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I guess people are going to act like I'm a lunatic, but of course it's wrong. Dark Energy violates basic conservation of energy, and the evidence for it has ne

I guess people are going to act like I'm a lunatic, but of course it's wrong. Dark Energy violates basic conservation of energy, and the evidence for it has never been strong or convincing. Lots of us have been saying this since forever.

ncmncm 7y ago
Conservation of energy has only ever been observed in local conditions. The universe is not obliged to respect our local expectations, and has always turned out to violate them in uncomfortable ways. The ground looks flat near you (at least in Nebraska). The Sun seems to go around Earth.
- ltbarcly3 7y ago
  Which is more likely, that you can have infinite free energy or that the very careful measurements of the distances to supernova that happened billions of years ago on the other side of the universe, and for which we have virtually no standard yardstick to compare against are not accurate? You are just making an appeal to ignorance. All of physics and astronomy is based on the assumption that the rest of the universe follows the same basic laws that the part we can study follows. That the universe is isotropic and homogeneous is a necessary basic assumption to even begin to measure the distance to objects that are very far away. If you can't assume that the basic laws of physics operate the same everywhere, then you have no basis to make any claims about anything that isn't local.
  - ncmncm 7y ago
    That is the condition of cosmology. Not everyone envies it.
    - ltbarcly3 7y ago
      It's an assumption, and while you might make a reasonable argument to try to justify it, it's still an assumption. The real problem is when we cross from 'assuming these things, which we don't really have a strong reason to assume' to 'this is the way the universe is'. Without the qualifications it's extremely misleading and loses any basis it started with.
      - ncmncm 7y ago
        Conservation of energy can never be more than a collection of observations. Elevate it to a principle, and you're not doing science anymore, you're doing religion. But not a fun one.
        ltbarcly3 7y ago
        All of science is just a collection of observations combined with attempts to find patterns in those observations. Read up on Hume, Inductive Reasoning. There is no fundamental grounding for the idea that what any of the rules we observe the universe following won't change suddenly for no reason apart from the fact that we have never seen it happen.
        ncmncm 7y ago
        Inductive reasoning works reliably in mathematics and formal logic, and literally nowhere else. So, if you have a mathematical model of physics, you can use inductive reasoning on that model, but the universe is under no obligation to obey your model. In fact, we have found our models to be violated by nature over and over, countless thousands of times. Quantum field theory and General Relativity arose specifically to address exactly such violations of older models. Nobody has found violations of either (unless it finally turns out there isn't actually dark matter). Dark energy and its lack happen to be both consistent with GR. GR and QFT are not consistent with one another, so one or both will need to give, but each has thus far passed every actual test. You may insist that red shift is not caused by universal expansion, but then you need another explanation for it, consistent with observations. Discomfort is not such an explanation. Your religion is not fun.
        ltbarcly3 7y ago
