February 2009 Meeting: Dr. Anne H. Weaver on "The E-word: Teaching Evolution in the Land of Enchantment"

Anne H. Weaver, Ph.D. (author of The Voyage of the Beetle) spoke on "The E-word: Teaching Evolution in the Land of Enchantment." at our February 11th meeting, a celebration of Charles Darwin's 200th birthday (Feb. 12th). Starting with some recent education statistics, Anne showed that acceptance of evolution is lower in the USA than in all other developed countries, except for Turkey. Anne found that 18% of New Mexico 4th graders achieve proficiency in science compared to the national average of 27%, and that 18-19% of New Mexico 8th graders achieve proficiency in science compared to the national average of 27%. Dr. Weaver also showed that science comprehension falls markedly between 3rd and 8th grades.

When the question "What is the Scientific Method?"was asked of Santa Fe's Prospective School Board Members, the answers revealed a striking lack of science literacy:

"Ha. That's a good one. (Long pause.) The scientific method. I would guess that it would be deductive learning: being able to break it down, follow a formula." (Martin Lujan, Incumbent Board President, 8 years on School Board);

"Ok, well, the scientific method would be a method where you look for the facts, if I remember from elementary school. That's about as close as I can get to that. I haven't been to school since 1976." (Frank Montano, Incumbent)

"Any answer would be too much of a guess. I'm running for oversight and management and leadership, not professional education. That's not our mandate, as far as board members go. So you can say my answer is 'N/A.'…" (Peter Brill, running in District 5).

Anne described what factors correlate with student proficiency: monolingual cultures, societal attitudes and expectations, student self-confidence, availability of adequate resources, teacher preparation, unified curriculum aligned to clear standards, and an emphasis on principles and core ideas. As to the importance of evolution in science, Dr. Weaver cited Scott & Branch, 2008: "A teacher who tries to present biology without mentioning evolution is like a director trying to produce Hamlet without casting the prince."

Anne talked about how religious beliefs figure into the "debate," and discussed the Discovery Institute's "Wedge Strategy." The new terms being used by "Intelligent Design" advocates now include "both sides," "critical analysis," "strengths and weaknesses," "fairness," "academic theory," and Intelligent Design "theory." Anne showed that the policy of the state of New Mexico is strongly worded against allowing Intelligent design. Anne then moved beyond the question of religion to the broader question, why is creationism popular with children, even those of free-thinking or atheist families? She identified several onceptual "Sticking Points": naïve creationism, naïve essentialism, and naïve attribution of intentionality. Speaking of how children learn, she said that children's explanations for life's origins are usually one of these: creationist, spontaneous generation, or evolution. In fundamentalist communities, creationist responses predominate in every age group ; but even in in nonfundamentalist communities, the youngest children (Grades K-2) favored creation and spontaneous generation in equal numbers; the middle group (Grades 3-4) favored a creationist explanation; and the older group (Grades 5-7) and the adult group favored creation and evolution equally. Anne said the root cause was the notion of "Essentialism" - "…children …[treat] members of a category as if they have an underlying "essence" that can never be altered or removed. Essentialism … may even discourage children's learning of evolutionary theory…" (Gelman, 1999)

How can we reach these children? We need to find innovative and interesting ways to get the kids to grasp the fact that Individuals Vary; Populations Evolve. Anne described some engaging acting-out methods for teaching about variation. An audience member described a lesson in which a big bowl of candy corn mixed with M&Ms was passed around, with instructions not to eat the candy corn. After many rounds, there will still be some M&Ms -- the yellow and red ones, which camouflage well with candy corn.

NMSR thanks Anne Weaver for a splendid Darwin's Day talk. The annotated bibliography of her sources is posted on the NMSR Web Site. Check out her book, "The Voyage of the Beetle" (UNM Press).

