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Frequently asked questions The total amount of dark energy increases as space expands. Doesn't that violate
conservation of energy?
Conservation of energy is not well-defined in
curved spacetime, since the
stress-energy tensor does not transform cleanly under change of coordinates.
[FAQ 1] References
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(+) DARK MATTER AND ATOMS
(-)DARK ENERGY
ATOMS:- FINISHED GOODS
DARK MATTER :- SUPPORTING MATERIAL
DARK ENERGY:- WASTE
CALCULATION :- 72%-23%+5%= 44% (DARK ENERGY). THE HUGE AMOUNT OF DARK ENERGY(72%) IS ATTRACTING THE SMALL AMOUNT OF DARK MATTER(23%) AND ATOMS(5%). . — Preceding unsigned comment added by RajnishGuunwal ( talk • contribs) 12:44, 12 December 2012
A more updated review on dark energy should be cited in the introduction. I suggest the book [1]
It could also serve as citation for several of the "citation needed", e.g. the possible failure of general relativity.— Preceding unsigned comment added by 2.246.99.116 ( talk • contribs) 07:50, 18 October 2014 (UTC)
IMO this should be its own section instead of a subsection of Theories of Dark Energy. Most articles of scientific theory for theories not already well-established have their contravened sections more conspicuous. It could probably use more content too but we've at least touched on the first of the Sarkar papers. We should probably expand the section with the V3 of their latest paper, "Evidence for anisotropy of cosmic acceleration" - https://arxiv.org/abs/1808.04597
So, radiation Density and mass Density declines but dark energy is constant as the universe expands? 3MRB1 ( talk) 11:37, 20 December 2023 (UTC)
Why is this article only listed as high importance and not top? I feel like this is just as important as dark matter (or more in my opinion), given the huge mass-energy content and its impact on the expansion of the universe. I assume this is determined based on Content assessment and Importance of topic. Given those are the correct links I have read, I am still unsure why this subject received only a high level. Xiberion ( talk) 12:19, 7 March 2024 (UTC)
As a non-physicist I found myself disliking this article more and more. I kept re-reading it trying to answer basic questions, and could not. Maybe I am simply not understanding what anyone reading the page ought to be able to understand, but here are some thoughts anyway.
The first sentence treats dark energy as an established fact of the universe, and the second sentence seems to obfuscate the fact that dark energy is a component of one theory (lambda CDM). Immediately I am not clear that the people working on dark energy, or at least the people working on this wikipedia page, are differentiating between evidence for accelerating expansion of the universe, and evidence for dark energy. The two are not the same thing. The history of discovery section is more like "here are some things that are like dark energy". Try substituting "pink unicorn" for "dark energy" in the first few sentences to get an idea of how this looks. The vagueness, lack of clarity, and relative sparsity of treatment of counterarguments in the article makes the it look like a house of cards, and/or a mishmash of things that are hard to blend into a coherent whole. There's nothing wrong with having an opinion, but let's please be objective and clear.
