Zwicky's contribution to science
Fritz Zwicky was an astronomer at the California Institute of Technology (Caltech). This is where he stumbled across the gravitational effects of dark matter in early 1930, while studying how the galaxies move within a Coma Cluster. A Coma Cluster consists of around 1,000 galaxies which are spread across two degrees in the sky, and four times the size of our Sun and the Moon seen from Earth. The Gravity binds the galaxies together into a cluster. This is known as a galaxy cluster. The galaxies do not orbit any particular heavy object such as a gravitational bound between the planets and our Sun, meaning that objects in this Cluster carry out more complicated orbits.
Zwicky then pursued on to carry out his discovery, persuading Caltech to build an 18-inch Schmidt telescope that could capture a large number of galaxies in a single wide-angle photograph. He used this instrument to create a diagram of all of the galaxies in the cluster. By doing this Zwicky used measurements of the Doppler shift of their spectra to determine their velocities, he then applied the virial theorem. This was a straightforward application of classical mechanics, the virial theorem uses the velocity of the orbiting objects to the amount of gravitational force that is acting on them. Isaac Newton's theory helped Zwicky finish off his research as Newtons theory tells us that the gravitational fore is proportional to the masses of the objects involved, so Zwicky was then able to calculate the total mass of the Coma Cluster from his measured galactic velocities.
Zwicky then pursued on to carry out his discovery, persuading Caltech to build an 18-inch Schmidt telescope that could capture a large number of galaxies in a single wide-angle photograph. He used this instrument to create a diagram of all of the galaxies in the cluster. By doing this Zwicky used measurements of the Doppler shift of their spectra to determine their velocities, he then applied the virial theorem. This was a straightforward application of classical mechanics, the virial theorem uses the velocity of the orbiting objects to the amount of gravitational force that is acting on them. Isaac Newton's theory helped Zwicky finish off his research as Newtons theory tells us that the gravitational fore is proportional to the masses of the objects involved, so Zwicky was then able to calculate the total mass of the Coma Cluster from his measured galactic velocities.