Dark energy is an aether

Caltech cosmologist Sean M. Carroll writes:

Probably the biggest single misconception I come across in popular discussions of dark matter and dark energy is the accusation that these concepts are a return to the discredited idea of the aether. They are not -- in fact, they are precisely the opposite.

Back in the later years of the 19th century, physicists had put together an incredibly successful synthesis of electricity and magnetism, topped by the work of James Clerk Maxwell. They had managed to show that these two apparently distinct phenomena were different manifestations of a single underlying "electromagnetism." One of Maxwell's personal triumphs was to show that this new theory implied the existence of waves traveling at the speed of light -- indeed, these waves are light, not to mention radio waves and X-rays and the rest of the electromagnetic radiation spectrum.

The puzzle was that waves were supposed to represent oscillations in some underlying substance, like water waves on an ocean. If light was an electromagnetic wave, what was "waving"? The proposed answer was the aether, sometimes called the "luminiferous aether" to distinguish it from the classical element. This idea had a direct implication: that Maxwell's description of electromagnetism would be appropriate as long as we were at rest with respect to the aether, but that its predictions (for the speed of light, for example) would change as we moved through the aether. The hunt was to find experimental evidence for this idea, but attempts came up short.  The Michelson-Morley experiment, in particular, implied that the speed of light did not change as the Earth moved through space, in apparent contradiction with the aether idea.

So the aether was a theoretical idea that never found experimental support. In 1905 Einstein pointed out how to preserve the symmetries of Maxwell's equations without referring to aether at all, in the special theory of relativity, and the idea was relegated to the trash bin of scientific history.

Aether was a concept introduced by physicists for theoretical reasons, which died because its experimental predictions were ruled out by observation. Dark matter and dark energy are the opposite: they are concepts that theoretical physicists never wanted, but which are forced on us by the observations.

I do not agree with this. The main experimental prediction of the aether was that light has wave properties, and has the same properties everywhere.

Here is what Michelson concluded in his 1881 paper, The Relative Motion of the Earth and the Luminiferous Ether:

The result of the hypothesis of a stationary ether is thus shown to be incorrect, and the necessary conclusion follows that the hypothesis is erroneous.

This conclusion directly contradicts the explanation of the phenomenon of aberration which has been hitherto generally accepted, and which presupposes that the earth moves through the ether, the latter remaining at rest.

So only a particular aether hypothesis was negated. Lorentz later showed in 1895 that this conclusion was false, and that the experiment was consistent with an aether at rest. Lorentz himself said said in 1895, "It is not my intention to ... express assumptions about the nature of the aether."

Contrary to Carroll, the aether was not necessarily thought to have a “frame of rest” in the 1800s. See Maxwell's 1878 essay for a survey of aether theories.

Dark energy is the discovery that the ubiquitous and uniform aether has positive energy and negative pressure. We do not know that the energy has a role in the transmission of light, so there may be more than one aether. But it fits right in with the aethers that Maxwell wrote about.

Rejecting hidden variables

Even since about 1930, physicists have looked for hidden variable theories to replace quantum mechanics. These theories have always been soundly rejected on theoretical and experimental grounds. And physicists just cannot let got. Even today, most of the interpretations of quantum mechanics assume that the wave function is real, and hence that physical reality has a perfect mathematical representation.

No such assumption was necessary for the original Copenhagen interpretation. The wave function cannot be observed directly, but possibilities for it are inferred from previous observations. Those functions evolve according to the Schroedinger equation, and can be used to predict observables. Making another observation allows us to restrict the set of possibilities for that wave function.

Physicists seem to be split on whether measurement causes a wavefunction collapse. If it does, then they are split over whether the collapse is objective, or related to observer consciousness. If there is no collapse, then they are split over whether part of the wave function escapes to another world where parallel observers see different outcomes.

I say that these dilemmas are all nonsense, and that the core mistake is to assume that the universe has a faithful mathematical representation and that the wave function is real. It is better to assume that there is no such representation, that there are no hidden variables, that there the wave function is not real but just a reflection of our knowledge about previous observations.

Matt Leifer gives a modern explanation of why hidden variables don't work. He has his own peculiar terminology, says that these are the only acceptable views:

Many people who advocate a psi-epistemic view also adopt an anti-realist or neo-Copenhagen point of view on quantum theory in which the quantum state does not represent knowledge about some underlying reality, but rather it only represents knowledge about the consequences of measurements that we might make on the system. ...

As emphasized by Harrigan and Spekkens, a variant of the EPR argument favoured by Einstein shows that any psi-ontic hidden variable theory must be nonlocal.

