Is Dark Energy the Key to Understanding the Expansion of the Universe?

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Discussion Overview

The discussion revolves around the concept of Dark Energy and its implications for the expansion of the universe. Participants explore its relationship with Dark Matter, the Standard Model of particle physics, and potential practical applications of vacuum energy, as well as the nature of these components in cosmology.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant references observations from the Chandra X-Ray Observatory suggesting that galaxies are not accumulating more matter over time, attributing this to Dark Energy, or Vacuum Energy, which may imply significant gravitational effects from empty space.
  • Another participant supports the lambdaCDM model, stating that it includes approximately 74% Dark Energy, 22% Dark Matter, and 4% regular visible matter, suggesting both Dark Energy and Dark Matter are beyond the Standard Model.
  • Questions are raised about the speculative nature of Dark Energy, with one participant seeking to understand what it consists of, similar to how WIMPs are considered for Dark Matter.
  • There is a discussion about comparing Dark Energy, Dark Matter, and Regular Matter, questioning whether gravity serves as a common measurement and how Dark Energy might be characterized in terms of its effects on matter.

Areas of Agreement / Disagreement

Participants express various viewpoints regarding the nature and implications of Dark Energy and Dark Matter, with no consensus reached on the specifics of what Dark Energy consists of or how it compares to other forms of matter.

Contextual Notes

Participants acknowledge the speculative aspects of Dark Energy and its relationship to established models, indicating a need for further exploration of its properties and implications.

sanman
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The Chandra X-Ray Observatory has revealed that galaxies aren't accumulating lots more matter over time:

http://www.csmonitor.com/2008/1218/p01s07-usgn.html

http://blogs.nature.com/news/thegreatbeyond/2008/12/new_clues_for_dark_energy_1.html

http://blog.newsweek.com/blogs/labnotes/archive/2008/12/16/may-the-dark-energy-be-with-you.aspx

http://arstechnica.com/journals/science.ars/2008/12/17/lighting-up-dark-energy


This is then attributed to the effect of "Dark Energy", more properly identified as Vacuum Energy, or Einstein's Cosmological Constant.

So to me, this means that not only can a large mass have significant gravitational force, but even a large span of empty space can have a large gravitational force associated with it.

So how can we then make use of this knowledge?
I recognize that one practical implication is that the universe is not slowing down in its expansion, but could keep going indefinitely.

And then what?
I remember some experiment by researchers at UC Riverside, showing that the Casimir Effect from vacuum energy could be turned into a nano-sized spring-device. They had 2 corrugated surfaces placed close to each other, at some miniscule separation distance, and the Casimir Effect caused the apparatus to behave like a spring.

Is Dark Energy considered to be physics beyond the Standard Model, if it's merely confirming Einstein's original conjecture on the Cosmological Constant?
Also, does this then diminish the need for Dark Matter to explain the observed nature of the universe?
 
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Its yet another piece of evidence that confirms the now standard lambdaCDM scenario 'the concordance model'. Eg ~74% dark energy, 22% darkmatter and 4% regular visible matter.

Dark energy and Dark matter are both presumably physics beyond the standard model of particle physics.
 
In which case, what are the speculative conjectures about what's causing the Dark Energy effect? In the case of Dark Matter, we have WIMPs as an imagined animal. What does the Dark Energy consist of?
 
Haelfix said:
Its yet another piece of evidence that confirms the now standard lambdaCDM scenario 'the concordance model'. Eg ~74% dark energy, 22% darkmatter and 4% regular visible matter.

Dark energy and Dark matter are both presumably physics beyond the standard model of particle physics.


I'd like to also ask, how can we compare Dark Energy, Dark Matter, and Regular Matter on a common scale? Aren't they all like apples, oranges and grapes?

Is gravity the common means of measurement?

If regular matter and even dark matter exhibit conventional gravity, then what do we call the force shown by dark energy -- antigravity? Is it working to keep matter apart, or is it just working to stretch out the space that lies between matter as much as possible?
 

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