Archive for February, 2012

Feb 28 2012

Religious Freedom vs Consumer Protection

A Christian church in New Zealand has put up a billboard on their property that proclaims: “Jesus Heals Cancer.” This has caused a bit of a stir and prompted a discussion about the limits of religious freedom vs protecting the public from false or misleading claims.

The Pastor, Lyle Penisula, holds that the claim is true. This is actually the easiest aspect of the this issue to deal with – is there evidence that “Jesus heals cancer?” No. The Pastor himself offers, of course, anecdotes – cases of people in his church who survived cancer. He admits that they completed whatever treatment regimen they were being given by their doctors, but seemed to entirely miss the point that therefore we cannot conclude that it was Jesus who healed them. They may have simply responded to standard medical treatment.

There has been a fair bit of research into intercessory prayer. The results are essentially negative. More studies are negative than positive, and the positive ones have critical flaws (although they seem to get more media attention). If there were a clinically significant effect from intercessory prayer the existing studies would have shown a more consistent and clearly positive signal. What we have is most consistent with no effect. The evidence is incompatible with the claim that “Jesus heals cancer.”

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Feb 27 2012

FTL Neutrinos? Einstein Can Rest Easy

Published by under General Science

Last September the OPERA collaboration in Italy announced that they had detected neutrinos apparently traveling faster than the speed of light. In their experimental setup the neutrinos arrived about 60 nanoseconds ahead of what the speed of light would have produced. The first persons to be skeptical of this result were the researchers themselves. They understood that this result is at odds with perhaps the most confirmed theories in all of science – Einstein’s theories of special and general relativity. According to relativity theory nothing can travel faster than the speed of light in a vacuum. This is not a practical limitation, it is inherent to the fabric of the universe.

Every now and then a lab somewhere claims to have broken this law of relativity, but in every case (so far) it seems that they simply made an experimental error or interpreted their results incorrectly. This ultimate speed limit seems to be as solid a law of physics as the conservation of energy, and experiments that seem to break this law suffer the same fate as those who believe they have invented a perpetual motion or free energy machine.

This claim, however, was different because the scientists exhaustively searched for any possible source of error they could think of and eliminated it, and the 60 nanosecond discrepancy persisted. Only when they did everything they could to disprove their results did they announce them to the world – still with the proper caution that was due. They essentially asked the rest of the scientific community to help them find the source of the error, while tentatively saying that if their results are true, wouldn’t that be interesting.

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Feb 24 2012

Richard Dawkins – Agnostic

This is actually old news – Richard Dawkins, perhaps the world’s most famous atheist, discusses atheism vs agnosticism at length in his book, The God Delusion (you can listen to the relevant section here.) In a recent debate with the Archbishop of Canterbury, Dr Rowan Williams, Dawkins acknowledged that he is not 100% certain of God’s non-existence, and when asked if he is therefore an agnostic, he said that he was.

These statements have to be put into context, however – which Dawkins did in his book and elsewhere. In The God Delusion he outlines 7 stances toward the probability that God exists. He put himself into category 6, a strong atheist but less than 100% certain that God does not exist. He states he is less than 100% certain as a matter of principle – because a mere human cannot be 100% certain of anything. Only fanatical belief results in 100% metaphysical certitude. So he is as strong an atheist as a rational and intellectually honest person can be.

How, then, can we make sense of Dawkins acknowledging that he is also an agnostic. A report of the debate states:

The philosopher Sir Anthony Kenny, who chaired the discussion, interjected: “Why don’t you call yourself an agnostic?” Prof Dawkins answered that he did.

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Feb 23 2012

The British Chiropractic Association Reflects on the Simon Singh Affair

Richard Brown, president of the British Chiropractic Association (BCA), has a tough task before him.  He presided over the BCA’s libel suit against Simon Singh for an article he wrote in the Guardian in which he specifically criticized the BCA, writing that it, “happily promotes bogus treatments.” The libel suit resulted in a magnification of criticism against the BCA by orders of magnitude, and the questioning of onerous libel laws in Britain that stifle free speech. The BCA ultimately had to withdraw the suit and pay for Singh’s outrageous legal expenses.

