakly interacting massive particles are a particle that we think is sub-atomic, accounts for 85% of matter in the universe, and we just can’t find the stuff.
The most obvious clues of dark matter began coming in as soon as we had telescopes capable of observing remote galaxies. In the 1920’s astronomers were fascinated by the Milky Way and the stars in the night sky, but indications arose that there were more galaxies than just the Milky Way.
With less powerful telescopes, we looked at the night sky and believed everything was a star. We knew that the Milky Way was a dense galaxy of stars, but it was the more powerful telescopes that showed us that some things that we thought were stars were other galaxies.
Lord Kelvin advanced the theory that objects unseen were subjecting gravitational pull within the Milky Way in a talk given in 1884. He speculated that a large percentage of star bodies were dark in the Milky Way. In 1906 Frenchman Henri Poincare advanced the notion of matiere obscure, or dark matter.
In the 1920’s Dutch astronomers Kapleyn and Oort further advanced the theory of Dark Matter and Fritz Zwicky in 1933 was working at the California Institute of Technology and had access to the Mount Wilson Observatory and the Palomar Observatory. He made records of the rotation of galaxies other than the Milky Way and advanced the idea that the rotation of galaxies would cause them to fly apart without Dark Matter.