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"...Prof. Young-Wook Lee (Yonsei Univ., Seoul), who led the project said, "Quoting Carl Sagan, extraordinary claims require extraordinary evidence, but I am not

"...Prof. Young-Wook Lee (Yonsei Univ., Seoul), who led the project said, "Quoting Carl Sagan, extraordinary claims require extraordinary evidence, but I am not sure we have such extraordinary evidence for dark energy. Our result illustrates that dark energy from SN cosmology, which led to the 2011 Nobel Prize in Physics, might be an artifact of a fragile and false assumption."" Is he implying that other cosmologists have proceeded as if dark energy is well evidenced?

AnimalMuppet 7y ago
It is my impression that dark energy is generally accepted in cosmology. Whether that counts as "proceeding as if dark energy is well evidenced" is perhaps a different question. If everyone believes it's there, but nobody knows what it is, well... there was still something that convinced them that it was there. That something should be evidence. Is it enough to count as "well evidenced"? Perhaps not, especially if this new study is correct that one piece of the evidence does not actually support dark energy.
- ncmncm 7y ago
  I don't know of any other evidence for dark energy, other than that mathematical physicists think the equations would be prettier with some, although they sort of wish there was more. It is quite embarrassing that the value was so close to zero without being zero, so that might be one embarrassment less. We already knew there was likely to be something fishy about the most distant supernovas, because we have two divergent values for the Hubble constant, one of them based on these same supernovas.
  - AnimalMuppet 7y ago
    Hmm. Is this new result in the right direction to solve the Hubble Constant problem?
    - ncmncm 7y ago
      Haha, it would be fun if we now have three Hubble constants.
      - mindcrime 7y ago
        https://xkcd.com/927/ https://xkcd.com/927/
      - trhway 7y ago
        my personal favorite value for the Hubble constant is the "c" divided by the age of Universe, it results in 70.8 km/s/Mpc, right in the middle of the other 2 established Hubble constant's values, a very nice coincidence that the objects at the Universe age distance are running away exactly with "c".
        AnimalMuppet 7y ago
        A coincidence? I think it might be an identity. But that would mean that disputes about the value of the Hubble Constant are also disputes about the age of the universe, and vice versa.
        ncmncm 7y ago
        Right, and that has been revised a few times recently.
  - ailideex 7y ago
    > I don't know of any other evidence for dark energy, other than that mathematical physicists think the equations would be prettier with some, although they sort of wish there was more. https://en.wikipedia.org/wiki/Dark_energy#Evidence_of_existence https://en.wikipedia.org/wiki/Dark_energy#Evidence_of_existe...
- StanislavPetrov 7y ago
  >If everyone believes it's there, but nobody knows what it is, well... there was still something that convinced them that it was there. The article stipulates what convinced these people that it was there, namely that they rested their conclusions on an assumption that turned out to be wrong. This result is based on the assumption that the corrected luminosity of SN Ia through the empirical standardization would not evolve with redshift. Which is another good reason not to make conclusive judgements based on unproven assumptions (not that everyone that "dark energy" must exist, but many did, and some people still cling to it even if the face of this study). It is also a good example of why one should never give credence to a theory or a supposition based on how many other people give it credence - stick to what you can prove.
carbocation 7y ago
This doesn't really address your point, but the 2011 physics Nobel [1] said that "What is known is that dark energy constitutes about three quarters of the Universe." Not saying the Nobel write-ups constitute evidence, but dark energy has certainly been popular, at least. 1 = https://www.nobelprize.org/prizes/physics/2011/press-release/ https://www.nobelprize.org/prizes/physics/2011/press-release...
- doodliego 7y ago
  The Luminiferous Aether was popular too.
  - stefantalpalaru 7y ago
    > The Luminiferous Aether was popular too. It still is: https://en.wikipedia.org/wiki/Quantum_field_theory https://en.wikipedia.org/wiki/Quantum_field_theory
phkahler 7y ago
>> Is he implying that other cosmologists have proceeded as if dark energy is well evidenced? As a non-cosmologist just reading HN I would say yes. Not quite as extensively as Dark matter though. I personally think that's a mistake too based on my limited research on the topic. If these are both overturned it will be a huge blow to "scientists" credibility in the eyes of the public. That's how invested they are.
