Gravitational forces are super important when it comes to how galaxies are formed. They act like a glue, pulling big things in the universe together. In the very early universe, there were small changes in density that started this whole process. These little differences helped gravity pull matter into specific areas.

Density Changes:

• Right after the Big Bang, the universe was filled with hot stuff called plasma.
• As it spread out and cooled down, tiny changes in density popped up.
• Areas where there was slightly more stuff started pulling in other nearby matter stronger than before.

Gravitational Collapse:

• When matter began to clump together because of gravity, these areas started to collapse under their own weight.
• This is when protogalaxies, or the early stages of galaxies, began to form.
• A famous scientist named Isaac Newton explained this idea. He said that every piece of matter pulls on every other piece with a force that depends on how big they are and how far apart they are.

Dark Matter’s Role:

• Dark matter is another big player in how galaxies form. It mostly interacts through gravity.
• Scientists have noticed that galaxies have a lot more mass than we can actually see. This missing mass is mostly due to dark matter.
• Dark matter enhances the gravitational pull, helping regular matter come together to form galaxies.

Rotation and Disk Shape:

• As matter collapses, it keeps something called angular momentum, which is like a spinning motion.
• When mass changes how it’s, spread out, it can start to rotate. This spinning motion causes the material to flatten into a disk shape, leading to spiral galaxies.
• Gravity helps hold everything together and keeps stars moving in orbits around the center of the galaxy.

Building Bigger Structures:

• Gravitational forces help with a process called hierarchical structure formation. This means smaller structures can come together to form bigger ones, like galaxies and even bigger clusters of galaxies.
• These groups can interact with the cosmic web around them, helping each other grow and become stable.

Stability and Changes:

• Gravity not only helps shape how galaxies form, but it also affects how they change over time.
• Sometimes, galaxies can collide and merge together, which changes their shape and how they create new stars.
• The ongoing fight between the pulling force of gravity and the movement of stars in galaxies is key to figuring out what happens to a galaxy.

In summary, gravitational forces are essential for forming galaxies in the universe. The balance between gravity’s pull, the influence of dark matter, and how spinning motion is conserved all play a part in creating the many different types of galaxies we see today. Understanding these forces helps us learn more about how the universe evolved and what matter truly is.