Spookiness is in the brain of the beholder

Whether or not you believe in the paranormal may depend entirely on your brain chemistry. People with high levels of dopamine are more likely to find significance in coincidences, and pick out meaning and patterns where there are none.

Peter Brugger, a neurologist from the University Hospital in Zurich, Switzerland, has suggested before that people who believe in the paranormal often seem to be more willing to see patterns or relationships between events where sceptics perceive nothing.

Brugger persuaded 20 self-confessed believers and 20 sceptics to take part in an experiment in which they were asked to distinguish real faces from scrambled faces as the images were flashed up briefly on a screen. The volunteers were then asked to idenify real words from made-up ones. Believers were much more likely than sceptics to see a word or face when there wasn’t one, Brugger revealed. However, sceptics were more likely to miss real faces and words when they appeared on the screen. The researchers then gave the volunteers a drug called L-dopa, which is usually used to relieve the symptoms of Parkinson’s disease by increasing levels of dopamine in the brain. Both groups made more mistakes under the influence of the drug, but the sceptics became more likely to interpret scrambled words or faces as the real thing. That suggests that paranormal thoughts are associated with high levels of dopamine in the brain, and the L-dopa makes sceptics less sceptical. “Dopamine seems to help people see patterns,” says Brugger.

However, the single dose of the drug didn’t seem to increase the tendency of believers to see coincidences or relationships between the words and images. That could mean that there is a plateau effect for them, with more dopamine having relatively little effect above a certain threshold, says Peter Krummenacher, one of Brugger’s colleagues.

Dopamine is an important chemical involved in the brain’s reward and motivation system, and in addiction. Its role in the reward system may be to help us decide whether information is relevant or irrelevant.

New Scientist July 27 2002

That Eureka Moment: How Science Works

This article is drawn from interviews with Allan Coukell on the NZ National Radio science programme “Eureka!” in 2001.

We live in an era where science is universally needed but rarely appreciated, little understood and much misunderstood. This is not just a problem of the wider non-scientific community; science is increasingly specialised and even prestigious scientists may have little awareness of areas of science outside their specialised research niche. Science is typically learned by studying and working in a particular discipline, but often such narrow perspectives don’t allow us to reflect on wider issues about science and appreciate its strengths and weaknesses. Furthermore, the specialized, abstract, nature of much science education all too often alienates many of its victims, while leaving the survivors blind to the limits and problems of their craft. There is irony in the way that science, the ultimate questioning activity, frequently fosters such unquestioning supporters and critics.

What is science?

Obviously science comes in many shapes and sizes and any attempt to provide a “one size fits all” description is bound to fail. Some scientists are engaged in an open-ended exploration of natural phenomena; some spend their lives developing and testing theories or models. Yet more scientists try to find out whether some theoretical entities like quarks are “real”, whilst others are trying to measure properties of the world with greater and greater precision. What, if any, are the unifying features of such a diverse discipline?

Given that science is such a multifarious thing, is it even sensible to ask a question such as “what is science?” Richard Feynman was a brilliant scientist who thought it was. Feynman, winner of the Nobel Prize for Physics in 1965, was not only one of the most brilliant scientists and science teachers of the 20th Century, he also reflected on the nature of science and communicated his perspectives vividly to a wide audience. Here’s how he addresses the question “What is science?”1:

The word is usually used to mean one of three things, or a mixture of them. … Science means, sometimes, a special method of finding things out. Sometimes it means the body of knowledge arising from the things found out. It may also mean the new things you can do when you have found something out, or the actual doing of new things … so the popular definition of science is partly technology too.”

Science and technology are inextricably linked in the public’s eye; it is technology that provides the gadgets to which society becomes addicted. The reliable and informative nature of scientific knowledge underpins modern technology, but science is not simply a means to technology. As Feynman points out, it is crucial to realise that science is an intellectual adventure, a cultural activity that should be undertaken for its own sake:

“The things that have been found out [are] the gold. This is the … pay you get for all the disciplined thinking and the hard work. The work is not done for the sake of an application. It is done for the excitement of what is found out. You cannot understand science and its relation to anything else unless you understand and appreciate the great adventure of our time.”

