Archive for April, 2012

Apr 30 2012

Another Cell Phone – Cancer Review

There is an ongoing scientific discussion about the safety of long term cell phone use. The primary question  is whether or not long term exposure to non-ionizing radiation can increase the risk of brain cancer. There are further questions about whether or not such radiation can cause any health problems or symptoms.

As with any complex area of scientific research, perhaps the best way to evaluate the question is to put together a panel of experts to review all the existing evidence and then come up with a consensus opinion about that evidence. This is no guarantee of being right – the primary issue that tends to come up with such expert panels is that they were systematically biased toward one side of the debate. But assuming no major asymmetry in the constitution of an expert panel, they are an excellent way to evaluate the current state of the evidence on a specific question. Even better, of course, is when multiple independent panels all agree.

Recently an expert panel for the UK’s Health Protection Agency (HPA) reviewed the evidence for cell phone safety concluded that there is no clear evidence for any harm. This is good news. Their findings are similar to other reviews of the evidence, although often there is a difference in emphasis. For example, last year the International Agency for Research on Cancer (IARC) reviewed the same evidence and concluded that:

 ”the evidence, while still accumulating, is strong enough to support a conclusion and the 2B classification. The conclusion means that there could be some risk, and therefore we need to keep a close watch for a link between cell phones and cancer risk.”

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Apr 27 2012

GPS for Pigeons

Published by under General Science

Pigeons have an uncanny ability to navigate accurately over long distances. This has been clearly established and exploited for centuries. Yet scientists are still uncertain about the underlying biological basis for this ability. There are four basic mechanisms that pigeons appear to use in returning to their home loft from an unfamiliar location. They use the position of the sun, the magnetic field of the earth, visual cues, and the dispersal of odors in the environment.

Pigeons, therefore, may get a general direction and orientation so that they know which direction to head in. Once they get to familiar territory they then can use visual and olfactory information to zero in on their home. There has been robust research and at times fierce debate about all of these mechanisms. The one that seems to get the most attention in the press is the orientation to the earth’s magnetic field, which is the subject of a new interesting study.

Researchers looking at the brains of pigeons have found 53 neurons that appear to fire in response to the presence, strength, and orientation of an external magnetic field. If true this would point to an important component of the pigeons “gps” system for sensing not only their directional orientation, but perhaps even their general location. The neurons also seemed to have a maximal response to the approximate field strength of the earth’s magnetic field.

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Apr 26 2012

The Faint Young Sun Paradox

Earlier this week I wrote about paradoxes in science, about how they are good things pointing the way toward new research and possibilities. Science deniers, however, exploit them to cast doubt on established science, without creating a viable scientific theory of their own. I gave as an example the solar neutrino problem – the fact that in the 1980s and 1990s neutrino detectors were detecting 1/3 to 1/2 the solar neutrinos than the standard model of particle physics predicted. Creationists used this to argue that the entire nuclear fusion model of stars was wrong.  It wasn’t long, however, before the missing neutrinos were discovered and the paradox resolved.

Recently I was asked about another sun-based paradox that creationists use to argue for a young earth – the faint young sun paradox. This was first pointed out by Carl Sagan and George Mullen.  Our models of stellar evolution indicate that the sun has been getting steadily brighter and hotter over the last four billion years. As hydrogen is fused into helium and helium therefore builds up on the core of the sun, it has to burn a little hotter in order to maintain equilibrium. The sun is burning about 30% hotter today than it was four billion years ago.

The sun is the major source of heat for the earth’s surface, and therefore a colder sun in the past would mean that the earth was colder, by about 25 °C.  By this factor alone the earth should have been mostly a ball of ice and snow up until 1-2 billion years ago. However the geological evidence points strongly to there being liquid water on the earth even when it was young.

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Apr 24 2012

The Paradox Paradox

Paradoxes exist in science for a very good reason. Science is a human-wide effort to understand how the universe works. When functioning properly it is therefore transparent and open. Further, science is describing one reality, and therefore all of the various scientific models for how bits of the universe work must all be compatible with each other. Science needs to all mesh into one big model of reality. Science also follows rules of evidence, logic, and cause and effect. You cannot invoke magic or arbitrarily suspend laws of physics as needed.

When one bit of evidence or scientific model contradicts another (they both cannot be correct at the same time) we have a scientific paradox. Since our models of reality are incomplete (and arguably always will be) scientific paradoxes pop up all the time.