        Despite the wonderfully dismissive tone of your post, it seems like you don't know what the term 'inductive reasoning' means. > Inductive reasoning works reliably in mathematics Mathematics does not use inductive reasoning. Inductive reasoning is not logically valid. Perhaps you have confused 'inductive reasoning' with 'the method of induction'. While there are some shared root words they are not related concepts. 'The method of induction' uses deductive reasoning, as does every mathematical proof. There are no exceptions to this, see: https://plato.stanford.edu/entries/mathematics-nondeductive/ https://plato.stanford.edu/entries/mathematics-nondeductive/ . Mathematicians might look at examples or write computer programs to explore a problem, but when it comes time to write a proof there is no such thing as a non-deductive proof. > In fact, we have found our models to be violated by nature over and over, This doesn't even disagree with anything I have said. > You may insist that red shift is not caused by universal expansion I'm not insisting that red shift is not caused by universal expansion. I'm insisting that expansion, if it exists, violates the conservation of energy. The conservation of energy is extremely well established in that we can't find exceptions to it locally. Meanwhile expansion is extremely hard to study, and relies on connecting long chains of measurements for which we cannot reliably estimate the accuracy of. I simply think that it is more likely, as a matter of prognostication, that it will turn out the distance ladder has significant corrections or that one of the basic assumptions underlining expansion (for example that the universe is homogeneous or isotropic outside of the visible universe) ends up being overturned.
  - cthalupa 7y ago
    This is a false dichotomy. We have known energy is not (always) conserved since long before we began discussing dark energy. This is such a misunderstood topic vis a vis dark energy that Discovery specifically has an article on it: https://www.discovermagazine.com/the-sciences/energy-is-not-conserved https://www.discovermagazine.com/the-sciences/energy-is-not-...
    - ltbarcly3 7y ago
      Nope. We have no actual evidence of a violation of the conservation of energy. What has happened here is that astrophysicists got way out on a branch. They were quite excited and came up with a theory that seemed to explain why there appeared to be increasing redshift with distance, and later that theory was shown to violate conservation of energy. Doubling down, they waved their hands and said that conservation of energy must not hold at 'cosmological scales', without any evidence to make such a claim.
      - mr_mitm 7y ago
        Please read this and let me know if you are still convinced that energy must be conserved in General Relativity: https://www.preposterousuniverse.com/blog/2010/02/22/energy-is-not-conserved/ https://www.preposterousuniverse.com/blog/2010/02/22/energy-... (edit: Nevermind, this is the same content as the Discovery article linked above, except with better formatting). In short: conservation of energy is a result from the Noether theorem, which says it must be conserved iff the laws of physics are invariant under time translations. That's the case in Newtonian physics where we also have plenty of experiments supporting it, but not in GR. Precisely because of the expansion of the universe, the metric is time dependent and thus there can not be an associated conserved quantity. This has been known before we knew about dark energy or even the expansion of the universe.
        ltbarcly3 7y ago
        You are using circular reasoning. Energy is not conserved if the universe is expanding. I am saying of course that isn't happening, the evidence for expansion is poor and now has been shown to be unreliable. Without expansion energy is conserved. The example from your article is expansion, which it assumes to be a fact based on the poor evidence that is now invalidated.
lokedhs 7y ago
Conservation of energy only applies to closed systems though. And an expanding universe (with or without dark energy) is not a closed system.
ben509 7y ago
Things are conserved when there's a corresponding symmetry; this is Noether's Theorem.[1] I won't pretend to understand half that article, but here's a video[2] on it. [1]: https://en.wikipedia.org/wiki/Noether%27s_theorem https://en.wikipedia.org/wiki/Noether%27s_theorem [2]: https://www.youtube.com/watch?v=04ERSb06dOg https://www.youtube.com/watch?v=04ERSb06dOg