Science is an adventure. It involves asking questions about the universe, coming up with theories about the way nature works, and testing those theories to see how valid they are. As any scientist knows, it is a challenging activity:

“Trying to understand the way nature works involves a most terrible test of human reasoning ability. It involves subtle trickery, beautiful tightropes of logic on which one has to walk in order not to make a mistake in predicting what will happen.”

Given the complexities of undertaking a scientific investigation, what is it about science that makes it such a powerful way of finding things out about the world? This is Feynman’s view:

“[S]cience as a method of finding out … is based on the principle that observation is the judge of whether something is so or not. All other aspects and char-acteristics of science can be understood directly when we understand that observation is the ultimate and final judge of an idea. But ‘prove’ used in this way really means ‘test’ … the idea should really be translated as ‘The exception tests the rule.’ Or, put another way, ‘The exception proves that the rule is wrong.’ That is the principle of science. If there is an exception to any rule, and if it can be proved by observation, that rule is wrong.”

Fireworks at NASA

Given the variety and complexity of science, scrutinising illustrative episodes of science in action is a good way to understand more about science. Again Feynman provides a lead: he not only discussed science, he exemplified the whole philosophy of questioning the world and testing scientific ideas. Early in 1986, when he was fighting terminal cancer, Feynman was once again thrust into the public eye when he performed one of the most public demonstrations of science during the inquiry into the tragic accident of the space shuttle “Challenger”. Feynman’s role in this investigation provides an illuminating vignette into science.

On January 28th 1986 the space shuttle Challenger was launched, and almost immediately exploded in a horrific fireball. It is salutary to sometimes reflect on the fallibility of science and the icons of technological sophistication. Yet science rose, phoenix-like, from the ashes, due almost exclusively to Feynman’s scientific acumen.2 Within a week of the accident, on February 4th, Feynman was appointed to a committee of inquiry. He immediately began quizzing the engineers at the Jet Propulsion Laboratory where much of the space shuttle technology was developed. On the first day he learned of well-known problems with the shuttle, including cracks in the turbine blades. Feynman also learned of problems with the O-rings – glorified rubber bands thinner than a pencil and more than 10 m long – that sealed the joins between sections of the solid-fuel rockets. A pair of O-rings had to expand to prevent the leak of hot gases during the burning of the solid fuel rockets. However, on some launches one of the O-rings was being scorched. Feynman jotted down some notes: “Once a small hole burn thru generates a large hole very fast! Few seconds catastrophic failure.”

Feynman flew to Washington and quizzed NASA officials, especially about the effects of the unusually cold weather at the launch of the Challenger shuttle. Because the elasticity of the O-rings would decrease at low temperatures, the problems with the O-rings would be exacerbated. Over the weekend Feynman was hot on the O-ring trail and, when the committee reconvened on Monday 12th February, he was frustrated by the inconclusive and evasive testimony of Lawrence Mulloy, the project manager for the solid fuel rockets. That night at dinner, his eyes fell on a glass of iced water and he saw a way to test whether 0oC (the temperature of the Challenger launch) would affect the resilience of the O-rings.

The next day he bought a small C-clamp and pliers. At the hearing Feynman asked for iced water and then broke off a bit of O-ring material as a sample was passed round. He clamped the O-ring material in the C-clamp, then after a short break in the proceedings, Feynman asked to speak to Mulloy. The rest has become a historic exchange captured by the TV cameras:

“I took this stuff that I got out of your seal and I put it in ice-water, and I discovered that when you put some pressure on it for a while and then undo it, it doesn’t stretch back … In other words, for a few seconds at least … there is no resilience in this particular material when it is at a temperature of 32 degrees [Fahrenheit]. I believe that has some significance for our problem.”

