Are primordial fluctuations the source of all structure?

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Discussion Overview

The discussion centers on the role of quantum fluctuations in the formation of both large-scale cosmological structures and human-scale structures. Participants explore whether these fluctuations can account for density variations at different scales, including atomic and human scales, and the implications of these fluctuations on the predictability of cosmic structures.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions whether quantum fluctuations are responsible for human-scale structures, seeking analysis on how these fluctuations create density variations at various scales.
  • Another participant asserts that initial fluctuations lead to density variations that collapse into galaxies, stars, and planets, but emphasizes that the final structure is influenced by random variations later in cosmic history.
  • A different viewpoint argues that quantum fluctuations are not random but governed by equations, suggesting a deterministic aspect to these phenomena.
  • In response, it is noted that while the governing equations predict probabilities, the exact outcomes remain unpredictable, which introduces a level of randomness to the fluctuations.
  • One participant firmly states that quantum fluctuations do not account for human-scale structures, arguing that the current cosmological model does not intend to address such scales and focuses on gravitational clumping due to density inhomogeneities.
  • A later reply challenges the certainty of claims made about quantum fluctuations, emphasizing the need for careful language in scientific discussions.

Areas of Agreement / Disagreement

Participants express differing views on the nature of quantum fluctuations, with some asserting randomness and others advocating for a deterministic interpretation. There is no consensus on whether quantum fluctuations account for human-scale structures, with some participants rejecting this idea outright.

Contextual Notes

The discussion highlights the limitations of the current cosmological model in addressing structures at human scales and the unresolved nature of the relationship between quantum fluctuations and predictability in cosmic structures.

Ahmedbadr132
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TL;DR
Are primordial fluctuations the source of all structure?
Hello friends .
I was asking whether quantum fluctuations created not only large scale cosmological structure but also our human-scale structure.
There is no mention and analysis of this aspect of the theory .
Please can anyone analyze it for me . How these quantum fluctuations create our human scale density variations and also atomic scale.
 
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The initial fluctuations cause density variations that eventually collapse into galaxies, stars and planets. Quantum phenomena aren't completely predetermined, however, so the exact final structure isn't completely predetermined by the initial fluctuations because it also depends on random variation later in history.
 
Ibix said:
The initial fluctuations cause density variations that eventually collapse into galaxies, stars and planets. Quantum phenomena aren't completely predetermined, however, so the exact final structure isn't completely predetermined by the initial fluctuations because it also depends on random variation later in history.
I do not think so
Quantum fluctuations are not random . They are governed by equations.
 
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Ahmedbadr132 said:
Quantum fluctuations are not random . They are governed by equations.
The equations we have predict probabilities of outcomes. Exact outcomes are, however, unpredictable as far as we know. So yes, the fluctuations are random.
 
Ahmedbadr132 said:
I was asking whether quantum fluctuations created not only large scale cosmological structure but also our human-scale structure.
No, they didn't.

Ahmedbadr132 said:
There is no mention and analysis of this aspect of the theory .
That's because the theory does not, and is not intended to, account for structure on human scales.

More generally, the theory, by which I assume you mean our best current cosmological model of the universe including quantum fluctuations that left "imprints" in the initial conditions at the end of inflation, does not, and is not intended to, account for any structure that is not the result of gravitational clumping due to inhomogeneities in density.
 
Ahmedbadr132 said:
Quantum fluctuations are not random
You should be careful about making categorical statements of "fact" when your "fact" is in fact wrong. This is a a science forum and as member @PAllen said many moons ago
Note, we are not called the "idle speculation without understanding or knowledge forums".
 
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