Etzel Cardeña has published an extensive review of parapsychology concluding that it is both plausible and supported by evidence. It stands, in my opinion, as an excellent example of everything that is wrong with psi research. There is a lot of meat to go through, but I want to focus in this article on his use of quantum mechanics to justify the plausibility of ESP and psi phenomena.

Psi, or anomalous cognition, is a group of alleged phenomena that include sensing what other people are thinking, viewing remote locations not accessible to the normal senses, and predicting the future in some way. These claims are inherently implausible because there is no way to account for them with known phenomena. They appear, therefore, to violate well-established laws of physics. Therefore, any reasonable scientists would argue, the threshold of evidence needed before concluding that a psi phenomenon is real should be very high. What we have is very low-grade evidence at best, therefore it is reasonable to reject claims for psi.

Psi proponents, therefore, attack the two pillars of this rejection – that psi is implausible, and that the evidence is low-grade. Cardeña is no exception, and that is precisely what he is trying to do in his paper. He fails on both counts, producing only a string of cherry-picked evidence, selected quotes that can be made to seem as if they support his position, and very strained logic.

What do we mean by plausibility? This is actually a deceptively complex question. Plausibility essentially means, if we had to guess, based on everything we know so far about the universe, is a specific claim likely to be true? There is a very broad range of plausibility, and unfortunately often people refer to plausibility as a false dichotomy, that a claim is either plausible or not. This dichotomy obscures a vast spectrum, which matters because we deal with different locations on that spectrum very differently.

For example, in medicine scientists may extrapolate from current knowledge of physiology to predict that binding a certain receptor will have a specific net clinical effect. Those predictions then determine how plausible they think it is that a drug binding to that receptor will have a desired effect, such as mitigating a symptom or treating a disease. This is important if you are a pharmaceutical company deciding whether or not to spend tens of millions of dollars on research. But really, this is all at the very plausible end of the spectrum. Extrapolating to net clinical effects is very hard – the fact that a drug gets into the system and binds to a receptor that has some known physiological effects is well within the range of reasonable plausibility.

At the other end of the spectrum are claims that literally break the laws of physics. Any claim that a device produces free energy, for example, should be met with extreme skepticism. You cannot treat such claims the same way you treat claims made for a drug affecting a complex physiological system in the body. In fact using the same term “implausible” for both types of claims is problematic, producing a false equivalency that generates confusion.

It is important to note that at the extreme implausible end of the spectrum, into “breaking the laws of physics” territory, extreme skepticism is warranted. This does not mean “impossible” because scientific knowledge is always finite, but it would take a scientific home-run to send physicists scrambling to account for the results. And scramble they would – because experimental results that cannot be explained based on known physics is what physicists live for. Such results point the way to new physics.

Nonlocality

Cardeña takes a typical proponent’s approach to the implausibility problem of psi, recycling long discredited arguments from quantum mechanics. He does not address the criticisms that have already been leveled at this position, and mostly selectively quotes from scientists that seem to support his position. He begins with a discussion of nonlocality, the notion that the universe is constructed in such a way that everything is interconnected, even at great distances.

He uses the typical argument, that of quantum entanglement. If two particles emerge from one system, they will display entangled properties. This is because of conservation laws – you cannot produce energy, charge, or momentum from nothing. So if one particle, for example, is spin up, the other has to be spin down, so that the spins cancel each other out, producing no net spin, and no violation of conservation laws.

However, at the quantum level particles display what we call superposition. They are particles and waves at the same time, and may have other properties that have not yet declared themselves but exist in a superposition. So, those two particles may both be in a superposition of both spin up and down. However, if one particle interacts with its environment it must do so with specific properties. The superpositions then collapse into a specific particle with specific properties. The particle, therefore, may go from a superposition of spin up and spin down to being just spin up. At that same instant, the other particle must then become spin down. That is what is meant by entangled.