Here, in a nutshell, was the heart of the scientific problem. As another great theoretical physicist, Freeman Dyson, commented:

“The public saw with their own eyes how science is done, how a great scientist thinks with his hands, how nature gives a clear answer when a scientist asks her a clear question.”

Stages of the scientific process illuminated by Feynman’s experiment:

  1. Science starts with a problem: in this case the question of what caused the Challenger to explode.
  2. There is background detective work: finding out what is already known (in most scientific investigations this involves extensive literature work; here it involved garnering various streams of evidence such as the previous O-ring problems, the observed puff of smoke from the solid booster after 0.5s of flight, the lower resilience of rubbers at lower temperatures etc).
  3. Hypothesis formulation: that a momentary loss of resilience of the O-ring allowed hot gases to burn through the seal and caused the rocket to leak.
  4. Hypothesis testing via experiment, or observation: testing that the elasticity of the O-ring material was indeed compromised under the conditions of the launch.
  5. Bringing the results into the public arena for critical scrutiny: committee hearings are an unusual forum for discussion; for most research investigations the academic literature is where scientific claims are subject to critical scrutiny.

What does the Challenger inquiry tell us about science?

Without Feynman’s input, the committee of inquiry was likely to have been a whitewash. Most of the establishment would have liked to rubber stamp the worthiness of the shuttle programme. Scientists have to be careful about not falling into the trap of defending the work of a programme they believe in, rather than subjecting it to full critical scrutiny. Feynman, as the consummate scientist, shows that science is not about confirming your prejudices or defending your patch, it is about uncovering truths about the world.

Feynman’s beautiful experiment did not absolutely prove that problems with the O-rings caused the Challenger disaster. However, together with the history of problems with the shuttle and the particular climatic conditions for the launch, the case was proved “beyond reasonable doubt.” Scientific knowledge bears more than a passing resemblance to court proceedings: the more direct the experimental evidence, and the greater the accumulated weight of diverse lines of evidence, the more clear-cut scientific knowledge becomes.

Science is not a method of generating infallible truths about the world; only tyrants claim to do that. Neither is it simply a way of producing just another opinion about the world – no better or worse than any other (as many postmodern social scientists would have us believe). While science does not dispense absolute truths, it does produce the best knowledge we have in areas where we can subject our theories to rigorous tests. Although the theories that survive such tests can never be proved to be true, they are likely to be close to the truth if they survive detailed scientific scrutiny without being proved wrong.

Furthermore, in areas where theories have been well tested and flaws of the theory are exposed, it is often the case that the theory is not thrown out wholesale – instead the previous theory is often found to be a limiting situation for the theory that succeeds it. We are more confident in the predictions of Newtonian mechanics in the wake of Einsteinian mechanics than we were before, since we now clearly understand where it does and does not apply. Similarly we have not dispensed with atomic theory now we know that atoms are comprised of smaller entities.

So the heart of science is criticism, the use of observations and experiments to test our theories and always being able to accept that we might be wrong. The ability to modify our views, in the face of evidence, is a keystone of science.

Perhaps the last word should go to Feynman3:

Science is a way to teach how something gets to be known, what is not known, to what extent things are known (for nothing is known absolutely), how to handle doubt and uncertainty, what the rules of evidence are, how to think about things so that judgments can be made, how to distinguish truth from fraud and from show.”


1 The quotations in this section are from Chapter 1 of The Meaning of it All, R. P. Feynman which is drawn from a public lecture that Feynman gave in April 1963.
[Back to text]

2 For a slightly more detailed chronology of Feynman’s participation in the Challenger investigation see Genius, by J. Gleick, pp414-428.
[Back to text]

3 Quoted in Genius, by J. Gleick, p285.
[Back to text]

This article originally appeared in Chem NZ No. 86.

Existence of ESP confirmed

It’s often claimed either that science doesn’t have the tools to identify ESP, or that scientists have a prejudice against the whole idea. But American researchers have recently confirmed that certain individuals are indeed able to detect an energy field given off by living creatures in the absence of any other sensory cues. The only thing is, those individuals are young paddlefish.