1. Graph showing Acceptance of Evolution by Country: Miller, J.D., E.C. Scott, and S. Okamoto, Public Acceptance of Evolution. Science, 2006. 313 (5788): p. 765 - 766.
2. Early acceptance of natural selection theory in America: Humes, E., Monkey Girl: Evolution, Education, Religion, and the Battle for America's Soul. 2007: Ecco. (p. 47)
3. TIMMS Scores for 4th and 8th graders: Average Science Scores of Fourth- and Eighth-grade Students, by Country: 2007, U.S. Department of Education. National Center for Education Statistics, Editor. 2007. http://nces.ed.gov/timss/table07_3.asp
4. NAEP (Nation's Report Card) Scores for 4th and 8th graders: Student Percentages at NAEP Achievement Levels: Performance of NAEP Reporting Groups in New Mexico: 2005, U.S.D.o.E. National Center for Education Statistics, Editor. 2005. http://nces.ed.gov/nationsreportcard/pdf/stt2005/2006467NM8.pdf
5. New Mexico Standards Based Assessment Results: Change in Student Proficiency, School Years 2004-2005 to 2006-2007, Assessment and Accountability Division/Information Technology Division/NM Public Education Department. Department, Editor. 2007.
6. Religious Affiliation in New Mexico: U.S. Religious Landscape Survey: Religious Affiliation: Diverse and Dynamic (PDF), PEW Forum on Relilgion and Public Life. 2008, PEW Research Center.
7. Creation-Evolution Continuum: Scott, E.C., The Creation-Evolution Continuum. National Center for Science Education, 2008. http://ncseweb.org/creationism/general/creationevolutioncontinuum/
8. How Students Learn Science in the Classroom: Donovan, S.M. and J.D. Bransford, Eds., How Students Learn Science in the Classroom, Board on Behavioral, Cognitive and Sensory Sciences and Education, Behavioral and Social sciences and Education: National Research Council.
9. Cognitive factors in Creation & Evolution beliefs: Evans, E.M., Cognitive and Contextual Factors in the Emergence of Diverse Belief Systems: Creation versus Evolution. Cognitive Psychology, 2001. 42: p. 217–266.
10. Concept Development in Preschool Children: Gelman, S.A., Dialogue on Early Childhood Science, Mathematics, and Technology Education: A Context for Learing: Concept Development in Preschool Children, AAAS. 1999.
11. Recommended Reading: Weaver, A., George Lawrence, Illustrator. The Voyage of the Beetle. 2007, Albuquerque: UNM Press.
12. Further Reading: Weiner, J., The Beak of the Finch. 1995, New York: Vintage Books.

November 2007 Meeting: Dr. Gary Overturf on "The Issue of Thimerosal in Vaccine: The Science and the Hysteria"

Dr. Gary Overturf is a professor of Pediatrics and Pathology at the University of New Mexico's School of Medicine. He spoke about the hysteria that has developed in some circles regarding the alleged causation of autism by mercury-based disinfectants in vaccines at NMSR's November 14th meeting.

Gary mentioned a creationist he got in an argument with over 50 years ago, in Deming, NM. "People who want to believe, will," he said. He added that the same thing is happening with today's autism/vaccine scares, and warned that some 50,000 potential lawsuits may actually end up destroying many vital health programs. Vaccinations are the Number 1 medical success story of the 20th century, he said. In the United States in the early 20th century, there were almost 200 thousand cases of diphtheria annually. In 2001, however, the number of cases in that year numbered just two. Similar successes have been obtained for smallpox, pertussis, tetanus, measles, mumps and many more diseases.

Dr. Overturf then turned to toxins in the environment. "Everything, organic and non-organic, is potentially toxic! Even water or bovine milk are toxic enough and lethal if given in high enough dose," he said. Besides dose of toxins, other key factors include variations in animal or plant species, available metabolic pathways, and the duration and routes of exposure. Mercury, for example, can be absorbed into the body by inhalation, ingestion, skin contact, via intravenous treatments, or by injections. By far the most important consideration, he said, was "Dose, Dose, Dose!!!" Toxicity is most directly related to the dose of the toxin.