In a recent speech Brown reflected on the Singh lawsuit, now published in the Chiropractic Report with the title, “After the Storm – What Have We Learnt?” As Edzard Ernst noted in an article about Brown’s speech, “it makes fascinating reading.” To me it reads like desperate damage control, but in it there are some interesting admissions.

Regarding the Singh affair Brown writes:

Singh claimed that the BCA ‘happily promotes bogus treatments’ even though there was ‘not a jot of evidence’. The BCA was faced with a dilemma. Did it sit by and permit an assault on its reputation and good name, or did it stand up for its members and challenge the criticism? For years, chiropractic had been castigated in a succession of critical articles, but here was a published article which had explicitly named a chiropractic association and had made defamatory comments about it.

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Feb 20 2012

Can You Figure Out This Ghost Photo?

Published by under Paranormal

I am on vacation this week. So for my blog this morning I am going to do a quickie – here is a photo I was just sent by an SGU listener. They wanted our help in explaining the rather creepy image on the photo. Before I even read the e-mail, however, the sender sent another e-mail saying that they figured out the answer. Take a look and see what you think. I will post the answer in a couple days as an addendum below the fold.

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Feb 20 2012

Evolution – It Could Have Turned Out Differently

Published by under Evolution

A century and a half ago scientists knew very little about how life works, at least compared to what we know today. They knew little about the organelles that make up each living cells, the biochemical pathways involved in living processes, and knew absolutely nothing about genetics (which didn’t even exist yet as a discipline). It was in this context of relative ignorance that Charles Darwin proposed his particular theory of evolution and presented his argument for common descent and natural selection. The notion of evolution and common descent predates Darwin – scientists before him noticed a pattern in the sequence of fossils appearing in successive geological layers. Life seemed to be changing over geological time, with species in younger layers seeming to be derived from species in older layers.

Darwin added to that that basic observation his extensive personal observations of nature – that there is actually a great deal of variation within species, and that many species on the Galapagos seem to be derived from related species on the mainland, but changed to adapt to various niches on the islands. Still, evolution through natural selection was a remarkable hypothesis, but little more than a hypothesis. It is perhaps a good thing that there was so much left to discover about basic biology when evolution was proposed, for that created the opportunity to test this crazy theory.

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Feb 17 2012

The Autistic Brain at 6 Months

Published by under autism,Neuroscience

Yet another study showing that clear signs of autism are present as early as six months of age has been published. In this study researchers looked a high-risk children (siblings of children with autism) at 6 months with MRI scanning (specifically diffusion tensor imaging) and then evaluated them clinically at 24 months to see which children met criteria for autism spectrum disorder (ASD). Some of the children also had imaging at 12 months. The imaging was used to look at the development of white matter – the tracks in the brain that contain the axons or pathways of communication.

When compared as groups the 28 infants who went on to develop ASD had significantly decreased white matter development in 12 of 15 brain pathways examined in comparison to the 64 infants who did not develop clinical ASD.  These results are very robust, although I should point out that the children were compared as groups, not individuals. The purpose of this study was to see if there were detectable changes in the brains of children with ASD at 6 months, not necessarily to explore its utility as a diagnostic tool that can be applied to an individual.

Still, this study supports other research providing increasing evidence that ASD begins at least as early as 6 months. It is probable that ASD begins earlier than 6 months, actually, because in order for detectable differences to be present in the brain, development must have been heading down a different trajectory prior to that. These kinds of studies have not looked at children younger than 6 months, and it would be interesting to see how early such changes can be detected. But even without that data, we can conclude the whatever process results in ASD it is active prior to 6 months so that the effects are detectable at 6 months.

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Feb 16 2012

Mercury Still Not Correlated with Autism

Published by under autism,Neuroscience

Another study, published recently in PLoS One, fails to show a correlation between mercury and autism. This was a study of mercury excretion in the urine, comparing subjects with autism to their siblings as well as controls without autism spectrum disorder (ASD), both in mainstream and special schools. They found no significant difference among the groups, even controlling for kidney function (creatinine clearance), age, gender, and amalgam fillings.