So he says that maybe the wave function is real (psi-ontic) and there are some nonlocal hidden variables, or the wave function is subjective (psi-epistemic) and there is no underlying reality, as Bohr said:

There is no quantum world. There is only an abstract physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature…

Leifer cannot accept that, and insists on ontic states (where some math formula faithfully matches reality).

It seems to me that searching for psi-ontic states or for an underlying mathematical reality is just continuing to fall for the hidden variable fallacy. It is better to do quantum mechanics without any hidden variable assumption. Go ahead and assume that there is an underlying physical reality, but do not assume that it is faithfully represented by hidden variables. Observations have mathematical values, but not the physical reality.

Free will theorem

There have been some recent books on free will, such as Free Will by Sam Harris and Who's in Charge?: Free Will and the Science of the Brain by Michael S. Gazzaniga. These books give anecdotes and opinions about the neuroscience of free will. These books do not live up to their promise, and do not give us any scientific evidence for who is in charge. There are also atheists and others who argue that we do not have free will because we are controlled by the unconscious mind. I believe that these views have no merit.

I say that free will is not a scientific issue.

I have criticized Free will in the multiverse.

On the physics side, the Free will theorem claims that human free will is linked to quantum indeterminism.

The theorem states that, given the axioms, if the two experimenters in question are free to make choices about what measurements to take, then the results of the measurements cannot be determined by anything previous to the experiments.

I don't see how this theorem says anything about free will. The theorem has three plausible sounding axioms, but it also assumes a deterministic model for producing photon pairs. According to the model, the photon seem to have some random aspects that observers can see if they are allowed to make their own random choices. So the theorem shows that the models are really indeterministic.

This is all just a fancy way of saying that there are quantum experiments that look random. This doesn't mean much as coin tosses look random also, but could be deterministic if you knew more about the coin.

Coyne says freedom was killed by science

Leftist-atheist-evolutionist Jerry Coyne hates religion, and denies religious claims that we can make decisions about our lives. His current rant says:

What is important to me is whether our decisions are predetermined (with perhaps a dollop of quantum indeterminacy), and therefore we lose our freedom to really make different choices when given alternatives. The old notion of true freedom — the ability to do otherwise — has been killed dead by science. Why are people trying to save the notion of free will by confecting other definitions? Why aren’t they, instead, telling the faithful that they can’t really choose whether to be saved or make Jesus their personal saviour? The faithful are dualists, and religion is our enemy.

This is ridiculous. He likes to lecture us on what science is all about, but he gets it badly wrong. His rant was triggered by atheist-physicist Victor Stenger, who writes:

Research in neuroscience has revealed a startling fact that revolutionizes much of what we humans have previously taken for granted about our interactions with the world outside our heads: Our consciousness is really not in charge of our behavior.

I have criticized Coyne and others on free will here, here, and here. I say that free will is not a scientific issue.

If science really proved these things, ask yourself: Where is the published paper? Who got the Nobel Prize? These scientists are an embarrassment to science.

The "dollop of quantum indeterminacy" is especially strange. Stenger argues:

The moving parts of the brain are heavy by microscopic standards and move around at relatively high speeds because the brain is hot. Furthermore, the distances involved are large by these same microscopic standards. It is easy to demonstrate quantitatively that quantum effects in the brain are not significant. So, even though libertarians are correct that determinism is false at the microphysical, quantum level, the brain is for all practical purposes a deterministic Newtonian machine, so we don't have free will as they define it.

This argument is frequently made, but I do not believe it. There are chemical reactions in the brain, and quantum effects are essential for all such reactions. So I do not know how anyone can say that quantum effects are insignificant. And even if that were true, it does not follow that the brain is a deterministic Newtonian machine. No one has succeeded in predicting brain behavior, except in trivial ways.

Update: I agree with this podcast today by Pigliucci and Churchland (at about 50:00) that it is stupid to say that "free speech is an illusion", as Coyne, Stenger, and Sam Harris say. Yes, it is an illusion in the trivial sense that a table is an illusion. If "illusion" means that there is a materialist explanation in terms of smaller components, then it is an illusion. But if it is an attempt to deny that we can evaluate consequences and make decisions, then they are manifestly wrong. They are denying the facts and presenting an anti-science view of the world.

Massimo Pigliucci responds:

Roger, your comment reflects the attitude of people like Harris, Coyne, Rosenberg et al., but I think is too quick. First, science cannot disprove an incoherent concept like contra-causal free will. Indeed, philosophy can do that (because it's a matter of logic). Second, this whole thing has very little to do with religion, because religionists believe in contra-causal free will, which is not the target of this research. Third, there is a danger in uncritically accepting Harris-like sweeping statements about human volition, and that danger is that we throw out human agency, ethics, and pretty much everything that makes us human, quickly leading nihilism (which in fact Rosenberg at least openly embraces).