Mercury can be found in both inorganic and organic forms, he said. Inorganic mercury occurs in elemental or metallic forms, or as mercurous or mercuric salts, whereas organic mercury occurs in carbon-bonded compounds such as ethyl and methyl mercury. At high doses, mercury and mercuric compounds are well established nephro-toxins (affecting kidneys) and neuro-toxins (affecting the nervous system). He said that neurodevelopmental effects have been demonstrated at low doses, but only for pre-natal exposures, not for post-natal exposures. It's difficult to perform controlled mercury-exposure experiments on humans, because we know it's indeed toxic at high doses. If metabolized, both forms of organic mercury (ethyl and methyl) affect the kidneys, whereas direct exposure to organic mercury has the most effect on the central nervous system. Mercury can inhibit protein synthesis, which is why it's a problem in kidneys.

Thimerosal, a thiosalicylate salt of ethyl mercury, is used as a disinfectant on some vaccines. It is about 50% mercury by weight, but is added to vaccines in concentrations of just 0.003% to 0.01%. An average dose of mercury as a preservative in vaccines is around 17 µg (micrograms, millionths of a gram), about as much mercury as is found in a 5 to 6-ounce can of tuna. In cases where mercury treatments on bread and rice did cause severe health problems, the exposures are on the order of 2 to 3 milligrams (thousandths of a gram) per kilogram of body weight, or about 200 milligrams (or a fifth of a gram) for a 70-kilogram adult.

Before thimerosal was removed from infants' vaccines in 2000 because of concerns for its possible effects on infants, the typical series of vaccinations given in the first six months of an infant's life resulted in a total exposure of 100 to 200 µg of mercury. Of four agencies having requirements for exposure limits, three allowed this much, with room to spare (the Agency for Toxic Substances and Disease Registry, ATSDR, under Health and Human Services (HHS) and the Center for Disease Control (CDC); the Food and Drug Administration (FDA); and the World Health Organization (WHO). While these organizations were worried about infant 6-month exposures to over 300 or 400 µg of mercury, only the Environmental Protection Agency (EPA) had a guideline of under 200 µg, specifically 106 µg. Because of EPA's concerns, thimerosal was eliminated from infant vaccines in 1999.

Something else has changed in the last few decades, and that was the very definition of autism itself. The old diagnosis of autism was expanded to include several disorders, now collectively called Autism Spectrum Disorders (ASD). There is considerable overlap between ASD and retardation; for example, Fragile X syndrome, normally the most common cause of mental retardation, is now found to also be associated with ASD. Because the definition of "autism" was expanded, the reported incidence of autism increased, and ASD is now found in about 6 individuals per thousand (or 1:166). Other diseases now associated with ASD include tuberous sclerosis, PKU, Rett syndrome, Smith-Lemili, and Opitz syndrome.

While many of the conditions related to the onset of ASD have been identified with environmental exposures to the fetus in the womb, especially in the 2nd trimester of pregnancy, no data have shown that children with ASD have increased environmental exposure to mercury. In fact, Dr. Overturf said that the incidence of autism has continued to "increase" over the last seven years, despite the removal of thimerosal in vaccines during this time interval. Only one paper, published in Lancet in 1998 by A. Wakefield et. al., supports a thimerosal/autism link, and this paper has since been retracted by the journal and all of the authors except Wakefield. Because the Wakefield study has been vigorously championed by several well-intentioned (but misguided) special interest groups, a large segment of the population (over 50% of parents surveyed) believes that thimerosal preservatives do produce autism in infants.

Several other studies have provided evidence against a relationship between thimerosal and ASD, including large studies in the United Kingdom (Andrews N. et. al. & Heron, J. et. al., Pediatrics 114, 2004, with 109,863 children studied over 1988 to 1997), California (JAMA 2001; 285:1183-1185), a CDC study on 124,720 infants (phase 1) and 16,717 children (phase 2 re-evaluation) (Verstraeten T., et. al., Pediatrics 112:1039, 2003). The latter study found "… no consistent significant associations were found between thimerosal-containing vaccines and neurodevelopmental delay." The National Academy of Science has done three detailed studies (two in 2001, and another in 2004), again showing no linkage between thimerosal and ASD.

