1. Fritz Zwicky and Dark Matter Wes Donehower

2. The “Missing Mass” Problem In 1933, Zwicky was studying galaxies and he estimated their total mass by measuring their brightness Then, he used a different method of measuring the mass, and came up with a number 400x his estimate Nobody did anything about it

3. Dark Matter When scientists began to realize that large amounts of hidden mass would explain a lot of their findings, they began to search for “Dark Matter”

4. Dark Matter Dark matter cannot be seen or felt; Its existence is implied Could be subatomic particles lighter than an electron or black holes millions of time more massive than the Sun.

5. MACHO’s and WIMP’s WIMP (Weakly Interacting Massive Particles) Smaller than atoms MACHO (Massive Astrophysical Compact Halo Objects) Black Holes Brown Dwarfs

6. Dark Matter It is believed that Dark Matter could make up 90% of our Universe Some scientist are skeptical of WIMP’s existence, but it seems unlikely that MACHO’s could make up 90% of our Universe The discovery of Dark Matter would affect our place in the Universe