Archive for March, 2009

Mar 31 2009

Microdynamos and the Piezoelectric Effect

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In our increasingly electrified world the race is on to find new sources of energy and batteries to store that energy. Applications range from the very small to the huge. The electric car industry is essentially waiting on improvements in battery technology.

Researcher Z. L. Wang from the Georgia Institute for Technology has recently announced a breakthrough at the other end of the size spectrum – the very tiny. He has created, not a battery, but a nanoscale energy generator that uses the piezoelectric effect to convert movement into electrical current. The effects are still modest – 0.2 volts with an efficiency of 6.8%, but this is enough for some applications.

The piezoelectric effect is a property of some materials that converts mechanical energy into electrical current. Our bones have this property and it is that which causes the molding of bones under pressure (such as moving the placement of teeth in the jaw using braces).  The amount of current generated is generally small – we won’ be running our cars off the piezoelectric effect, but in the aggregate can be useful.

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Mar 30 2009

Another Reason To Play Video Games

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I will reveal my conflict of interest right upfront – I love video games, I have played them all my life, and I still play regularly. Take that for what it’s worth.

That is partly why I am interested in news items, like this one about a recent study that shows that playing certain kinds of video games correlates with improved visual ability.  Researcher Daphne Bavelier compared the visual ability of groups of subjects who were made to play various types of video games. In the active group the video games were action oriented – Unreal Tournament 2004 and Call of Duty 2. In the control group subjects played the same amount of The Sims 2 – 50 hours over 9 weeks.

Bavelier found that the active group had a 58% improvement in a standard test of perceiving fine contrast differences – such as distinguishing fine shades of gray. This is a follow up study to a previous one by Bavelier where she found improvements between playing video games and not playing.

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Mar 27 2009

Magic in the Huffington Post

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In the Huffington Post yesterday Srinivasan Pillay informs readers about the Science of Distant Healing. Although Orac professed some (perhaps for dramatic effect) surprise that the HuffPo has sunk to such pseudoscientific depths, I confess I was not surprised. This is on a par with the antivaccinationist crankery that has found a home at HuffPo and the occasional Chopra nonsense. Any publication with the lax journalistic standards that would allow such rabid antivaccinationist nonsense to be published under its banner is capable of almost anything.

What Pilly is now offering is the claim that distant healing effects are real based upon poorly referenced and cherry picked data, abject naivete as to the nature of research, and the usual handwaving explanations invoking (or course) quantum mechanics.

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Mar 26 2009

Brain on a Chip

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Work continues to develop computers which more closely simulate brain activity. As I recently discussed, the brain is not a computer, and computers are not brains. But since brains operate by physical laws, there is no theoretical reason why we could not design a computer to function like a brain.

There are two types of approach to this – virtual brains and hardwired brain-like computers. The former approach uses conventional computer hardware to simulate a virtual brain. This project is far from achieving this goal, but programmers have already achieved significant milestone, such as the simulation of a cortical column of 10,000 neurons and 30 million connections.

The advantage of the virtual approach is that brain structure can be simulated directly without worrying about having to engineer functional neurons or their connections. The downside is that virtual brains require much more processing power than the brains they simulate. So virtual brains run incredibly slowly. It will likely still be 2-3 decades before raw computing power reaches the level where a desktop computer will be able to simulate a human brain in real time. (I am just talking about raw power here, not the knowledge to actually pull off the simulation.)

The advantage of the hardwired approach is that you end up with a processor that is much faster than a biological brain. The challenge, however, is in building something in silicon (or whatever) that acts like biological neurons in all the important ways.

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Mar 25 2009

Some UFO Logical Fallacies

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Reader “Gimble” left a comment on an old post of mine that was full of typical anti-skeptical logical fallacies so I thought I would have some fun taking it apart. The entry is on UFOs and the Argument from Ignorance. He begins:

It’s difficult to take your article seriously when it is chock full of unoriginal and regurgitated errors.

1. “There isn’t one unambiguous photograph or video that holds up to scientific scrutiny”.