Professor Overturf concluded by stating that in the future, some other toxin, perhaps even one with some form of mercury, may be found to be associated with higher levels of ASD; however, many thorough studies have firmly shown that thimerosal vaccines are not responsible. The "alarming" increase in autism is not due to increased exposure to toxins in the environment, but rather to the re-definition of ASD itself.

A lively Q&A session followed. Asked about radio commercials for a Santa Fe doctor claiming to have cured autism with hyperbaric oxygen therapy, Gary said the only medical application for such therapy is for scuba-diving accidents, and that there is no "magic cure" for autism, which often is associated with genetic factors.

NMSR thanks Dr. Overturf for a splendid presentation.

July 2006 Meeting: Dr. Al Zelicoff on "One Flu out of some Cuckoo's Head: Why Pandemic Influenza isn't a problem (unless you are a chicken).

Al Zelicoff, a physicist/physician formerly at Sandia, spoke on "One Flu out of some Cuckoo's Head: Why Pandemic Influenza isn't a problem (unless you are a chicken)."

Al began by asking "What are the major international disease problems?" He identified Biological Weapons (a special problem), Pandemic influenza (not this time), and novel diseases (Hantavirus, Pertussis, Anthrax, etc.). He wondered "Why do we always get it wrong? And what can we do about it?" We gave "gotten it wrong" on numerous occasions - SARS, Monkeypox, Anthrax, Influenza shifts, and Tularemia, to name a few. And that's the ones we know about - what else is there? Why do we get it wrong? It's a combination of no data, bad science, poor statistical understanding, and failure to learn from history, Al said. He decried the lack of awareness of statistics among many medical doctors, who often generalize a few observations of a particular syndrome over their careers into "In case after case after case..."

The recent Bird Flu Pandemic Scare was officially kicked off by a cover story in Foregn Affairs magazine. With the words "The Next Pandemic" in huge red letters, the accompanying articles by Laurie Garrett got major media all excited about the imminent "pandemic." Al noted that a "pandemic" means global distribution of a disease, and not necessarily the disease's severity. Al proceeded to explain why the present threat is nothing like the 1918 Spanish Flu, which killed millions.

Zelicoff first described influenza nomenclature. Take the cryptic name A/ Hong Kong/ 68 (H3N2) - what do all the tags mean? For Flu, the Type is referred to by letter (A in the example), the location where identified is next (Hong Kong), followed by the year identified (68) and the "subtype" (H3N2). This last is key to understanding why the pandemic isn't what it's been cracked up to be. The "H" in the subtype refers to Hemagglutinin, a protein that binds the virus to the surface of a respiratory cell, attaching to cialic acid residues. These help the virus invade cells. The "N" stands for Neuraminidase, which cuts the bonds with H, and allows the virus to escape the cell, ready to infect another.

The common wisdom is that only immune system responses (antibodies) to the "H" proteins provide protection, and thus new antibodies are needed for each "H" variant. Thus, immunity to the Spanish Flu virus of 1918 (H1N1) would be useless in the presence of the new "Bird Flu" (H5N1). That common wisdom turns out to be wrong, fortunately for us! If someone has immunity to H1N1, and is exposed to H5N1, that virus will be blocked by the immune system as it tries to escape infected cells. People with antibidies for H1N1 will be protected from H5N1.

Zelicoff described Flu Pandemics over the last century. The big one, the 1918 Spanish Flu, was an extreme case, exacerbated immensely by the extremely crowded conditions in war hospitals, trenches, and so on.

In uncrowded conditions, a virus that agressively attacks and kills its host will be left alone to die before it can find a new host. Thus, uncrowded onditions favor non-aggressive strains of virus. But if conditons are very crowded, agressive strains can find an advantage: as the victim coughs his dying breaths, he can infect those next to him, and so on. Crowded conditions like the abysmal mass hospitals of World War I actually selected for more virulent and deadly strains.