To put this study into context – there are those who claim that mercury toxicity is what causes ASD, and in fact ASD is simply misdiagnosed mercury toxicity. There is no question that mercury is indeed a neurotoxin, but toxicity is all about dose, so the question is are children being exposed to mercury in high enough dose to cause toxicity. Further, it is difficult to extrapolate from preclinical studies (in test tubes and petri dishes) to living organisms. We need to further know what happens to the toxin in the body, and how the body handles it.

With regard to the forms of mercury found in some vaccines (although much less than in previous years) and tuna fish, the body seems to rid itself of the mercury sufficiently quickly to prevent build up to toxic levels. Of course, this remains a hot topic because of the persistent claims by the anti-vaccine movement that vaccine cause ASD, and some who cling to the discredited notion that it is mercury in vaccines that is the culprit. There are also the so-called “mercury militia” who blame environmental mercury (from vaccine and elsewhere) on all human illness, not just autism.

As further background, it’s helpful to note the chain of argument that has occurred with respect to the role of mercury in autism. Studies have consistently found no correlation between mercury exposure and the risk of ASD. Proponents of the mercury hypothesis have therefore argued that there is a subpopulation of vulnerable children who metabolize and excrete mercury differently than the general population, and it is within this subpopulation that mercury causes ASD.

Logically this may be true, but the argument is little more than special pleading, although a common one. Scientists are familiar with the usual list of special pleading arguments made to dismiss negative evidence. These include: that the dose studied was too low, the treatment duration was too short, the placebo or comparison treatment was also effective, or the looked-for effect only exists in a subpopulation. Each one of these arguments is logically consistent – if true they would explain the negative results without meaning that the phenomenon is not true. They may even be true in specific cases. What makes them special pleading is when they are invoked ad hoc to explain negative evidence without good justification.

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Feb 14 2012

Love is in the Brain

Published by under Neuroscience

As you cuddle with your mate your brain receives a comforting surge of oxytocin, reinforcing your feelings of attachment. More intimacy gives your pleasure centers a shot of dopamine, strongly reinforcing the behavior. Your brain becomes increasingly bathed in dopamine, serotonin, and other hormones and  neurotransmitters, resulting in a suite of physiological and behavioral responses evolved to maximize the probability of inserting your genes into the next generation.

In the afterglow of your subconsciously Darwinian act, you contemplate what attracted you to your mate in the first place. If you are male then you probably responded positively to a certain waist to hip ratio indicating good birthing potential. Full lips and facial features with a rosy tone to the skin also indicates youth and health – other good predictors of of breeding success.  Females are also attracted to signs of health and vigor, but also dominance and power (however this specifically manifests in your culture).

Evolutionary changes to your brain’s hardwiring and chemistry have spared you the tedious task of performing a biological assessment of potential mates. Rather, you just have an automatic feeling – an attraction – that is largely based upon a cold subconscious calculus of breeding and life success. You find yourself thinking obsessively about a good mating prospect. You may feel giddy just by being in their presence. The mere sight of them gives you a pleasurable spike of dopamine.

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Feb 13 2012

An Online CAM Poll

Online surveys are worthless. That is, they are worthless as a source of information about popular belief and opinions. Yet many people still find them compelling, and so they can be useful as a way of driving traffic to your website. I guess that’s why they persist.

A recent poll about teaching complementary and alternative medicine (CAM) in Australian universities has become a matter of unnecessary controversy. Asher Moses wrote an article complaining about the fact that the survey seems to have been “gamed”, in an article: Vote on alternative medicine falls victim to dark arts of the internet. In the article he seems to miss the two real points about the poll – surveys are not reliable, and it’s fallacious to use them as an argument from popularity anyway.  He writes:

Voting progressed steadily at first but on Tuesday votes began rising from about 125,000 to more than 877,000 by the time voting closed on Thursday. The end result was 70 per cent no, 30 per cent yes.  The number of votes in the poll was about eight times more than the number of online readers of the story, a clear indicator that the poll had been gamed.

Moses talks in the article about how easy it is to “game” an online survey, but that is not the real issue. Most surveys are probably not hacked, as indicated above it is easy to detect such manipulation. Rather, there is a problem inherent with polls and surveys.  The only reference to this issue in the article is acknowledgement that the survey was not “scientific” – but what does that mean, exactly?

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