Questions about Universe expansion

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SUMMARY

The discussion centers on the expansion of the Universe and its relationship with local gravitational fields. It is established that while the Universe is expanding, local gravitational forces, particularly at stellar and galactic levels, counteract this expansion, preventing observable local effects. Additionally, the perception of faster expansion at the edges of the Universe is clarified; scientists account for the fact that observations reflect events that occurred nearly 14 billion years ago, emphasizing that all points in the Universe are at the center of their own observable regions.

PREREQUISITES
  • Understanding of gravitational forces and their effects on cosmic structures
  • Familiarity with the concept of the Observable Universe
  • Knowledge of the finite speed of light and its implications for astronomical observations
  • Basic grasp of cosmological expansion theories
NEXT STEPS
  • Research the implications of local gravitational fields on cosmic expansion
  • Study the concept of the Observable Universe and its significance in cosmology
  • Learn about the finite speed of light and its role in astronomical observations
  • Explore advanced cosmological models that explain the expansion of the Universe
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Astronomers, astrophysicists, and students of cosmology seeking to deepen their understanding of Universe expansion and gravitational influences on cosmic structures.

AlSo
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I have two questions about the expansion of the Universe. 1. Why is there no local expansion around us, is local gravitational field strong enough to prevent this? How does the vector of gravity act to prevent expansion in multi-directions? 2. When scientists observe the expanding Universe, and comment that "further Universe expands even faster", have they considered the fact that what they see "at the edge" had actually happened nearly 14 billion years ago? Thank you.
 
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1) Yes you are correct. Theoretically universe expansion holds on all levels, but any expansion on the stellar, or even close galactic level is canceled out by gravitational attraction.

2) Yes they do.
 
thanks Vorde!
 
thanks phinds, that is very useful. I always feel uneasy when I hear scientists say "the farther Universe expands faster"----this seemed to commit the same mistake we made centuries ago----placing the Earth at the centre of the Universe. Cheers!
 
AlSo said:
thanks phinds, that is very useful. I always feel uneasy when I hear scientists say "the farther Universe expands faster"----this seemed to commit the same mistake we made centuries ago----placing the Earth at the centre of the Universe. Cheers!

The Earth is at the center of the Observable Universe but this doesn't imbue it with any preferential frame - all points are at the center of their own observable universe - due to the expansion of the Universe and the finite speed of light.

The furthest places we can "see" do appear to be accelerating away from us but in actuality it is just the consequence of a scale factor over a bigger area of space - its quite a logical assumption.
 
thanks Cosmo Novice!
 

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