Anyway here are some suggestions: (1) explicitly state whether it is known that dark energy exists, (2) make clear the difference between evidence for accelerating expansion, and evidence for dark energy (a possible explanation of the accelerating expansion, if that is actually what is meant by dark energy), (3) make clear which theories dark energy is present in and which it is not, (4) change the title of the "In Philosophy of Science" to something that is more clearly a criticism of dark energy, and put this criticism very close to the front of the document, if there is significant skepticism of dark energy in the physics community. Put another way, do you really want to emphasize in this section "In Philosophy of Science" that dark energy's main role in Merritt's discussion is to serve as an example? Or is this a possibly valid criticism of dark energy? What are the responses to this criticism? "Lack of scientific consensus"???, (5) explain the relation between "energy" in "dark energy" and energy in the sense of more every day physics, e.g., the conservation of energy, (6) explain more clearly the history of the concept of dark energy with clear separation of the concept of dark energy as an explanation for accelerating expansion of the universe (or whatever dark energy is supposed to do), and accelerating expansion of the universe (or probably more precisely, observations made of the universe), (7) consider moving some material into other pages. if dark energy is a super important wikipedia page then maybe the article should be only a few pages long. 2601:600:877F:DD20:BC4F:ED64:C1C8:C377 ( talk) 04:47, 11 March 2024 (UTC)
Seems recent studies suggest that Dark Energy thinking is seriously "Flawed" [1] - or that Dark Energy doesn't even exist at all [2] [3] - if interested, my related pubished NYT comments may be relevant [4] - in any case - Worth adding to the main " Dark Energy" article - or Not? - Comments Welcome - Stay Safe and Healthy !! - Drbogdan ( talk) 13:45, 5 April 2024 (UTC)
NOTE: A related discussion has been centralized on " physics Wikiproject", and can be found at the following link => " Wikipedia talk:WikiProject Physics/Archive April 2024#Dark Energy is Flawed or Nonexistent?" - iac - Stay Safe and Healthy !! - Drbogdan ( talk) 22:19, 8 April 2024 (UTC)
References
Drbogdan ( talk) 13:45, 5 April 2024 (UTC)
J/m3 = unit of energy density = Joules per cubic meter.
g/cm3 = unit of density = Grams = per cubic centimeter.
1 Joule = 107 ergs in Centimetre–gram–second system of units (CJS units).
1 meter = 102 centimeters (cm's), so 1 cubic meter = 106 cubic cm's.
I'm going to delete "(≈7×10−30 g/cm3)", because it is obviously wrong.
Can someone please provide a clear citation for "6×10−10 J/m3"?
I tried to review notes [1] - [5] and was unable to find a number for "energy density". Thanks, DavidMCEddy ( talk) 18:17, 30 April 2024 (UTC)
This
level-4 vital article is rated C-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||||||||||||||||||||||
|
Frequently asked questions The total amount of dark energy increases as space expands. Doesn't that violate
conservation of energy?
Conservation of energy is not well-defined in
curved spacetime, since the
stress-energy tensor does not transform cleanly under change of coordinates.
[FAQ 1] References
|
This page has archives. Sections older than 120 days may be automatically archived by Lowercase sigmabot III. |
This article links to one or more target anchors that no longer exist.
Please help fix the broken anchors. You can remove this template after fixing the problems. |
Reporting errors |
(+) DARK MATTER AND ATOMS
(-)DARK ENERGY
ATOMS:- FINISHED GOODS
DARK MATTER :- SUPPORTING MATERIAL
DARK ENERGY:- WASTE
CALCULATION :- 72%-23%+5%= 44% (DARK ENERGY). THE HUGE AMOUNT OF DARK ENERGY(72%) IS ATTRACTING THE SMALL AMOUNT OF DARK MATTER(23%) AND ATOMS(5%). . — Preceding unsigned comment added by RajnishGuunwal ( talk • contribs) 12:44, 12 December 2012
A more updated review on dark energy should be cited in the introduction. I suggest the book [1]
It could also serve as citation for several of the "citation needed", e.g. the possible failure of general relativity.— Preceding unsigned comment added by 2.246.99.116 ( talk • contribs) 07:50, 18 October 2014 (UTC)
IMO this should be its own section instead of a subsection of Theories of Dark Energy. Most articles of scientific theory for theories not already well-established have their contravened sections more conspicuous. It could probably use more content too but we've at least touched on the first of the Sarkar papers. We should probably expand the section with the V3 of their latest paper, "Evidence for anisotropy of cosmic acceleration" - https://arxiv.org/abs/1808.04597
So, radiation Density and mass Density declines but dark energy is constant as the universe expands? 3MRB1 ( talk) 11:37, 20 December 2023 (UTC)
Why is this article only listed as high importance and not top? I feel like this is just as important as dark matter (or more in my opinion), given the huge mass-energy content and its impact on the expansion of the universe. I assume this is determined based on Content assessment and Importance of topic. Given those are the correct links I have read, I am still unsure why this subject received only a high level. Xiberion ( talk) 12:19, 7 March 2024 (UTC)
As a non-physicist I found myself disliking this article more and more. I kept re-reading it trying to answer basic questions, and could not. Maybe I am simply not understanding what anyone reading the page ought to be able to understand, but here are some thoughts anyway.