Since 1918, several flu strains have impacted the world: H0N1 in 1933 (no pandemic), HxN1 in 1947 (no pandemic), H2N2 in 1957 ("Asian Flu", moderate pandemic), H3N2 in 1968 ("Hong Kong" flu, mild pandemic), and again in 1976 (Fort Dix, no pandemic). H1N1 returned in 1977 (the "Russian Flu," and was pandemic, but mainly for those under age 25 - i,e, those who had never been exposed to H1 or N1 in their lifetimes. In 1996, H5N1 ("The Bird Flu") appeared, and has not been pandemic. In 1998, H7N7 and H9N9 appeared (but no pandemic).

The threat to humans from H5N1 is small. Many have immunity by virtue of previous exposure to N1; millions have developed new immunities to H5N1 itself. The real threat of H5N1 is to chicken populations, which are held in crowded pens rivalling any of the horrors of WWI.

Because of the way chickens are often housed, for them, the Bird Flu is a serious threat indeed. But the hype about a human pandemic is extremely overblown, and detracts from truly important problems.

One reason for the "Sky is Falling" panic is that some felt we're "overdue" for a new pandemic. But looking at the actual data shows that no predictable pattern of pandemic periodicity exists. Other beliefs behind the "Bird Flu" hysteria include fears of an antigenic shift in the "H" gene, perception that there's a lack of antibodies for "H5", and insistence that antibodies to H5 are required for protection. Since some humans have gotten ill with H5N1, and since travel is widespread, we're two-thirds of the way to the pandemic, or so the story goes. Instead, immunity to H5N1 is already spreading through human populations. [On August 1st, 2006, Al sent word that "A CDC study released on Monday (8-1) 'suggests it might be more difficult for the deadly avian fly birus to spark a pandemic than originally feared.'"]

We should be scared of outbreaks of certain old (and new) diseases, Al said. We've done a miserable job on diseases which turned out to have very little impact, like SARS, but only with lots of luck (and some key observations by Dr. Bruce Tempest) was a serious outbreak of Hantavirus avoided right here in New Mexico. Then there was the case of detection of Tularemia in Washington, D.C. on Sept. 24-25, 2005. This was followed by reports of pneumonia in people who had been on the Mall in protests on those days. But, there was no surveillance, no phone calls to hospitals (nearby or out-of-state), and sloppy diagnoses. We don't have a clue what happened.

What we need, Al said, are some political and international agreements, some technological solutions, and some simple public health solutions. Monitoring is key. Al's company has developed a system, SYRIS, that is being used in Texas to create real-time communication between public health officials, private and public physicians, and (very importantly!) veterinarians. SYRIS simplifies the reporting process - it's only used on a very few patients exhibiting unusual symptoms, but when it's needed, it only takes 15 to 30 seconds for a report to be filed. SYRIS allows these data to be tracked in real time, and provides alerts to doctors if required.

Al summarized his points by stating that novel diseases are a certainty, are unpredictable, and usually associated with animals; we need better models for spreading of diseases, even common ones; international cooperation is needed; and real-time, geographic-based data collection is very much needed.

NMSR thanks Al Zelicoff for a stirring presentation.

January 2005 Meeting: Brian Sanderoff on "The Science of Polling"

At the Jan. 12th meeting, NMSR heard Brian Sanderoff of Research and Polling, Inc., on "The Science of Polling." Sanderoff's group does polling for the Albuquerque Journal, KOAT TV7, and many other groups. Polls can cost anywhere from 8 to 15 thousand dollars, and up to 35 thousand for advanced political efforts. Research and Polling, Inc. (hereafter R&P) has about 30 full-time pollsters, and sometimes also needs external phone banks of up to 200 callers, depending on demand.

R&P does some qualitative work (like focus groups), but mainly performs quantitative polling. The latter can be done by telephone, door-to-door, by mail, or by the internet. Each method has its own pro's and con's. It's easy to generate a large, random sample with telephone surveys; high response rates can be achieved, and sampling error can be calculated precisely. The phone format allows for top-of-mind image or awareness questions also, but has its own problems (telephone poll burnout, for one). For polling about things like job satisfaction, however, self-administered mail surveys can have some advantages. Respondents can be anonymous, everyone in the Universe (e.g. the Corporation or Division, etc.) can be polled, answers can be written out leisurely and thoughtfully, issues can be ranked, written responses may be more candid, and so on. This method works best when the Universe being polled has a vested interest in the endeavor (such as a hospital's physicians). Internet polling can have very fast turnaround times at very low costs, but are less reliable because of non-random sampling bias, self-selection bias, and the representativeness of the "sample." For example, the answers to the question "Do you Google?" will be very different in an Internet poll than in a random telephone survey.