Explained by local deterministic processes

The 2010 Wolf Prize in Physics citation says:

The puzzling properties of entangled quantum states, first noted by Einstein, Podolsky and Rosen, who suspected that quantum mechanics is not a complete theory, were dramatically delineated by the remarkable work of John Bell. Bell showed that certain statistical correlations between properties of two physically separated particles, which were produced in an entangled quantum state, cannot be explained by any theory of local deterministic processes even if other unobserved properties (‘hidden variables') are allowed for.

None of this is correct. Entanglement was part of quantum mechanics before the 1935 EPR paper. Einstein got it from Popper's 1934 experiment. EPR was about uncertainty principle and completeness, not spin and determinism. More importantly, Bell's theorem only shows that quantum mechanics differs from certain local hidden variable theories. It says nothing about local deterministic processes.

The Wolf statement is like saying, "relativity experiments like Michelson-Morley show that light cannot be explained by any theory of space and time, even if the aether is allowed for. Well, no. Relativity explains Michelson-Morley and quantum mechanics explains spin entanglement.

Relativity does require some adjustments to your preconceptions about space and time, and quantum mechanics requires some adjustments to your preconceptions about hidden variables. If you refuse to make those adjustments, and insist on making your own assumptions, then sure, you will get some contradictions. That is what Bell and those Wolf Prize winners discovered. But they did not discover any experiments that cannot be explained by local deterministic processes.

Freud fled the Nazis

My post below mentioned Freud, and I discovered a huge section was removed from the Wikipedia article:

There is a growing body of literature that points to the ongoing legacy of Freud’s work for understandings of questions of race and cultural difference, as well as for understandings of the political frameworks through which these questions of difference are addressed. The ways in which both psychoanalysis and Freud himself were persecuted as Jewish by Nazis and their collaborators have been well documented. As Karen Brecht and others have pointed out, “During the 1930s, while there were about 56 members of the German Psychoanalytic Society (Deutsche Psychoanalytische Gesellschaft, DPG); only nine were German ‘Aryans.’ ... Most of Germany’s Jewish psychoanalysts fled from Germany and Nazi-occupied Europe in the early 1930s; ...

While Freud himself defined psychoanalysis in universalist terms, a number of scholars have argued that psychoanalysis can nonetheless be understood as a Jewish science. Sander Gilman has argued that psychoanalysis can be understood as a Jewish science not simply because many of its founders were themselves Jewish and because psychoanalysis was attacked as a Jewish science, but because Freud’s development of psychoanalysis was itself informed by the ways in which Jews were pathologized. He argues that Freud made the Jew invisible in psychoanalysis in response to the ways in which Jews were pathologized, and that “the new science of psychoanalysis provided status for the Jew as scientist while re-forming the idea of medical science to exclude the debate about the implication of race.”

I don't get why this is so controversial. It appears to be well-sourced and not any more controversial that a lot of other Freud opinions.

No scientific model for some problems

SciAm writer John Horgan writes Why B. F. Skinner, Like Freud, Still Isn’t Dead:

Note what Chomsky is saying: that neither behaviorism nor any other scientific model can explain — or is even close to explaining — how humans learn language, which is arguably our defining trait. (In spite of his own emphasis on the genetic underpinnings of language, Chomsky has been cruelly dismissive of evolutionary psychology, which he once called a “philosophy of mind with a little bit of science thrown in.”)

In a recent column on philosopher of science Thomas Kuhn, I pointed out that some fields, especially “hard” ones like physics and chemistry, converge on a paradigm and rapidly progress, while others “remain in a state of constant flux.” Fields that address human thought and behavior—anthropology, economics, sociology, political science, psychology – are prime example of research endeavors that lurch faddishly from one paradigm to another.

Will psychologists ever find a paradigm powerful enough to unify the field and help it achieve the rigor of, say, nuclear physics or molecular biology? William James had his doubts. More than a century ago he fretted that psychology might never transcend its “confused and imperfect state.” Harvard psychologist Howard Gardner has argued that James’s concerns “have proved all too justified. Psychology has not added up to an integrated science, and it is unlikely ever to achieve that status.” Gardner once told me that questions about free will, the self, consciousness and other topics with which psychologists (and, tellingly, philosophers) wrestle might not be amenable to conventional scientific reductionism, in spite of all the advances of modern genetics, neuroscience and brain imaging.

So Skinner and Freud continue to be idolized, long after they have been discredited, because of low standards in the field of psychology.

I am told that Chomsky's views are in the minority, even tho everyone agrees that they were brilliant.

I believe that even the hard sciences have problems that are not solved by any scientific model, and they will never be. Free will is one. Physicists have lots of opinions about what is deterministic or probabilistic, but those opinions have no scientific basis.