Chapter 1: The Cosmic Plane

Why is it that all planets seem to orbit around the sun in a nearly flat plane? When we examine other celestial systems, we observe a similar alignment. This raises intriguing questions: Are galaxies also disk-shaped? Why don’t we see galaxies and planetary systems taking on spherical forms, for instance?

The alignment of celestial bodies in a single plane can be attributed to two main factors: the continuous collisions among particles and the dynamics of three-dimensional space. The formation of cosmic entities begins with enormous gas-dust clouds of various shapes. As these clouds are compressed by their own gravitational pull, the dust particles within them collide and coalesce. While tracking the movement of individual particles is nearly impossible, if we consider the cloud as a whole, it reveals a common momentum relative to its center of mass, which dictates the plane of rotation.

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Section 1.1: Understanding Cosmic Dynamics

It’s challenging to observe the overarching direction of rotation within a cloud, yet mathematical models consistently suggest that it exists and usually prove to be accurate. The direction of the total momentum is influenced by a variety of random factors, including the cloud’s shape, size, and interactions with other clouds and stars. Consequently, the plane that initially possesses slightly more momentum will ultimately capture surrounding matter through numerous collisions, defining the general axis around which the object will rotate.

Section 1.2: The Role of Particle Interactions

When particles rotate outside of this defined plane, they tend to collide with one another and merge, resulting in a loss of kinetic energy. Over time, this process neutralizes their rotation. Thus, opposing momenta from rotations “up” and “down” will balance each other out, aligning with the principle of conservation of momentum—since the total momentum was zero before the collision, it remains zero afterward.

Chapter 2: The Formation of Cosmic Structures

Particles that rotate within the plane defined by the common momentum are less likely to experience a loss of rotation, as their momenta are not countered by other forces. In an isolated system, momentum remains constant, meaning that the degree of rotation cannot diminish. Matter rotating in planes parallel to the defined one is gradually drawn into it by centrifugal forces.

Have you ever noticed how a chef spins a thick pizza dough in the oven to stretch it thinner? A similar process occurs with gas-dust clouds. As these clouds rotate, they flatten into a disk shape, resembling the structure of spiral galaxies or planetary systems, from which stars and planets eventually form.

In a hypothetical four-dimensional space, the dynamics would differ significantly. There would be two planes of gas rotation, and without a distinct "up" or "down" direction, particles would not lose energy due to collisions, resulting in the cloud remaining intact.

The first video titled "Why Do All The Planets Orbit In The Same Plane?" delves into the mechanics of planetary orbits and the reasons behind their alignment.

Another insightful video titled "Why Do the Planets Orbit in the Same Plane?" further explores the concepts discussed and provides a visual understanding of these cosmic phenomena.

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