This large, shark-like species lives in the muddy waters of the Mississippi, filtering plankton from the water with its gills. Young paddlefish use sensory organs on the sword-like “paddle” which extends in front of the mouth to detect prey animals (mostly small crustaceans) individually by the electric fields they produce. Some marine sharks, and the duck-billed platypus, have similar abilities. Still no sign that Homo sapiens can work this particular trick, however.

New Scientist, 7 April

The Spectre of Kahurangi

Goethe’s Faust is a tale of the supernatural. According to a famous passage, on Walpurgisnacht a witch’s sabbat was celebrated on top of the Brocken, a mountain in the Black Forest. Old maps show this point circled by witches on broomsticks. Although probably not a very ancient tradition, it grabbed the imagination of 19th century romantics. They claimed at certain times magical visions could be seen from the peak. Even though no witches were visible on the mountain, gigantic shadowy figures were projected onto the clouds; the Spectre of the Brocken.

According to the Encyclopaedia Britannica “this phenomenon is often observed on mountain peaks” but even the non-supernatural explanations seem unbelievable. According to the Britannica “When the sun is low, shadows cast by the sun become magnified and seemingly gigantic silhouettes are cast on the upper surfaces of low-lying clouds or fog below the mountain.”

A later entry is contradictory: “The apparent magnification of size is an optical illusion that occurs when the observer judges his shadow on nearby clouds to be the same distance as faraway objects seen through gaps in the clouds.”

So is the magnification real or an illusion? As the sun’s rays are practically parallel, any shadow cast by the sun remains the same size as the object. Thus a shadow at even a modest distance from the observer can only seem small. In justification Britannica mentions the common sight of an aeroplane’s shadow cast on clouds beneath, but a jumbo jet casts a decent sized shadow, a human sized shadow would be insignificant.

In spite of many literary references (De Quincey for example) first-hand accounts of “the Spectre” by first-rate observers seem non-existent. (Does any reader know of any?). But some accounts state that the figures seem frightened of the observer and rush away as soon as they are seen.

The whole thing seems ridiculous, or so I thought until I saw the phenomenon myself in New Zealand. In fact I have observed this effect twice-which considering the time I have spent in the mountains, implies it is a relatively rare event.

The first occasion was when climbing a ridge above the Wangapeka River in what is now Kahurangi National Park. The sun rose over another ridge behind us and gigantic shadow figures appeared on the hillside across the valley. Before I had fully grasped what was happening they had shrunk down to normal size, where they were just visible. At least that explained the accounts of figures “rushing away”, they simply got smaller, and very rapidly too.

The explanation was quite obvious to anybody with some knowledge of optics; light is refracted when passing over an edge. The first gleam of sunlight over the ridge was bent into a widening beam that produced a huge shadow as effectively as a point of light projects an enlarged shadow onto a screen. The bush-clad hillside opposite us acted as a screen on which we could see the projection. But as the sun rose, the refraction diminished until enough of the sun was visible to produce the normal parallel rays with which we are familiar. So the initial large shadow quickly shrank to normal size.

Was this illusion awe-inspiring? Was it even an illusion? Were we frightened? Was it immediately obvious that we were observing our own shadows not supernatural entities? Well no, no, no, and yes. My wife, the complete skeptic, summed up, “Why make a fuss about shrinking shadows?”

I am confident that I can explain the reports of run-away shadows in mountain regions. The conditions necessary for observing this phenomenon seem to be that the sun must rise over a not too distant sharp edge, the air should be still and very clear. The observers be on a minor peak or ridge, and the projection be onto a fairly plain surface.

Does this explain the “Spectre of the Brocken” better than the Encyclopaedia? Well to be honest, no. The Brocken is the highest mountain around. So how could the sun rise over a sharp edge unless other peaks are very close? I doubt that clouds can ever have sufficiently sharp edges to produce the effect.

Perhaps the Spectre of the Brocken is as real as the reports there of witches, while its magical reputation has seen it acquire stories of phenomenon that are real in other mountainous areas.