The first sentence treats dark energy as an established fact of the universe, and the second sentence seems to obfuscate the fact that dark energy is a component of one theory (lambda CDM). Immediately I am not clear that the people working on dark energy, or at least the people working on this wikipedia page, are differentiating between evidence for accelerating expansion of the universe, and evidence for dark energy. The two are not the same thing. The history of discovery section is more like "here are some things that are like dark energy". Try substituting "pink unicorn" for "dark energy" in the first few sentences to get an idea of how this looks. The vagueness, lack of clarity, and relative sparsity of treatment of counterarguments in the article makes the it look like a house of cards, and/or a mishmash of things that are hard to blend into a coherent whole. There's nothing wrong with having an opinion, but let's please be objective and clear.
Anyway here are some suggestions: (1) explicitly state whether it is known that dark energy exists, (2) make clear the difference between evidence for accelerating expansion, and evidence for dark energy (a possible explanation of the accelerating expansion, if that is actually what is meant by dark energy), (3) make clear which theories dark energy is present in and which it is not, (4) change the title of the "In Philosophy of Science" to something that is more clearly a criticism of dark energy, and put this criticism very close to the front of the document, if there is significant skepticism of dark energy in the physics community. Put another way, do you really want to emphasize in this section "In Philosophy of Science" that dark energy's main role in Merritt's discussion is to serve as an example? Or is this a possibly valid criticism of dark energy? What are the responses to this criticism? "Lack of scientific consensus"???, (5) explain the relation between "energy" in "dark energy" and energy in the sense of more every day physics, e.g., the conservation of energy, (6) explain more clearly the history of the concept of dark energy with clear separation of the concept of dark energy as an explanation for accelerating expansion of the universe (or whatever dark energy is supposed to do), and accelerating expansion of the universe (or probably more precisely, observations made of the universe), (7) consider moving some material into other pages. if dark energy is a super important wikipedia page then maybe the article should be only a few pages long. 2601:600:877F:DD20:BC4F:ED64:C1C8:C377 ( talk) 04:47, 11 March 2024 (UTC)
Seems recent studies suggest that Dark Energy thinking is seriously "Flawed" [1] - or that Dark Energy doesn't even exist at all [2] [3] - if interested, my related pubished NYT comments may be relevant [4] - in any case - Worth adding to the main " Dark Energy" article - or Not? - Comments Welcome - Stay Safe and Healthy !! - Drbogdan ( talk) 13:45, 5 April 2024 (UTC)
NOTE: A related discussion has been centralized on " physics Wikiproject", and can be found at the following link => " Wikipedia talk:WikiProject Physics/Archive April 2024#Dark Energy is Flawed or Nonexistent?" - iac - Stay Safe and Healthy !! - Drbogdan ( talk) 22:19, 8 April 2024 (UTC)
References
Drbogdan ( talk) 13:45, 5 April 2024 (UTC)
J/m3 = unit of energy density = Joules per cubic meter.
g/cm3 = unit of density = Grams = per cubic centimeter.
1 Joule = 107 ergs in Centimetre–gram–second system of units (CJS units).
1 meter = 102 centimeters (cm's), so 1 cubic meter = 106 cubic cm's.
I'm going to delete "(≈7×10−30 g/cm3)", because it is obviously wrong.
Can someone please provide a clear citation for "6×10−10 J/m3"?
I tried to review notes [1] - [5] and was unable to find a number for "energy density". Thanks, DavidMCEddy ( talk) 18:17, 30 April 2024 (UTC)