Why do galaxies take a flat shape instead of sphere?

Why do galaxies take a flat shape instead of sphere?

The reason many galaxies are flat is because of the conservation of angular momentum. When objects revolve around the center of gravity, they have angular momentum.

Do galaxies expand with the universe?

However, the galaxies are not moving through space, they are moving in space, because space is also moving. The universe encompasses everything in existence, from the smallest atom to the largest galaxy; since forming some 13.7 billion years ago in the Big Bang, it has been expanding and may be infinite in its scope.

How are galaxies distributed?

Galaxies are not distributed randomly throughout the universe, but are grouped in graviationally bound clusters. The Milky Way is part of a poor cluster called the Local Group which contains about 50 galaxies including dwarf galaxies. Clusters are then grouped together in superclusters which contain dozens of clusters.

Why are galaxies discs and not spheres?

Galaxies are disc shaped because they are gas rich and dynamically young. Stars are also gas rich but they are dynamically old so they have had time to rid themselves of their discs.

Are galaxies equally distributed?

Galaxies are not evenly distributed. They are collected into large clusters of galaxies, with long “filaments” and “walls” of galaxies and clusters, and vast voids between them. However, on even larger scales the voids and walls do appear to be roughly evenly distributed, and about the same in every direction.

What are poor clusters of galaxies called?

These clusters are called poor or rich depending on how many galaxies they contain. Poor clusters are often called groups. The Milky Way is part of a poor cluster called the Local Group which contains about 50 galaxies including dwarf galaxies.

Does the cosmological principle apply to galaxies?

Explain the cosmological principle and summarize the evidence that it applies on the largest scales of the known universe In the preceding section, we emphasized the role of mergers in shaping the evolution of galaxies. In order to collide, galaxies must be fairly close together.

How many spiral galaxies are in the local group?

The three largest galaxies among the three dozen or so members of the Local Group are all spirals; the others are small irregular galaxies and dwarf ellipticals. A number of new members of the group have been found since this map was made. Small galaxy groups like ours are hard to notice at larger distances.