Which factor is essential to the initial formation of galaxies, for either of the theories describing galaxy evolution?(1 point) Responses Small lumps of material merge into larger clumps. Small lumps of material merge into larger clumps. Massive gas and dust clouds collapse. Massive gas and dust clouds collapse. The force of orbiting stars generates collisions. The force of orbiting stars generates collisions. Gravity acts on existing material, shaping it into a new form. Gravity acts on existing material, shaping it into a new form.
Massive gas and dust clouds collapse.
For both theories describing galaxy evolution, the essential factor to the initial formation of galaxies is: "Massive gas and dust clouds collapse."
The correct answer to the question is "Massive gas and dust clouds collapse."
To understand why this factor is essential to the initial formation of galaxies, we need to explain the process of galaxy formation as described by the leading theories. There are two main theories that describe galaxy evolution: the hierarchical model and the monolithic collapse model.
In the hierarchical model, galaxies are thought to form through a bottom-up process, where small lumps of material merge into larger clumps. This process occurs over billions of years as gravity pulls these smaller structures together, eventually forming galaxies. However, this process is not specifically related to the initial formation of galaxies.
In contrast, the monolithic collapse model suggests that galaxies form from the collapse of massive gas and dust clouds. These clouds, composed of hydrogen, helium, and small amounts of other elements, are present in the early Universe. As gravity acts on these clouds, they start to contract and become denser, which leads to the formation of stars within them.
The collapse of these massive gas and dust clouds is considered essential to the initial formation of galaxies because it sets the stage for the subsequent processes that shape the galaxy. As the gas and dust cloud collapses, it forms a rotating disk. Within this rotating disk, the force of orbiting stars can generate collisions, leading to the formation of galactic structures like spiral arms and bulges. Additionally, gravity acts on the existing material, pulling it together and shaping it into a new form.
Thus, the collapse of massive gas and dust clouds is a critical factor in the beginning stages of galaxy formation according to the monolithic collapse model.