The problem for physicists is that the two particles will display these entangled properties even if they have been separated by trillions of kilometers distance and many years. They seem to communicate to each other instantly over vast distances. This is what is meant by nonlocality – they are behaving not as if they exist in distant local environments, but as if they exist in one interconnected environment. This is a “problem” because this appears to violate principles of relativity, such as communication at faster than light speed. This is what Einstein decried as “spooky action at a distance.”

But there are significant problems with using experiments that show such quantum entanglement to argue that psi is plausible, as Cardeña does. Perhaps most significantly, such entanglement only occurs is very fragile and specific environments. In order to produce entanglement experimentally, researchers typically need to create extremely isolated and cold systems.

The reason for this is that any interaction with matter or energy in the environment causes what is known as decoherence – the particles’ superposition collapses and the entanglement is gone. Decoherence means that in everyday macroscopic objects, like your brain, there are no non-local effects. Your brain is not entangled with anyone else’s brain, not even a little bit.

Further, there is something known as the de Broglie’s limit, which is a measure of the quantum wavelength of objects. The wavelength is inversely proportional to size, and for macroscopic objects the wavelength is tiny – smaller than primary particles, getting down to a Planck length. In other words – it is insignificantly small, so that it can be treated as zero.

Also devastating to the claims of Cardeña is that fact that, despite fragile and extreme experimental setups to create quantum entanglement, such systems cannot be used to transfer information. By information that means – nothing, no physical effects (other than the entangled properties themselves). Since those intangled properties seem to collapse randomly, no information is communicated. Relativity states that no information can travel faster than the speed of light in a vacuum, and quantum entanglement obeys relativity in that respect.

Since psi phenomena are all about transferring information, it is therefore hard to see how any of this supports psi. In fact, if anything, it adds to the conclusion that psi is implausible. Cardeña addresses none of this, but simply quotes others making the giant leap that because exquisitely controlled quantum systems can be made to show entanglement, that the entire universe is nonlocal and interconnected, therefore psi is plausible. This position is still utter nonsense.

Time

What about experiments that allege to show the future affecting current behavior? Cardeña writes:

Einstein’s theories of time and the ensuing experiments demonstrated that objectively measured time and space are not absolute and depend on such variables as the position and speed of the observers and the gravitational field. For instance, events that are still in the future of a slow-moving individual may have already occurred to a faster moving one; furthermore, in the special relativity block universe theory of time, past, present, and future coexist simultaneously although we experience only the present (Davies, 2002).

Cardeña again shows he does not truly understand quantum mechanics or relativity. That’s OK, most people don’t. But you shouldn’t use scientific theories you don’t understand.

Yes, time is variable. That was a great insight of Einstein. But relativity simultaneously holds that information cannot go back in time, nor can it travel faster than light. One person may seem to experience an event faster than another, depending on frame of reference, but the person who seems to experience the event first cannot communicate their experience to the other person before that person experiences the event. This is not an end-run around the arrow of time. Sorry.

Cardeña also is fond of citing theories which are convenient for arguing that psi is plausible. But – referencing an unproven theory, especially one that is highly speculative, does not render your theory plausible. You can’t use one speculation to support another as if it were a solid premise.

Psi is still implausible

The problem with psi proponents like Cardeña is that they appear desperate to premataurely declare victory. This is a common feature of pseudoscience, and it leads one to try to prove their theory true. Rather, a good scientist should be trying to prove their theory wrong. They should be their own harshest skeptics, and only theories that survive this harsh skepticism should be considered tentatively supported.

Trying to support psi with appeals to quantum mechanics and relatively ultimately is a giant argument from ignorance. What is solid and known about quantum mechanics, like entanglement, do not in any way support psi. Again, as I said, if anything they are further evidence against it. What Cardeña has to do is not use what is experimentally known about quantum mechanics, but rather wild speculation about the implications of what is known about quantum mechanics. Further, he uses highly cherry-picked wild speculation, and then declares psi plausible.

This does not work, and nor does psi.