- coliveira 7y ago
  > If these are both overturned it will be a huge blow to "scientists" credibility This is nonsense. Scientists have been wrong in several occasions, it is just part of the profession. For example, in the years leading to the discovery of relativity, many physicists believed there was something called "ether" that worked to fix the speed of light that they had evidence to be the same in all directions.
  - deleted 7y ago
    [deleted]
  - ShorsHammer 7y ago
    Generally called aether, believe that ether is a misspelling which has lingered. https://en.wikipedia.org/wiki/Aether_theories https://en.wikipedia.org/wiki/Aether_theories
    - mishac 7y ago
      I believe it's just a regional spelling issue (like paediatriction/pediatriction or encylopaedia/encyclopedia)
    - ncmncm 7y ago
      If you care what sort of ether you're on about, you say "luminiferous ether".
  - chrisco255 7y ago
    Yeah but that was in an age before clickbait and "In this house, we believe science is real" yard signs. People are too bought into science as a source for truth instead of being a messy, difficult method of discovery.
dfischer 7y ago
As a frequent listener of cosmologists I'd say they regularly frame answers as dark energy were true.
awb 7y ago
> Is he implying that other cosmologists have proceeded as if dark energy is well evidenced? I thought dark matter and dark energy are simply placeholders for a discrepancy we see between our models of the universe and our observations. No?
- unlinked_dll 7y ago
  it's my understanding that dark matter is another word for the indirect observation of matter that we can't otherwise detect, through gravity. I don't know if calling it a placeholder is the proper parlance. Dark energy is something predicted by general relativity and iirc it's what is behind the expansion of space (and acceleration of expansion).
  - pdonis 7y ago
    > Dark energy is something predicted by general relativity Not really. GR can accommodate it just fine, but GR did not predict it. In fact, Einstein, who originally introduced the cosmological constant (which was the term then for what we now call "dark energy") in order to allow a static solution to his equation, thereby missed the chance to predict that the universe was expanding, a decade before Hubble's observations showed that it was. Once it became clear that expanding models matched the data, and did not (then) require a cosmological constant to do so, Einstein dropped it, calling it "the biggest blunder of my life". Only in the 1990s, when evidence for accelerating expansion became available, was the cosmological constant (now called "dark energy") put back into the equations so they would match the data. > it's what is behind the expansion of space (and acceleration of expansion) The expansion itself, no. The acceleration, yes.
    - galangalalgol 7y ago
      How much would the fate of the universe page on Wikipedia change with linear expansion? Do we have a bit longer before the stretch?
      - pdonis 7y ago
K0SM0S 7y ago
The question is moot: it's precisely because we have evidence of things not currently explained (observation does not fit theory) that we must postulate that our theory is wrong, or that there is more to discover, or both. "Dark energy" is a conventional term to describe some energy of unknown source that has the effect of accelerating space expansion with time. We call "dark energy" the thing that explains this observation, whatever that thing might be (we just assume it's some form of energy since it produces motion, acceleration, in a way seemingly opposed to, and stronger than gravity, but for all we knew it could be fluffy creatures from the 7th dimension, "energy" is just an educated guess). If you remove the observational discrepancy, then you remove the need for "dark energy" to exist in the first place. The article precisely suggests that: - there was no such observational discrepancy, rather errors in calculations following observation - reality is thus shown to conform to our current equations; it's our interpretation of the pretty pictures we took that was wrong all along; this is now corrected. If true, it's the end of dark energy as a cause because the consequence is gone. At no point (before or after it's proven or disproven) does "dark energy" imply a postulate on "what it actually is" — and chances are, when we explain previously unknown phenomena, the finders come up with a new theory and ad hoc terminology. Rarely the word sticks when it's just too good an intuition — e.g. the "atom". Note that "dark matter" is exactly the same, it's a conventional term to denote some matter-like unknown object that has the effect of giving galaxies their characteristic shapes and interactions forming much larger patterns (structure about as big to individual galaxies as galaxies are to individual stars).