Brian explained how the "plus-or-minus" figures given for errors in polls depend not on the population size, but on the sample size instead. It's not the size of the Universe (New York City versus Rio Rancho), but the sample that counts. The basic principle is shown in the figure below.

Poll accuracy depends on sample size, not on population size. If both of the two different-sized populations of colored balls above (one million versus 10 million) have the same proportions of colored balls, then samples of 400 balls drawn from either the one or the 10 million containers will be similar in proportion of colors. Using less than 400 in a sample would increase the polling error, and more than 400 would decrease it. However, the polling error in a sample of 400 is the same if that sample is from tiny little Torrance County or from the whole United States, given reasonable polling conditions.

Brian mentioned the simple formula that describes polling errors: for a 95% Confidence Interval (meaning that you get a wrong result only once out of 20 trials on average), the Standard Score is 1.96 standard deviations. For worst-case error, the expected split is 50/50 (use the last two presidential elections as examples). If the number to be sampled, N, is about 400, then the "Maximum Sampling Error" is SQRT(%For * %Against /N)*1.96 = v(0.5*0.5/400)*1.96 = about 4%. For N = 200, the error is ±7%, while for N=1000, the error is ±3%. If the decision is lopsided (say, 90%/10%, then the sampling error is reduced: for N=400, a 90% / 10% split would yield expected error of v(0.9*0.1/400)*1.96 = about 2.4%.

Brian spent a lot of time talking about polling problems, such as biases. Major biases include low response rates, under-represented demographics (like young adults with cell phones only), language, content, social stigma, respondent expectations, behavior versus attitude, and so on. There are various remedies for these biases, such as ensuring demographic quotas, multiple callbacks, and so forth. Cell phones, the Internet, and the "Do Not Call List" mindset are all changing the playing field of modern pollsters.

Sanderoff made exactly the right number of handouts (30), and predictions versus results were discussed for the recent general election in New Mexico.

In the Q&A, the importance of question preparation came up. Brian agreed that formulation of good questions was a key priority for a good poll. He also discussed "Push Polls," in which pollsters try to influence rather than test. While legitimate pollsters might ask questions like "Does X seem like an effective argument to you?", "Push" pollsters might say things like "Would you still vote for X if you knew he had a DUI? Was a child molester?"

A lively discussion ended the evening. NMSR thanks Brian Sanderoff for a fascinating discussion.

February 2004 Meeting: Professor Barbara Forrest, Darwin Day 2004

New Mexicans for Science & Reason (NMSR) hosted Professor Barbara Forrest (Southeastern Louisiana University, Department of History & Political Science ), on "Darwin Day 2004" The free meeting was held on Valentine's Day (February 14th), at the UNM Law Building, and was co-hosted by the New Mexico Academy of Science (NMAS) and the Coalition for Excellence in Science and Math Education (CESE). The meeting came two days after Darwin's actual birthday (Feb. 12th), so that our speaker could make the long trip from Louisiana over the weekend.

Barbara began by saying she was speaking to us as citizens, a role which unites all of us regardless of profession. By "we," she said, she meant citizens concerned with protecting public science education and church-state separation, those who value civic friendship instead of divisive religious politics, and those who regard secular, constitutional democracy as the protector of, not an obstacle to, personal religious freedom in whatever form chosen to exercise it. "We are people who will work hard to protect personal religious freedom, but will work just as hard to keep personal religious preferences from becoming public policy," she said, adding that Intelligent Design (ID) is very much a religious and political movement, and that its proponents are working to get their personal religious preferences enacted as public policy in the nation's schools. Barbara said this goal is called "teaching the controversy."

