Why does everything in the Universe form a ball or Sphere?

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Discussion Overview

The discussion revolves around the reasons why celestial bodies such as planets and stars tend to form spherical shapes. Participants explore the role of gravity in this phenomenon, as well as the implications of energy efficiency in shape formation. The conversation includes theoretical considerations and speculative questions about alternative shapes in the universe.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions whether gravity is the sole reason for spherical shapes and wonders if gravity itself can be visualized or understood as a shape.
  • Another participant explains that the gravitational field of a planet or star pulls mass toward its center, leading to a spherical shape due to the fluid-like behavior of large bodies over time.
  • It is noted that smaller bodies, like asteroids, do not form spheres because their gravitational pull is insufficient to overcome their mechanical strength, resulting in irregular shapes.
  • Some participants assert that a sphere has the lowest surface area for a given volume, making it the most energy-efficient configuration.
  • A question is raised about the possibility of discovering more energy-efficient shapes than spheres, referencing historical geometric figures and their potential implications.
  • One participant suggests that differential calculus supports the idea that a sphere is the most efficient shape, considering structural limits on height and weight.
  • Another participant posits that any non-spherical shape will eventually lead to a spherical form due to natural processes like erosion and disturbances.

Areas of Agreement / Disagreement

Participants generally agree on the role of gravity and energy efficiency in the formation of spherical shapes, but there is speculation about the existence of alternative shapes and the implications of such discoveries. The discussion remains open-ended without a consensus on these speculative aspects.

Contextual Notes

Some assumptions about the nature of gravity and energy efficiency are present, but these are not universally accepted or resolved. The discussion also touches on the limitations of current understanding regarding smaller celestial bodies and their shapes.

blackstar5000
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I want to know why everything in the universe forms a Ball or Sphere? Is gravity the cause of this? If so why? For example, If we were to pick the sphere apart can we see the source of gravity? Is gravity also a ball or sphere and can we grasp and see it? Why do we not ever see square planets or hexagon shaped stars etc...? Sorry, I am new to the forum and I tend to ask strange questions.
 
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Planets and stars are round because their gravitational field acts as though it originates from the center of the body and pulls everything toward it. With its large body and internal heating a planet or star behaves like a fluid, and over long periods of time succumbs to the gravitational pull from its center of gravity. The only way to get all the mass as close to planet's center of gravity as possible is to form a sphere.

With much smaller bodies, such as the 20-kilometer asteroids the gravitational pull is too weak to overcome the asteroid's mechanical strength. As a result, these bodies do not form spheres. Rather they maintain irregular, fragmentary shapes.
 
A sphere has the lowest possible surface area required to bound any given volume.
 
Chronos said:
A sphere has the lowest possible surface area required to bound any given volume.

Therefore, it is the most energy-efficient configuration.
 
Are there more energy efficient shapes? Spheres seem to be the most common of course but the universe is a big place and we have much searching to do, is it possible that we find or someone comes up with a shape more efficient than a sphere? Not saying that it is but for example Leonardo's 72 sided figure? What would be the implications of finding this out sort of like aerodynamics but for energy conservation?
 
I believe differential calculus will tell us that a sphere is the most efficient shape. The taller the mountain gets, the heavier it gets, which means at some point it won't be able to support itself and crash to the surface
 
Right, any other shape is just going to be a spherical planet with some really weird mountains on it. And if there's any kind of disturbance that knocks a piece off, regardless of whether its weather, tectonic activity, meteor impacts, the result is going to be that pieces roll downhill. Give it enough time, and you get a sphere (that's flattened a bit because of its rotation).
 

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