Quantum Diaries

Recently it has been announce that a smoking gun has been found for cosmic inflation but could it instead be the smoking[1] gun for a grand conspiracy, the mother of all conspiracies, the conspiracy theory to put all other conspiracy theories to shame?  You may have your favourite conspiracy theory: the Roswell cover up, who shot JFK, the suppression of perpetual motion machines by the energy companies or the attempt by communication departments to take over the world. As a professor, once said: “Just because you are paranoid does not mean they are not out to get you.” (Followed closely by my second-best piece of advice, “Never trust a communications expert.”) But the conspiracy I am talking about is on a much larger scale, a cosmic scale, the conspiracy of all elementary particles in the universe to use their free will for the sole purpose of messing with the minds of humans and particularly that subclass of humans known as particle physicists[2]. The professor was right to be paranoid.

We hold these truths to be self-evident, that all particles are created equal and endowed by their Creator with free will. Surely you do not question that elementary particles have free will. Consider the muon. It decays at a time if its own choosing.  There is no rule that says when a given muon will decay. It is decided by the muon in its own stubborn way.  But you still claim that only humans have freewill. Why? Could it not be just of part the grand conspiracy of elementary particle to give humans the illusion of freewill? Besides we all know politicians do not have freewill. They just do, as a Pavlovian reflex, what they think will get them the most votes.  Hence the mess the world is in. But I digress.

To explore further: what criteria is there to decide if a given object has freewill? Is it just unpredictability? If so, then Vancouver weather has freewill. We have already decided that politicians do not have freewill. But what about dogs? Are all their reactions Pavlovian conditioning? Most certainly not.  Hence they are better candidates to have freewill than politicians. And what about cats? Cats certainly have will but it is free?  Does the fact cats cannot be herded indicate they have freewill? And cows, do cows have freewill? Does the fact they can be herded indicate they do not have freewill? Or that plant on my window sill beckoning to be watered?  Does it cause its leaves to droop out of the exercise of its own freewill just to annoy me? Possibly (there it goes again). It seems to me the hallmark of freewill is precisely that combination of random and non-random behaviour found in elementary particles and not in politicians. Hence another interpretations of quantum uncertainty, it is just elementary particles exercising their freewill.

You may be surprised that I claimed all particles are created equal. Surely the neutrino and electron have different properties and are not equal. But that is just them exercising their freewill. Those particles we call electrons have decided (note the verb decided) to behave as if they had a given set of interactions while the neutrinos have decided to be behave like they have a different set of interactions. The interactions, themselves, are illusionary created by the particles exercising their freewill. There was probably a grand council meeting at the beginning of time where the grand conspiracy was initiated and the roles assigned to different sets of particles.  Indeed, it may have been that grand council meeting that started time itself.

The freewill of particles also explains the problem of evil. From earthquakes to global warming[3], the evil consequences are due to particle exercising their freewill. This type of evil could only be eliminated by denying particles freewill­–an even greater evil.

Now back to the initial observation about the polarization of photons in the cosmic microwave background. Surely that polarization is not due to gravitational waves but due to photons exercising their freewill to mislead humans. Is it not more reasonable to assume that the measured polarization[4] is due to freewill than to some far distant interaction with gravitons? (Do gravitons even exits? They have never been directly observed.)

This conspiracy theory–just like all conspiracy theories–accounts for all the known facts and cannot be disproved. It therefore must be correct and we have shown conclusively that it is particles, not people, that have freewill and the photons are trying to mess with our minds[5].

To receive a notice of future posts follow me on Twitter: @musquod.

Despite the old canard about nobody understanding quantum mechanics, physicists do understand it.  With all of the interpretations ever conceived for quantum mechanics[1], this claim may seem a bit of a stretch, but like the proverbial ostrich with its head in the sand, many physicists prefer to claim they do not understand quantum mechanics, rather than just admit that it is what it is and move on.