To explain why the discussion of ID needs to take a new direction, Prof. Forrest reviewed what the ID movement has not done, and also what they are doing. What they have not done, she said, was science. "The ID movement has produced no science in the twelve years since the Wedge's coalescence. Qualified scholars and working scientists -who have produced the science that Wedge scientists have never done-- have critiqued ID and amply demonstrated that it is not science. Indeed, the ID movement is not truly about science. Phillip Johnson confirmed this as early as 1996, when the ID movement formally organized as the Center for the Renewal of Science and Culture: 'This isn't really, and never has been, a debate about science. It's about religion and philosophy.' Johnson cites the Gospel of John as the biblical foundation of intelligent design."

Barbara also said that ID creationists demand equal consideration for ID as an "alternative theory" in the name of "fairness, but that "fair" does not necessarily mean "equal." And, she said, their demand ignores the point that teaching children real science is fair, whereas allowing them to be pressed into the service of the Discovery Institute's religious/political agenda is not. Forrest said we must therefore keep one spotlight focused on the fact that, after twelve years, ID is a scientific failure.

Prof. Forest discussed the underpinnings of ID "science" (irreducible complexity, empirical detection of ID, etc.), and also the leaders of this political movement (Phillip Johnson, William Dembski, Michael Behe, Jonathan Wells, and others from Seattle's Discovery Institute). She discussed the ID onslaught on school boards, and the use of clever buzzwords like "teach the controversy," "teach strengths and weaknesses," "teach objective origins," "teach the alternatives," "teach critical thinking," "academic freedom," and so on, all used to disguise ID's actual creationist foundation. Barbara discussed recent ID activity in Darby, Montana, and said that while ID creationists have always lost big, they spin everything as a victory and press ahead with their agenda anyway.

Prof. Forest discussed the underpinnings of ID "science" (irreducible complexity, empirical detection of ID, etc.), and also the leaders of this political movement (Phillip Johnson, William Dembski, Michael Behe, Jonathan Wells, and others from Seattle's Discovery Institute). She discussed the ID onslaught on school boards, and the use of clever buzzwords like "teach the controversy," "teach strengths and weaknesses," "teach objective origins," "teach the alternatives," "teach critical thinking," "academic freedom," and so on, all used to disguise ID's actual creationist foundation. Barbara discussed recent ID activity in Darby, Montana, and said that while ID creationists have always lost big, they spin everything as a victory and press ahead with their agenda anyway.

Barbara made a special point to forestall any thought that her position is anti-religious. "ID creationists constantly charge that if one is pro-evolution, one is also anti-religion, or that if one is for secular democracy and education, one is automatically against religion. This is a misconception of the word secular, she said. Many evangelical leaders are shifting toward the idea that "secular" means "anti-religious." "In their view, if an institution such as government or an academic discipline such as science does not explicitly incorporate religious belief, that institution must be understood as overtly hostile to religion. In short, secularism is rejected by people who want their religious beliefs sanctioned as public policy. But secular means non-religious, not anti-religious. Secularism is a political concept vital to constitutional democracy, and we must rehabilitate the concept as such in the public mind," she said, adding "The ID agenda is an anti-secular movement. It is another column in the Religious Right."

Barbara gave many examples of the religious underpinnings of the ID movement, including groups like Friends of the Family, the Eagle Foundation, and others. ID is one of many fronts in a "culture war" that is being waged by Religious Right fundamentalists. She stressed the exclusionary nature of the religious outlook of many ID leaders; for example, Phillip Johnson demonstrated ID's religious exclusionism by slandering the religious faith of Catholic evolutionary biologist Kenneth Miller: Johnson said "The only reason I have to believe that Kenneth Miller is a Christian of any kind of that he says so. Maybe he's sincere. But I don't know that. If he is, I can say this: you often find the greatest enemies of Christ in the church, even in high positions. There is a kind of person who may be sincere in a way, but is double-minded, who goes into the church in order to save it from itself by bringing it into concert with evolutionary naturalism, for example. And these are dangerous people. They're more dangerous than an outside atheist, like Richard Dawkins, who at least flies his own flag. So I am not impressed that somebody says that he is a Christian of a traditional sort and believes that evolution is our creator. This is, at the very least, a person whose mind is going in two directions, and such people often do a great a damage within the church."