Evolution: The Fossils Say YES!

The old creationist claim that there are no transitional forms in the fossil record is starting to look a bit tired

A perennial contention of creationists opposed to evolution is that transitions or intermediates between the major groups (classes) of vertebrates (animals with backbones) do not exist. The most persistent critic of the part played by the fossil record in providing evidence for evolution is Dr Duane Gish of the Institute for Creation Research in the United States. His arguments are expressed in two books, Evolution: The Fossils Say No! and the updated version, Evolution: The Challenge of the Fossil Record. The aim of this paper is to show that the above contention is without foundation. A classic example of a transitional form (the ancient bird, Archaeopteryx lithographica) will be examined, as well as an example of evolutionary transformation, the evolution of ear bones in vertebrates.

Discovered in 1860, one year after publication of the Origin, Archaeopteryx is of late Jurassic age. About the size of a magpie, it lived some 150 million years ago. The species is represented by seven skeletons and one isolated feather. Close examination reveals a mixture of reptilian and bird features with many more of the former than the latter. (The table below lists some of the key features). In fact, two specimens in which the feathers were not immediately recognized were initially misidentified as Compsognathus, a small bipedal dinosaur. It is often stated that if it were not for its feathers, Archaeopteryx would be classified as a small dinosaur. A transitional form between major groups is defined as a fossil which possesses a mixture (or a mosaic) of features usually associated with each of the two groups, one set ancestral (“old”), the other derived (“new”). Archaeopteryx fits the bill perfectly. Its reptilian ancestry is patently obvious.

Bird features Reptilian features
Feathers (the defining bird feature) Long bony tail
Toothed jaws
Three functional fingers with grasping claws
Feathered wings Clavicle (wishbone) boomerang-shaped as in some dinosaurs
Pelvis more reptilian in shape than in later birds
Table 1. Characteristics of Archaeopteryx

But not according to the creationists. In spite of the evidence outlined above and more fully discussed in advanced textbooks, they continue to proclaim that “a bird, is a bird, is a bird”. Thus Dr Morris: “The Archaeopteryx is a bird – not a reptile-bird transition.” And Dr Gish: “It was not a half-way bird, it was a bird”. In this regard it should be emphasized that a fossil does not have to be exactly intermediate in its features in order to be considered transitional. A mixture of definitive features, old and new, is sufficient. The period of transition between bony fish and the first amphibians, for example, is characterized by forms in which the mosaic patterns show varying rates of change of specific features in different genera.

Archaeopteryx hit the headlines a few years ago with the allegation that it was a fraud.

This assertion was made by the astronomer, Sir Fred Hoyle. He claimed that a forger had tampered with the fossilized skeleton of Compsognathus, adding impressions of feathers. This prompted scientific testing at the Museum of Natural History in London. Hoyle’s view, which must have been welcomed as grist to the anti-evolutionary mill, was proved groundless. The feather impressions were naturally formed. This early bird is still the de luxe example of a transitional form.

Now to a classic example of evolutionary transformation, a process whereby a structure becomes modified over time and changes in its primary function. Mammals almost certainly arose from a group of reptiles, aptly named the mammal-like reptiles, some 200 million years ago. The more advanced of these reptiles show trends towards the mammals in a number of features, such as improved locomotion by adopting an upright posture and differentiation of the teeth for the efficient exploitation of food sources. Palaeontologists normally are restricted to skeletal features for classifying a fossil. Soft tissues are seldom fossilized. The lower jaw or mandible in mammals is a single bone (the dentary which carries the teeth), in contrast to that of reptiles which comprises several bones. In addition, the middle ear of mammals contains three ear bones; reptiles have but one, the stapes.