What is your source on this? There are many photographs and videos that show no sign of tampering or fraud. What sort of “scientific scrutiny” would you require for a photo to be genuine? If it wasn’t proven to be digitally altered, you would claim it was a model or an item thrown into the air. In short, there is no photo in the world that cannot be debunked, but your statement that no unambiguous photo or video holds up to scientific scrutiny is blatantly false (what you are really saying is “if it is a photo of a flying saucer, then by definition it is a fraud”).

No, that is not what I am saying at all. Gimble here is trying to shift the burden of proof – make it my job to prove a negative, the absence of compelling evidence. Rather, if Gimble wishes to claim that there is an unambiguous photograph or other piece of evidence that has survived careful scrutiny – name it.  He didn’t, he just vaguely claims that they exist.

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Mar 24 2009

Cold Fusion After 20 Years

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This week the American Chemical Society’s national meeting will include presentations on low energy nuclear reactions (LENR). That is the new name for what is known in popular culture as cold fusion – the production of energy from nuclear fusion as room temperature or other low temperatures.

Cold fusion made its first big splash 20 years ago this week when Martin Fleischmann and Stanley Pons held a press conference in which they claimed that they had created energy from cold fusion in their lab. Their announcement was met with both excitement and skepticism. The skepticism, it turns out, was justified as in the years following no one has been able to replicate the alleged cold fusion of Pons and Fleischmann, including them. They spent years in a French lab trying to replication their effects and failed.

The excitement is easy to understand, as is a resurgence of interest. Energy is the primary limiting factor of civilization and quality of life – energy use tracks very closely with material quality of life. The expense of energy is part of the expense of almost all goods and services. And right now we are facing concerns over the environmental impact of our energy infrastructure. A source of abundant, cheap, clean, renewable energy would solve a great many problems and be a boon to human civilization.

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Mar 23 2009

Academic Freedom in Texas

Published by under Evolution

Texas remains a battleground state in the clash between creationists and scientists over science education standards. This week the Texas Board of Education will vote on whether or not to replace the “strengths and weaknesses” language that existed in the state’s science standards for the last 20 years, but was removed this Winter by a narrow 1-vote margin.

The battle represents the latest strategy of creationists to either hamper the teaching of evolution or introduce creationist ideas into the science classroom under the banner of “academic freedom.” The basic concept is that teachers, students, and school systems should have the academic freedom to: teach both the strengths and weaknesses of scientific theories, use outside (unapproved) material in teaching their classes, and believe whatever they wish without penalty.

Academic Freedom

The academic freedom strategy is getting some traction. Americans are generally for freedom, and the bills and language used to promote their agenda with “academic freedom” may appear innocuous on the surface. This strategy is specifically designed to skirt the constitutional barriers to teaching creationism in public schools, and has yet to be tested on constitutional grounds.

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Mar 20 2009

The Brain and Chaos

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The brain is not a computer, as anyone reasonably familiar with both should know. There are many similarities – both store and process information. But the fundamental architecture and function of the silicon on your desktop and the meat inside your skull are very different. That is why computers which are merely scaled up in power and speed will not spontaneously become conscious.The computational paradigm offers some insights into how the brain works, but it is not enough. Neuroscientists are searching for deeper understanding of brain function, particularly how it relates to consciousness. For example, it is known that the brain is organized as a massively parallel processor. There is also the neural network model of brain organization which tries to understand the brain as a collection of overlapping patterns of connectedness (networks).

At the same time there is a modular model of the brain which tries to understand brain function as a collection of anatomically identifiable modules that each have a specific function and interact interact to create the net effect of both consciousness and subconscious processing. I think that the network model and modular model are not mutually exlusive but are each part of the picture.

Now a newly published paper in PLOS Computational Biology argues that the brain operates at a critical point between organization and chaos – a state previously described as self-organized criticality. This is more of a description of the dynamic function of the brain, rather than its organization, and again is complementary to the modular and network models.

