Question About Conservation of Energy, the Cosmological Constant and Dark Energy

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Discussion Overview

The discussion revolves around the relationship between the conservation of energy, the cosmological constant, and dark energy, particularly in the context of spacetime geometry. Participants explore theoretical implications and conceptual challenges regarding energy conservation in an expanding universe.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant expresses confusion about how energy can be created as the vacuum of space expands, suggesting this contradicts the conservation of energy.
  • Another participant asserts that while space is flat according to measurements, spacetime is curved, indicating a distinction between the two.
  • A later reply acknowledges that spacetime is curved near massive objects but questions whether it is broadly flat on a cosmic scale.
  • Another response challenges the notion of broad flatness in spacetime within the context of the Lambda Cold Dark Matter (LCDM) model, stating that spacetime is not flat, only space is.

Areas of Agreement / Disagreement

Participants do not reach consensus on the nature of spacetime and its implications for energy conservation, with multiple competing views presented regarding the curvature of spacetime and its relationship to the cosmological constant and dark energy.

Contextual Notes

Limitations include the potential misunderstanding of spacetime curvature, the implications of the LCDM model, and the nuances of energy conservation in curved spacetime versus flat space.

richard.coppack
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I am confused about the cosmological constant and dark energy. In the most accepted theory, energy is created as the vacuum of space expands. This contravenes the conservation of energy. The law of conservation of energy does not hold in curved spacetime but isn't our universe flat spacetime ? What am I missing here ?
 
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richard.coppack said:
isn't our universe flat spacetime ?
Nope. To the best of our measurements space is flat but spacetime is curved.
 
Dale said:
Nope. To the best of our measurements space is flat but spacetime is curved.
Thank you for your reply. Yes, spacetime is curved near a massive object. On a cosmic scale, isn't spacetime broadly flat?
 
richard.coppack said:
Thank you for your reply. Yes, spacetime is curved near a massive object. On a cosmic scale, isn't spacetime broadly flat?
No, spacetime in the LCDM model is not flat. Just space.
 

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