What is it about quantum mechanics that generates so much controversy and even had Albert Einstein (1879 – 1955) refusing to accept it? There are three points about quantum mechanics that generate controversy. It is probabilistic, eschews realism, and is local. Let us look at these three points in more detail.

1. Quantum mechanics is probabilistic, not determinist. Consider a radioactive atom. It is impossible, within the confines of quantum mechanics, to predict when an individual atom will decay. There is no measurement or series of measurements that can be made on a given atom to allow me to predict when it will decay. I can calculate the probability of when it will decay or the time it takes half of a sample to decay but not the exact time a given atom will decay. This lack of ability to predict exact outcomes, but only probabilities, permeates all of quantum mechanics. No possible set of measurements on the initial state of a system allows one to predict precisely the result of all possible experiments on that state.
2. Quantum mechanics eschews realism[2]. This is a corollary of the first point. A quantum mechanical system does not have well defined values for properties that have not been directly measured. This has been compared to the moon only existing when someone is looking at it. For deterministic systems one can always safely infer back from a measurement what the system was like before the measurement. Hence if I measure a particle’s position and motion I can infer not only where it will go but where it has come from. The probabilistic nature of quantum mechanics prevents this backward looking inference. If I measure the spin of an atom, there is no certainty that is had only that value before the measurement. It is this aspect of quantum mechanics that most disturbs people, but quantum mechanics is what it is.
3. Quantum mechanics is local. To be precise, no action at point A will have an observable effect at point B that is instantaneous, or non-causal.  Note the word observable. Locality is often denied in an attempt to circumvent Point 2, but when restricted to what is observable, locality holds. Despite the Pentagon’s best efforts, no messages have been sent using quantum non-locality.

Realism, at least, is a common aspect of the macroscopic world. Even a baby quickly learns that the ball is behind the box even when he cannot see it. But much about the microscopic world is not obviously determinist, the weather in Vancouver for example (it is snowing as I write this). Nevertheless, we cling to determinism and realism like a child to his security blanket. It seems to me that determinism or realism, if they exist, would be at least as hard to understand as their lack. There is no theorem that states the universe should be deterministic and not probabilistic or vice versa. Perhaps god, contrary to Einstein’s assertion, does indeed like a good game of craps[3].

So quantum mechanics, at least at the surface level, has features many do not like. What has the response been? They have followed the example set by Philip Gosse (1810 – 1888) with the Omphalos hypothesis[4]. Gosse, being a literal Christian, had trouble with the geological evidence that the world was older than 6,000, so he came up with an interpretation of history that the world was created only 6,000 years ago but in such a manner that it appeared much older. This can be called an interpretation of history because it leaves all predictions for observations intact but changes the internal aspects of the model so that they match his preconceived ideas. To some extent, Tycho Brahe (1546 – 1601) used the same technique to keep the earth at the center of the universe. He had the earth fixed and the sun circle the earth and the other planets the sun. With the information available at the time, this was consistent with all observations.

The general technique is to adjust those aspects of the model that are not constrained by observation to make it conform to one’s ideas of how the universe should behave. In quantum mechanics these efforts are called interpretations. Hugh Everett (1930 – 1982) proposed many worlds in an attempt to make quantum mechanics deterministic and realistic. But it was only in the unobservable parts of the interpretation that this was achieved and the results of experiments in this world are still unpredictable. Louis de Broglie (1892 – 1987) and later David Bohm (1917 – 1992) introduced pilot waves in an effort to restore realism and determinism. In doing do they gave up locality. Like Gosse’s work, theirs was nice proof in principle that, with sufficient ingenuity, the universe could be made to conform to almost any preconceived ideas, or at least appear to do so. Reassuring I guess, but like Gosse it was done by introducing non-observable aspects to the model: not just unobserved but in principle unobservable. The observable aspects of the universe, at least as far as quantum mechanics is correct, are as stated in the three points above: probabilistic, nonrealistic and local.