The stapes can be traced to the fish stage of vertebrate evolution. (See fig. 1). The first fishes lacked true jaws. Hence many were filter feeders, extracting food from the stream of water entering the mouth and filling the pharynx. The filtered water then passed out through holes (gill slits) in the wall of the pharynx. The regions between the slits were supported by a basket of linked bones forming the branchial or gill arches. Jaws probably arose from a pair of these arches (another example of transformation). The upper element of the arch immediately behind the jaws eventually became transformed from an unspecialized part of a gill arch into a prop (the hyomandibular) to support the jaws at their region of articulation. It was thus ideally positioned, given its upper attachment to that region of the braincase which housed the organs of balance and hearing, to become a specialized sound transmitter, a potential realized later in the amphibians. The stapes (the transformed hyomandibular) greatly improved hearing on land.

The origin of the other two ear bones in mammals is even more intriguing. During the evolution of the mammal-like reptiles, the dentary bone in the lower jaw expanded greatly in order to provide greater surface area for the attachment of more powerful jaw muscles. At the same time the canines enlarged as efficient instruments for capturing and dismembering prey. Fig.2 shows the lower jaw of an advanced mammal-like reptile, Cynognathus For the sake of clarity the articular bone of the lower jaw is shown detached from the quadrate bone of the skull. In life these two bones form the jaw joint of reptiles. The expansion of the dentary involved two regions, the ascending coronoid process and the triangular articular process at the back (not to be confused with the articular bone).

In some mammal-like reptiles the articular process had grown back to the point where it touched the skull itself. This development created the potential for a new jaw joint formed by the dentary of the lower jaw and the squamosal bone of the skull. In fact, there are several examples of varying degrees of development of the “new” jaw joint, from rudimentary to fully functional, perfect examples of transitional stages, making the classification of such forms (reptile or mammal?) difficult. Should we be concerned? Not at all. Such “tricky” forms are to be expected in evolution. There is a continuity here which negates the creationist thesis of there being no transitional forms in the fossil record.

But the story is not yet over. The “new” mammalian jaw joint, once it became fully functional, rendered the “old” reptilian one superfluous. The bones of the “old” joint now relieved from a jaw articulation function were free to assume a new primary role. In this case it was not strictly a change of function but an enhancement of an existing minor function – sound transmission. The articular and quadrate bones were already somewhat inefficient conductors of sound to the inner ear in the early land vertebrates. The two bones underwent transformation to become ear bones and joined the stapes or stirrup in the middle ear to form a trio of efficient sound transmitters, greatly improving the conduction and amplification of sound waves from the outer to the inner ear. The quadrate became the incus (anvil) and the articular became the malleus (hammer). The improvement in hearing is linked to the importance of this faculty (along with smell) in promoting the survival of the first mammals as small nocturnal animals in a world dominated by large and aggressive dinosaurs.

What has Gish to say on the subject? He refers to the “unbridged gap between reptile and mammal” and questions how the “intermediates” managed to hear while the changes described above were going on. He seems to have overlooked the fact that the stapes was still present. In addition, as was pointed out above, the “old” jaw joint bones were already sound conductors. He also expresses concern as to how the animals continued to chew while the changes were in progress. But there was never a time when an “intermediate” was without functional jaws. The sequence of change with respect to jaw joints was: Old > Old + New > New.

Diarthrognathus epitomises the transition from reptile to mammal. In this animal, not only was the “old” reptilian joint between a reduced quadrate and articular present, but also a “new” and fully functional mammalian one. To cite a further example, Probainognathus also possessed a double articulation between skull and jaw. Furthermore, the quadrate bone, now only loosely joined to the rest of the skull, was intimately articulated with the stapes bone of the middle ear.

On the above evidence I rest my case. Transitional fossils between major groups of vertebrates do exist and lend powerful support to the reality of evolution.

Can Sharks Save the Human Race?

A RELATIVELY recent development in Western society has been the increased popularity of health foods and dietary supplements. While initially these health foods could only be purchased through a sparse number of “alternative retail outlets” manned by the converted, as sales have grown and the realisation of the potential profit has become obvious to more people, availability has become easier. There has been a mushrooming of “Health Food Shops”, an increasing number of supermarkets have established “Health Food Bars” and many conventional pharmacies have made the sale of these products a feature of their business.

Continue reading