How one responds to a scientific paradox reveals a great deal about how they approach science and knowledge. Those who crave certainty are made uncomfortable by paradoxes because they point to uncertainty. To a scientist, however, paradoxes are nothing less than awesome, the holy grail, the best thing since sliced bread. To a scientist an apparent paradox (really all scientific paradoxes are temporarily “apparent”) is a bright neon sign proclaiming, “This way for discovery!”

Paradoxes do not exist in reality, only in our current models of reality, and so they point the way to flaws in our current models. They therefore also point the way to further research to improve those models, fix errors, or fill in missing pieces. In short, scientists love paradoxes.

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Apr 23 2012

Report from NECSS 2012

Published by under Skepticism

I spent this past weekend at NECSS 2012 – the North East Conference on Science and Skepticism. I won’t bore you with details you can get from looking at the NECSS website. I just want to give some random observations of what I think these conferences tell us about the state of the skeptical movement.

This is the fourth year of NECSS, and overall it was a very successful conference. We pretty much sold out our 400 seat venue. At the end of the conference Jamy Ian Swiss, our MC, polled the audience, asking if it was their first NECSS and also if it was their first skeptical conference. I was a bit surprised to see that most of the audience raised their hands to both questions. This is definitely a good thing – we appear to be bringing new people into the movement, as self-identified skeptics, and they are coming to our conferences. NECSS is also very much a science conference, and we market it that way, so it’s possible many of the attendees were there primarily for the science.

In my conversations with those attending, however, the prevailing sentiment was that NECSS was more than a science conference, but a cultural event for them. For those attending such a conference for the first time they felt it was almost a transformational experience. Many people have expressed this to me over the years of producing the SGU – they feel isolated in their family, their social circle, and their community. They feel they are the only one who thinks as they do – meaning skeptically. Being surrounded by 400 people who share a similar world view, all enjoying a shared experience of listening to presenters talk about science and celebrate rationalism was a new and profound experience for them.

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Apr 19 2012

Responding to a Szaszian

Published by under Neuroscience

I have a strict “do not feed the trolls” policy on this blog. OK – so it’s more of a strong suggestion frequently flouted. It’s very difficult to enforce. Even saying, “Do not feed the trolls,” is feeding them, and there always seems to be someone who caves to their goading, and then the troll is off to the races.

Commenter Dirk Steele has given us the latest example on my blog from Tuesday. He left a completely off-topic comment with the intent of derailing discussion on the actual topic of the blog post, and someone caved (no hard feelings, I sometimes do it myself, it’s hard to resist sometimes). Dirk was apparently frustrated that I was not responding to his comments on a five year old blog post. I rarely respond to comments on posts more than a week old, let alone five years (I trust you understand why I cannot maintain active discussions on over a thousand posts).  I also did not respond because Dirk did not address any of the points I made in the post (actually a series of five posts), but was simply regurgitating Thomas Szasz mental illness denial talking points. My responses, in other words, were already in the posts and did not need repeating.

But it has been a while since I have addressed the issue of mental illness denial head on. I also receive frequent requests to discuss this topic, and ADHD (attention deficit and hyperactivity disorder) directly, so this is as good an excuse as any to revisit this topic. I predict my response will not satisfy Dirk, but at least it will keep him out of other threads for awhile. This is Dirk’s most relevant comment, in which he gives us a Gish gallop of standard mental-illness denial talking points:

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Apr 17 2012

Alternative Medicine’s Attack on Science

If you have been paying attention it is quite clear that at the core of the CAM (Complementary and Alternative Medicine) movement is a deliberate and calculated attack against science as the basis for medicine and health care. The original brand of “alternative” medicine was the most accurate – it is an alternative to science and evidence-based medicine. The later terms, “complementary” and “integrative,” are deceptions meant to distract from the fact the CAM (as much as general statements can be made about such a loose category) is anti-science, and therefore cannot be integrated into science.

Fortunately for those of us who are trying to increase public awareness about the anti-science agenda of CAM, CAM proponents frequently show their hand. They advocate for changing the rules of evidence to suit their needs. They talk about integrating their therapies with science-based medicine, but then pull a bait and switch and push pure pseudoscience as first line treatment. They dismiss and denigrate legitimate science as if it were all a big corporate conspiracy. They advocate for (and are slowing getting) laws to weaken the science-based standard of care for medicine. And of course, they distort and misrepresent real science and promote abject pseudoscience.