Me, I am not convinced that there is anything to understand about quantum mechanics beyond the rules for its use given in standard quantum mechanics text books. However, interpretations of quantum mechanics might, possibly might, suggest different ways to tackle unsolved problems like quantum gravity and they do give one something to discuss after one has had a few beers (or is that a few too many beers).

From whence does purpose arise?  People always want to know why: What is the purpose? Why did hurricane Sandy hit New York? Was it punishment for past sins? The idea of purpose is so central to people’s thinking that we want a purpose for every happening. This was engrained in philosophy as Aristotle’s final cause. Aristotle regarded the final cause as the most important of his four causes and it became central to medieval philosophy. Understanding the final cause has, indeed, been important to our survival. It was important to know the reason for the lioness taking a stroll. Was she just doing it for exercise or was she looking for a meal? If the latter, it was very important to give her a wide berth. Similarly in social interactions, it is important to know the purpose behind a person’s behaviour. Are they just being nice or do they have ulterior motives? And if so, what?

Purpose or Aristotle’s final cause[1] is entirely from the physical sciences and downplayed in science generally. This leads to an argument against evolution.  Evolution by natural selection has no purpose but is a stochastic process with the direction of each step being independent of the previous step and depending only on the local conditions at that moment. Apes did not evolve to form the stock from which humans later arose but rather humans arose as a result of local environmental pressures on the ape. The precise argument against evolution by natural selection is that since natural processes have no purpose, purpose could not have arisen unless there was an outside agency to give purpose. Since purpose is seen, for example in animal and human behaviour, such an outside agency must exist. If evolution produced this purpose, it must have been guided by an external purpose and not be due entirely to natural selection.

This argument is a prime example of proof by lack of imagination. It relies on not having enough imagination to find a method for purpose to arise from natural selection.  Hence, the precise argument against evolution can be stated as: I can imagine no way that purpose can arise except by an external agency, therefore evolution must be caused by an external agency. The counter to proof by lack of imagination is the just so story. That is a story made up to explain a given occurrence without any evidence of wide spread validity. Generally, I regard just so stories as uninteresting and certainly not science[2]. To make the just so story science, one would have to use it to make testable predictions. But as a counter to proof by lack of imagination, that is not necessary. All that is necessary is that to provide one plausible counter example.  I will now give a just so story to counter the argument in the last paragraph.

So, let’s see how the illusion of purpose, if not purpose itself, could arise. Consider some bacteria in a solution with a gradient for food.  The bacterium that moves towards more food will on average produce more offspring and therefore the population will eventually be dominated by those that move up the gradient. The resulting behaviour appears to have a purpose: namely to get more food.  However, it is just the response to the local conditions, conditioned by evolution’s feedback loop.

One can apply the same type of reasoning to more complex situations and in every case evolution favours those individuals whose behavior appears to have purpose. Consider the case of a bird building a nest. Birds that build nests that do a better job of protecting their young will have more offspring (balanced somewhat by the cost of building the nest).  Similarly with the behaviour of young men courting young women (and vice versa). Those that are successful produce offspring while those that aren’t, don’t reproduce.  Thus, the behaviour seems to have a purpose but in fact, it is only that those who behave in a certain way leave offspring and hence, the behaviour is all that survives. Incidentally, this also explains why there are so few geeks.

Thus, we see that purpose, or to be more precise, the illusion of purpose, can arise from the feedback loop in evolution. Evolution favours those behaviours that work towards the end of producing more offspring, which is a purely mechanical process. But saying purpose is an illusion is perhaps going too far. In building models of animal and even plant behaviour, purpose is a useful concept that makes the job easier. Models that include purpose are simpler and make better predictions than those without and even if they didn’t, we are human after all, and do enjoy a just so story. Purpose, like the nucleon, is an emergent property[3] that arises from the underlying dynamics. So the next time you are pursuing a member of opposite sex with a definite purpose in mind, remember that purpose is, if not an illusion, just an emergent property.