Our universe as an expanding sponge that is constantly falling.

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Discussion Overview

The discussion revolves around the analogy of the universe as an expanding sponge that is constantly falling. Participants explore the implications of this analogy for understanding the expansion of the universe, the nature of galaxies, and the concept of cosmic structure. The conversation touches on theoretical and conceptual aspects of cosmology.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant proposes that the universe's expansion can be likened to a sponge that expands while falling, suggesting that galaxies and stars are akin to particles within the sponge.
  • Another participant argues that the analogy is flawed, stating that cosmological expansion does not involve an external volume or forces acting on it, emphasizing that the universe does not have an "outside."
  • A third participant expresses uncertainty about the appropriate section for the thread, indicating a lack of clarity on categorization.
  • Another participant characterizes the discussion as "science fantasy," implying skepticism about the analogy's validity.
  • One participant notes that understanding the expansion of the universe requires mathematical clarity, suggesting that the analogy may lack rigor.
  • A later reply reiterates that cosmology cannot be effectively discussed through analogy and encourages participants to refer to existing threads on the subject.

Areas of Agreement / Disagreement

Participants express disagreement regarding the validity of the sponge analogy for cosmological expansion. Some participants challenge the analogy, while others find it a useful conceptual tool. The discussion remains unresolved with multiple competing views present.

Contextual Notes

Participants highlight limitations in the analogy, including the absence of external forces and the need for mathematical understanding in cosmological discussions. The conversation reflects a mix of speculative ideas and critical responses.

Shu Sheng
Guys I know this is absurd, but it kinda makes sense to me. Recently, while i was doing housekeeping, I asked my brother to throw a piece of sponge down. He compressed the sponge and dropped it down. While the compressed sponge was falling, I saw it expanding. Seeing this, I realized that the expansion of the sponge is similar to the concept of our universe expanding. This led to me wondering, how is it possible for our earth, solar system and Galaxy to suspend in the universe? Is it because our universe is like a falling compressed sponge, which is just trying to expand to its original size? Because the universe is constantly falling, all the galaxies, solar systems and stars fall together with the universe. Also, the speed of our universe falling could be so fast, maybe falling at the speed of light, that vacuums are created in space, that led to us not realising it.The stars and galaxies could be like the particles in a piece of sponge. While the universe expands, it sucks in new material from beyond the universe and this brings in energy which kept our system moving.
 
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I realized that the expansion of the sponge is similar to the concept of our universe expanding.
It's almost, but not quite, entirely unlike a sponge expanding. The cosmological expansion is different in every important respect.

i.e. The sponge expands into a surrounding volume and is acted on by outside forces - it also expands by virtue of filling it's cavities with material from the surrounding volume. This is all stuff the Universe does not have or do. There is no existence "outside" the Universe - that is what "Universe" means.

Thus the short answer to your speculative questions is "no".
You cannot do cosmology by analogy.
 
Ok actually I'm not sure where I should put this thread but I can't find the correct section to put it under
 
I think this is science fantasy actually
 
Head of forum you can remove this if you want :)
 
Understanding expansion of the universe requires math to make it clear.
 
Simon Bridge said:
You cannot do cosmology by analogy.

Agreed.
Shu, there are about a thousand threads on this subject here in the cosmology forum. Please read a few of them and avoid personal speculation.

Thread locked.
 

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