ncmncm 7y ago

Conservation of energy has only ever been observed in local conditions. The universe is not obliged to respect our local expectations, and has always turned out to violate them in uncomfortable ways. The ground looks flat near you (at least in Nebraska). The Sun seems to go around Earth.

ltbarcly3 7y ago
Which is more likely, that you can have infinite free energy or that the very careful measurements of the distances to supernova that happened billions of years ago on the other side of the universe, and for which we have virtually no standard yardstick to compare against are not accurate? You are just making an appeal to ignorance. All of physics and astronomy is based on the assumption that the rest of the universe follows the same basic laws that the part we can study follows. That the universe is isotropic and homogeneous is a necessary basic assumption to even begin to measure the distance to objects that are very far away. If you can't assume that the basic laws of physics operate the same everywhere, then you have no basis to make any claims about anything that isn't local.
- ncmncm 7y ago
  That is the condition of cosmology. Not everyone envies it.
  - ltbarcly3 7y ago
    It's an assumption, and while you might make a reasonable argument to try to justify it, it's still an assumption. The real problem is when we cross from 'assuming these things, which we don't really have a strong reason to assume' to 'this is the way the universe is'. Without the qualifications it's extremely misleading and loses any basis it started with.
    - ncmncm 7y ago
      Conservation of energy can never be more than a collection of observations. Elevate it to a principle, and you're not doing science anymore, you're doing religion. But not a fun one.
      - ltbarcly3 7y ago
        All of science is just a collection of observations combined with attempts to find patterns in those observations. Read up on Hume, Inductive Reasoning. There is no fundamental grounding for the idea that what any of the rules we observe the universe following won't change suddenly for no reason apart from the fact that we have never seen it happen.
        ncmncm 7y ago
        Inductive reasoning works reliably in mathematics and formal logic, and literally nowhere else. So, if you have a mathematical model of physics, you can use inductive reasoning on that model, but the universe is under no obligation to obey your model. In fact, we have found our models to be violated by nature over and over, countless thousands of times. Quantum field theory and General Relativity arose specifically to address exactly such violations of older models. Nobody has found violations of either (unless it finally turns out there isn't actually dark matter). Dark energy and its lack happen to be both consistent with GR. GR and QFT are not consistent with one another, so one or both will need to give, but each has thus far passed every actual test. You may insist that red shift is not caused by universal expansion, but then you need another explanation for it, consistent with observations. Discomfort is not such an explanation. Your religion is not fun.
        ltbarcly3 7y ago
        Despite the wonderfully dismissive tone of your post, it seems like you don't know what the term 'inductive reasoning' means. > Inductive reasoning works reliably in mathematics Mathematics does not use inductive reasoning. Inductive reasoning is not logically valid. Perhaps you have confused 'inductive reasoning' with 'the method of induction'. While there are some shared root words they are not related concepts. 'The method of induction' uses deductive reasoning, as does every mathematical proof. There are no exceptions to this, see: https://plato.stanford.edu/entries/mathematics-nondeductive/ https://plato.stanford.edu/entries/mathematics-nondeductive/ . Mathematicians might look at examples or write computer programs to explore a problem, but when it comes time to write a proof there is no such thing as a non-deductive proof. > In fact, we have found our models to be violated by nature over and over, This doesn't even disagree with anything I have said. > You may insist that red shift is not caused by universal expansion I'm not insisting that red shift is not caused by universal expansion. I'm insisting that expansion, if it exists, violates the conservation of energy. The conservation of energy is extremely well established in that we can't find exceptions to it locally. Meanwhile expansion is extremely hard to study, and relies on connecting long chains of measurements for which we cannot reliably estimate the accuracy of. I simply think that it is more likely, as a matter of prognostication, that it will turn out the distance ladder has significant corrections or that one of the basic assumptions underlining expansion (for example that the universe is homogeneous or isotropic outside of the visible universe) ends up being overturned.
- cthalupa 7y ago
  This is a false dichotomy. We have known energy is not (always) conserved since long before we began discussing dark energy. This is such a misunderstood topic vis a vis dark energy that Discovery specifically has an article on it: https://www.discovermagazine.com/the-sciences/energy-is-not-conserved https://www.discovermagazine.com/the-sciences/energy-is-not-...
  - ltbarcly3 7y ago
    Nope. We have no actual evidence of a violation of the conservation of energy. What has happened here is that astrophysicists got way out on a branch. They were quite excited and came up with a theory that seemed to explain why there appeared to be increasing redshift with distance, and later that theory was shown to violate conservation of energy. Doubling down, they waved their hands and said that conservation of energy must not hold at 'cosmological scales', without any evidence to make such a claim.
    - mr_mitm 7y ago
      Please read this and let me know if you are still convinced that energy must be conserved in General Relativity: https://www.preposterousuniverse.com/blog/2010/02/22/energy-is-not-conserved/ https://www.preposterousuniverse.com/blog/2010/02/22/energy-... (edit: Nevermind, this is the same content as the Discovery article linked above, except with better formatting). In short: conservation of energy is a result from the Noether theorem, which says it must be conserved iff the laws of physics are invariant under time translations. That's the case in Newtonian physics where we also have plenty of experiments supporting it, but not in GR. Precisely because of the expansion of the universe, the metric is time dependent and thus there can not be an associated conserved quantity. This has been known before we knew about dark energy or even the expansion of the universe.
      - ltbarcly3 7y ago
        You are using circular reasoning. Energy is not conserved if the universe is expanding. I am saying of course that isn't happening, the evidence for expansion is poor and now has been shown to be unreliable. Without expansion energy is conserved. The example from your article is expansion, which it assumes to be a fact based on the poor evidence that is now invalidated.

lokedhs 7y ago

Conservation of energy only applies to closed systems though. And an expanding universe (with or without dark energy) is not a closed system.

ben509 7y ago

Things are conserved when there's a corresponding symmetry; this is Noether's Theorem.[1] I won't pretend to understand half that article, but here's a video[2] on it. [1]: https://en.wikipedia.org/wiki/Noether%27s_theorem https://en.wikipedia.org/wiki/Noether%27s_theorem [2]: https://www.youtube.com/watch?v=04ERSb06dOg https://www.youtube.com/watch?v=04ERSb06dOg