AnimalMuppet 7y ago

It is my impression that dark energy is generally accepted in cosmology. Whether that counts as "proceeding as if dark energy is well evidenced" is perhaps a different question. If everyone believes it's there, but nobody knows what it is, well... there was still something that convinced them that it was there. That something should be evidence. Is it enough to count as "well evidenced"? Perhaps not, especially if this new study is correct that one piece of the evidence does not actually support dark energy.

ncmncm 7y ago
I don't know of any other evidence for dark energy, other than that mathematical physicists think the equations would be prettier with some, although they sort of wish there was more. It is quite embarrassing that the value was so close to zero without being zero, so that might be one embarrassment less. We already knew there was likely to be something fishy about the most distant supernovas, because we have two divergent values for the Hubble constant, one of them based on these same supernovas.
- AnimalMuppet 7y ago
  Hmm. Is this new result in the right direction to solve the Hubble Constant problem?
  - ncmncm 7y ago
    Haha, it would be fun if we now have three Hubble constants.
    - mindcrime 7y ago
      https://xkcd.com/927/ https://xkcd.com/927/
    - trhway 7y ago
      my personal favorite value for the Hubble constant is the "c" divided by the age of Universe, it results in 70.8 km/s/Mpc, right in the middle of the other 2 established Hubble constant's values, a very nice coincidence that the objects at the Universe age distance are running away exactly with "c".
      - AnimalMuppet 7y ago
        A coincidence? I think it might be an identity. But that would mean that disputes about the value of the Hubble Constant are also disputes about the age of the universe, and vice versa.
        ncmncm 7y ago
        Right, and that has been revised a few times recently.
- ailideex 7y ago
  > I don't know of any other evidence for dark energy, other than that mathematical physicists think the equations would be prettier with some, although they sort of wish there was more. https://en.wikipedia.org/wiki/Dark_energy#Evidence_of_existence https://en.wikipedia.org/wiki/Dark_energy#Evidence_of_existe...
StanislavPetrov 7y ago
>If everyone believes it's there, but nobody knows what it is, well... there was still something that convinced them that it was there. The article stipulates what convinced these people that it was there, namely that they rested their conclusions on an assumption that turned out to be wrong. This result is based on the assumption that the corrected luminosity of SN Ia through the empirical standardization would not evolve with redshift. Which is another good reason not to make conclusive judgements based on unproven assumptions (not that everyone that "dark energy" must exist, but many did, and some people still cling to it even if the face of this study). It is also a good example of why one should never give credence to a theory or a supposition based on how many other people give it credence - stick to what you can prove.

carbocation 7y ago

This doesn't really address your point, but the 2011 physics Nobel [1] said that "What is known is that dark energy constitutes about three quarters of the Universe." Not saying the Nobel write-ups constitute evidence, but dark energy has certainly been popular, at least. 1 = https://www.nobelprize.org/prizes/physics/2011/press-release/ https://www.nobelprize.org/prizes/physics/2011/press-release...

doodliego 7y ago
The Luminiferous Aether was popular too.
- stefantalpalaru 7y ago
  > The Luminiferous Aether was popular too. It still is: https://en.wikipedia.org/wiki/Quantum_field_theory https://en.wikipedia.org/wiki/Quantum_field_theory

phkahler 7y ago

>> Is he implying that other cosmologists have proceeded as if dark energy is well evidenced? As a non-cosmologist just reading HN I would say yes. Not quite as extensively as Dark matter though. I personally think that's a mistake too based on my limited research on the topic. If these are both overturned it will be a huge blow to "scientists" credibility in the eyes of the public. That's how invested they are.