Self-Organized Criticality

The concept of self-organized criticality (SOC) emerged out of physics, mathematics, and efforts to understand complexity in nature. SOC explains how complexity can spontaneously emerge from simple interactions, such as individual cells interacting with each other. Such complexity would have various features. These include the property of being scale invariant – meaning that the overall structure of the complexity does not change significantly at different scales.

If that sounds familiar it’s because that is the defining feature of fractals described by Benoît Mandelbrot. As you scale up and down through a fractal pattern the amount of complexity remains the same.

Another feature of SOC is that it occurs at the critical point between ordered and random behavior, such as might exist between different phases of matter.

And a very important feature was described in 1987 by Bak, Tang and Wiesenfeld – that complexity in an SOC system emerges in a robust manner, which means it is not sensitively dependent on conditions. Therefore, the system can maintain its complexity even through great changes in the parameters of the system – the system does not have to be “finely tuned” in order for complexity to emerge.

What all this means is that a dynamic system, even one made of relatively simple parts with individual interactions that are also simple, can spontaneously generate complexity in a robust way – and exactly the kind of complexity we see in nature.

SOC and the Brain

Manfred Kitzbichler and his coauthors decided to look at brain function to see if it also has the features of self-organized criticality. They thought that SOC would be a good model for brain function because it optimizes information transfer, memory capacity, and sensitivity to external stimuli.

They looked specifically to see if brain complexity exhibits the feature of scale invariant complexity – if patterns in the brain are similar across scales of space and time. They examined a phenomenon known as phase coupling – essentially different parts of the brain firing in synchrony, presumably because they are part of a functional network – and measured how this coupling changed over time.

What they found is that this feature of brain activity does indeed have the signature features of self-organizing criticality.

Of course, this is an extremely complex topic and no one study such as this will be the final word. But they do appear to have provided the first direct evidence of SOC in the overall dynamic function of the brain.

If further investigations support this conclusion then this new way of looking at brain function is likely to deepen our understanding of what is perhaps the most complex system studied by science. This might also help us one day design computers that are more like human brains. Perhaps what this means is that such computers will have to be “grown” not built – they will also have to have complexity emerging out of self-organization, functioning at the edge of chaos.

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Mar 19 2009

How To Argue

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Arguing is one of those things most people do but few people do well. Many do not understand what a logical argument even is or how to do it correctly. Yet arguing is an essential skill of critical thinking. How we argue reflects how we think, how we evaluate our own conclusions, and how we challenge the beliefs of others.

Even the very purpose of arguing is often misunderstood. I have arguments almost every day. This does not mean I verbally fight with others on a daily basis, but rather I have discussions that involve either attempting to convince another of a specific conclusion, or resolving different conclusions on a factual matter. In most of the arguments that I find myself the other person has staked out a position and they defend it jealously, as if they were a high-paid lawyer defending a client. This adversarial approach, however, is not constructive. Rather, the parties of an argument should be trying to find common ground, and then proceed carefully from that common ground to resolve any differences.

The beauty of a logical argument is that it is, well… logical. It is, in a way, like mathematics. In math 1+1 must =2. If there is a disagreement about this, it can be resolved objectively and definitively. If two people doing the same math problem come up with different answers, how should they respond? Should they each defend their answer at all costs. Or, should they exam each other’s solution to see if one, or both, might contain an error, and then resolve the error to see what the correct answer is?

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Mar 18 2009

Don’t Take Medical Advice From The Pope

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While visiting in Africa Pope Benedict made his first public comment on condom use.

“(HIV/AIDS) is a tragedy that cannot be overcome by money alone, and that cannot be overcome through the distribution of condoms, which even aggravates the problems.”

The Catholic health minister warns that HIV can pass through condoms and therefore they basically don’t work.

It’s not difficult to point out the obvious here. The evidence shows that, when used properly, condoms decrease the risk of HIV transmission by 90%. The Pope and the Catholic church has an obvious conflict here as they have had a longstanding policy against condom use on moral grounds.

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