Is Dark Energy the Answer to the Accelerating Universe and Big Bang Conundrums?

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Discussion Overview

The discussion revolves around the concepts of dark energy and its relation to the accelerating expansion of the universe, as well as issues surrounding the Big Bang theory. Participants explore the implications of these ideas on cosmology, including the nature of dark matter and the interpretation of early universe conditions.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • One participant suggests that the observation of distant objects moving faster implies they were slowing down in the past, questioning the need for dark energy and dark matter.
  • Another participant counters that dark energy is related to the acceleration of the universe's expansion, which became dominant approximately 6 or 7 billion years ago, while dark matter contributes to gravitational effects rather than expansion dynamics.
  • A third participant points out that the formula E=1/2MV² is not applicable at relativistic speeds, implying limitations in the initial participant's reasoning.
  • There is a discussion about the Big Bang theory, with one participant emphasizing that it does not address conditions "before the BB" and focuses on the universe's evolution starting from a specific point after the singularity.
  • Another participant clarifies that the expanding universe concept leads to the Big Bang idea, and distinguishes between dark matter and dark energy, noting that dark energy is proposed to explain the observed acceleration of expansion.

Areas of Agreement / Disagreement

Participants express differing views on the implications of observations related to the universe's expansion and the roles of dark energy and dark matter. There is no consensus on the interpretations of these concepts, and the discussion remains unresolved.

Contextual Notes

Participants highlight misconceptions and clarify that the Big Bang theory does not make assumptions about conditions prior to the singularity. There are also references to the limitations of classical physics in the context of relativistic speeds.

rogerpendleto
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Two Issues:

1 Accellerating Universe Expansion (Inflation)

As I understand this this arises out of the observation that the further away object are, the faster they are moving, (relative to us). This I assume is the origin of the search for “Dark Matter” & “Dark Energy”

Surely if a star 1,000 light years away is traveling faster than a star 100 LY away this means that 1000 years ago it was traveling faster than it was 100 years ago – ergo it is SLOWING DOWN. Does this not remove some of the problems we are trying to solve?

1 Big Bang Issues.

Many of the currently available books written as explanations of the BB and posing the questions of the issues of inflation mention what happens in the “first Micro second” or the “first 4 minutes”. If we assume that just before the BB there was no mass and nearly infinite energy then from

E= 1/2MV² then V must beclose to the limiting velocity C. Now Uncle Albert told us that time slows down as relative velocity increases so on this model one second could be the sam as 100 present day years. As all of our calculations are based on our experience of present “earth” seconds does this not go a long way to explaining the mysteries of the first few seconds?
 
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All of your statements represent common misconceptions about these topics that have been explored many times here on this forum. I suggest a forum search and/or further reading on cosmology.

Also, the expanding universe is related to dark energy. Dark matter is a contributing factor to slowing down the expansion, not speeding it up as you seem to think, but the effects of dark energy became dominant about 6 or 7 billion years ago. Dark matter was discovered because of its gravitational effect on large structures (galaxies) and not because of anything relating to the expansion of the universe or the acceleration of that expansion.

You might take a look at the link in my signature.

EDIT: One other thing. About your statement "If we assume that just before the BB there was no mass and nearly infinite energy then from ...", the Big Bang Theory does not say ANYTHING about "before the BB", it is a theory about the evolution of the universe starting at about one Plank Time after the singularity but says nothing about the singularity, so we don't make any assumptions about "before the BB" or before one Plank Time.
 
... and finally E= 1/2MV² is Newtonian formula, not valid when v-->c
 
As I understand this this arises out of the observation that the further away object are, the faster they are moving, (relative to us). This I assume is the origin of the search for “Dark Matter” & “Dark Energy”

The observation you described is the idea behind the concept of an expanding universe, leading to the idea of a big bang.

Dark matter is a separate issue, based on observations of stellar motion in galaxies and relative motion of galaxies within clusters.

Dark energy is proposed as an explanation for the observation that the expansion is speeding up, rather than slowing down. If there was no dark energy there still would be expansion.
 

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