coliveira 7y ago
> If these are both overturned it will be a huge blow to "scientists" credibility This is nonsense. Scientists have been wrong in several occasions, it is just part of the profession. For example, in the years leading to the discovery of relativity, many physicists believed there was something called "ether" that worked to fix the speed of light that they had evidence to be the same in all directions.
- deleted 7y ago
  [deleted]
- ShorsHammer 7y ago
  Generally called aether, believe that ether is a misspelling which has lingered. https://en.wikipedia.org/wiki/Aether_theories https://en.wikipedia.org/wiki/Aether_theories
  - mishac 7y ago
    I believe it's just a regional spelling issue (like paediatriction/pediatriction or encylopaedia/encyclopedia)
  - ncmncm 7y ago
    If you care what sort of ether you're on about, you say "luminiferous ether".
- chrisco255 7y ago
  Yeah but that was in an age before clickbait and "In this house, we believe science is real" yard signs. People are too bought into science as a source for truth instead of being a messy, difficult method of discovery.

dfischer 7y ago

As a frequent listener of cosmologists I'd say they regularly frame answers as dark energy were true.

awb 7y ago

> Is he implying that other cosmologists have proceeded as if dark energy is well evidenced? I thought dark matter and dark energy are simply placeholders for a discrepancy we see between our models of the universe and our observations. No?

unlinked_dll 7y ago
it's my understanding that dark matter is another word for the indirect observation of matter that we can't otherwise detect, through gravity. I don't know if calling it a placeholder is the proper parlance. Dark energy is something predicted by general relativity and iirc it's what is behind the expansion of space (and acceleration of expansion).
- pdonis 7y ago
  > Dark energy is something predicted by general relativity Not really. GR can accommodate it just fine, but GR did not predict it. In fact, Einstein, who originally introduced the cosmological constant (which was the term then for what we now call "dark energy") in order to allow a static solution to his equation, thereby missed the chance to predict that the universe was expanding, a decade before Hubble's observations showed that it was. Once it became clear that expanding models matched the data, and did not (then) require a cosmological constant to do so, Einstein dropped it, calling it "the biggest blunder of my life". Only in the 1990s, when evidence for accelerating expansion became available, was the cosmological constant (now called "dark energy") put back into the equations so they would match the data. > it's what is behind the expansion of space (and acceleration of expansion) The expansion itself, no. The acceleration, yes.
  - galangalalgol 7y ago
    How much would the fate of the universe page on Wikipedia change with linear expansion? Do we have a bit longer before the stretch?
    - pdonis 7y ago

K0SM0S 7y ago

The question is moot: it's precisely because we have evidence of things not currently explained (observation does not fit theory) that we must postulate that our theory is wrong, or that there is more to discover, or both. "Dark energy" is a conventional term to describe some energy of unknown source that has the effect of accelerating space expansion with time. We call "dark energy" the thing that explains this observation, whatever that thing might be (we just assume it's some form of energy since it produces motion, acceleration, in a way seemingly opposed to, and stronger than gravity, but for all we knew it could be fluffy creatures from the 7th dimension, "energy" is just an educated guess). If you remove the observational discrepancy, then you remove the need for "dark energy" to exist in the first place. The article precisely suggests that: - there was no such observational discrepancy, rather errors in calculations following observation - reality is thus shown to conform to our current equations; it's our interpretation of the pretty pictures we took that was wrong all along; this is now corrected. If true, it's the end of dark energy as a cause because the consequence is gone. At no point (before or after it's proven or disproven) does "dark energy" imply a postulate on "what it actually is" — and chances are, when we explain previously unknown phenomena, the finders come up with a new theory and ad hoc terminology. Rarely the word sticks when it's just too good an intuition — e.g. the "atom". Note that "dark matter" is exactly the same, it's a conventional term to denote some matter-like unknown object that has the effect of giving galaxies their characteristic shapes and interactions forming much larger patterns (structure about as big to individual galaxies as galaxies are to individual stars).