Perhaps none are worse in their broad-based attack on science than the homeopaths. Really, if they are going to promote homeopathy, they have no choice. Homeopathy is pure magical pseudoscience, and it doesn’t work. A thorough review by the British government recently concluded that homeopathy is “witchcraft.” Science, therefore, is the homeopath’s worst enemy (as homeopath Werner aptly demonstrates in this hilarious YouTube video). To the homeopath there is no more frightening phrase than, “Science-Based Medicine.” To survive they must either destroy science or break it to their will (which would destroy science).

Orac brought my attention to the latest attack against science by a homeopath, Heidi Stevenson. He does a fine job of deconstructing the nonsense, but I feel the need to add my own comments. Stripped down the article has two points to make: anecdotal evidence is not only legitimate, it’s the best form of evidence; and science-based doctors use mostly anecdotal evidence too. Both points are wrong.

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Apr 16 2012

Multitasking – Can You Walk and Chew Gum at the Same Time?

Published by under Neuroscience

Multitasking – the act of doing more than one thing at the same time – is largely an illusion. You can’t do it, at least not well. The research over the last couple of decades has shown in numerous ways how difficult and wasteful attempting to multitask is. Now a new study purports to show a possible benefit to multitasking. I will get to that study later – first, let’s review how bad multitasking is.

Researchers believe that there is a processing bottleneck in the brain. Essentially, we don’t have multi-core processors with multi-threading. In neurological terms, there are various functional components to consider. One is executive function, which is the “supervisor” function in the frontal lobes. Executive function includes the process of focusing attention, allocating resources, coordinating information, and scheduling cognitive tasks. Everything that the brain does is a finite resource, including executive function.

Attention itself is also limited. Our attention can be spread out so that we are taking in a lot of information at once, although very superficially. In this mode we may be scanning our environment for something interesting, or something in particular, but missing a lot of detail. Or we may focus our attention down on one thing, taking in greater detail but at the expense of ignoring everything else. This spreading out or narrowing down of our attention applies no only to sensory input but also ideas.

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Apr 12 2012

How to Lose Weight – Eat Less, Exercise More

There is an ongoing debate about the best strategies for long term weight control. I have repeatedly taken the position that, based mostly upon the clinical evidence but also what makes sense, that weight control is a matter of calories in vs calories out. The evidence consistently shows that exercise (increasing calories out) is extremely valuable to overall health but also specifically to weight control. Calories in is the tricky part.

There is no question that reducing caloric intake is critical to weight control, and that all diets that result in weight loss have one thing in common – reduced calories. It is difficult to achieve sustained calorie control, however. There is the pesky problem of hunger. Our bodies are very effective at regulating our eating behavior, and generally oppose underconsuming calories to result in weight loss. It is very difficulty to consistently resist such basic urges as eating when hungry.

This difficulty is exactly why there are so many fad diets, diet products, and beliefs about how to lose weight. No strategy works well, and I don’t have the magic answer, but we can look at the data we do have to see which strategies work better than the others. Recently a new study did just that, reviewing data from the 2001–2006 National Health and Nutrition Examination Survey (NHANES). This is a retrospective study based upon voluntary reporting, and therefore there are many possible sources of bias. The strength is that it is a fairly large study, looking at 4021 obese adults, and the result are reasonably representative of the general population in the US.

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Apr 11 2012

Tennessee “Monkey Bill” Update

I wrote two weeks ago about the latest state bill attacking the teaching of evolution, this one in Tennessee. This particular bill has perhaps attracted more media attention than other similar bills because Tennessee was the location of the famous Scopes Monkey trial. At the time the bill had passed the state house and senate, and we were awaiting the decision of Governor Bill Haslam on whether or not he would sign the bill.

Now our waiting is over. Haslam did not sign the bill, but neither did he veto it. He allowed the bill to pass without his signature.

I had speculated that perhaps Haslam was looking for a politically acceptable (for Tennessee) justification for vetoing the bill, as he stated publicly that the bill might represent legislative intrusion into an area reserved for the board of education. It now seems that speculation was overly optmistic, but not entirely without merit. Haslam indeed did not want to appear to be supporting the bill, but also did not want to veto a bill that is apparently popular in his state. About his decision he has officially stated:

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