In effect, the ID movement wants their strict, narrow view of God, as one who would never stoop to using evolution, to be mandated as official government policy. This is patently unfair - not just to atheists and agnostics, but also to the many religious people who believe evolution was simply God's method of creation. Barbara mentioned several intellectual believers who have found delight in reconciling their views of science and religion, such as evangelical Christian Keith Miller's new book, "Perspectives on an Evolving Creation." Barbara stressed that there need not be the type of conflict that ID is creating.

Prof. Forrest said that ID proponents are our fellow citizens, and under the Constitution they are entitled to their exclusionary religious views and their dislike of secularism. But, she said, they are not entitled to have those views enshrined as public policy.

Barbara concluded by reflecting on the long and successful marriage of Charles and ??? Darwin, and wishing everyone a Happy Darwin Day and Happy Valentine's Day. She closed with this, from Darwin's "The Descent of Man" : "Females . . . prefer pairing with the most ornamented males, or those which are the best songsters, or play the best antics; but it is obviously probable that they would at the same time prefer the more vigorous and lively males, and this has in some cases been confirmed by actual observation."

March 2003 Meeting: The Sci-Fi Channel Roswell Dig

New Mexicans for Science & Reason (NMSR) heard Dr. William Doleman (UNM, Office of Contract Archaeology) speak on "The Sci-Fi Channel Roswell Dig." The meeting was held on March 12th, 2003, in the NM Museum of Natural History and Science. Doleman was prominently featured on the Sci Fi Channel's November 22nd, 2002 airing of the documentary "The Roswell Crash: Startling New Evidence," hosted by Bryant Gumbel. (See the March/April 2003 edition of Skeptical Inquirer for Dave Thomas's review of the Sci Fi show.)

Bill Doleman (Photo by Dave Thomas, copyright 2003)

Doleman said he was a bartender and a free-lance writer before becoming interested in archaeology. His field, contract archaeology, accounts for 90% of all money spent on archaeological work. Many of the contracts involve federal mandates such as the Historic Preservation Act of 1966. Contract archaeologists study the cultural impacts of land development or government projects by determining if the land has any sites that might qualify to be on the National Register. Candidate sites may qualify based on location (such as battlefields), persons who lived there (Washington's home), crafts (such as pottery) or significance with regard to history or prehistory. Doleman mentioned Kennewick Man as an example of a far-fetched claim (namely that this man from many millennia ago is ancestral to Native Americans now living in the same area). UNM's Office of Contract Archeology (OCA) competes with several private outfits for contracts for what are essentially cultural equivalents of environmental impact statements.

In 1999, Doleman's group was approached by UFO researchers Don Schmitt and Tom Carey, and was asked how he would study a "UFO" site. Doleman laid out a budget for a small project, but it cost too much, and he didn't hear from Schmitt and Carey again for three years. Then, in 2002, they returned, this time with backing from the Sci Fi Channel. Doleman met with Larry Landsman, the Sci Fi Channel special projects director, and prepared a budget and test plan. The crew began field work at the purported Roswell crash site on September 16th, 2002, and stayed about 9 days. Attendee Ken Frazier asked if there had been discussion within UNM about being connected to "paranormal crap," but Doleman said there was nary a peep of discord until much later, when Target 7's Larry Barker began asking UNM officials about the OCA's involvement with the Sci Fi show. Doleman said he wasn't there that night to defend what the Sci Fi Channel did.

His team's goals were: o search for evidence of a low-angle impact by .. something; o use reported (anecdotal) observations to decide where to perform the search; o survey the site for debris, or a "furrow" or "gouge." The show advisors, Schmitt and Carey, chose the location for the "Roswell Dig." Doleman said author Kevin Randle also approved the location for the site. Doleman said the rationale for doing the dig was that they had a Contract. The Roswell "Incident" is culturally and economically important, both in New Mexico and world-wide. He said the bigshots at UNM said the work was appropriate.

Doleman said the incident should really be called the "Corona Incident," but that Corona didn't have a sheriff, and so Roswell got all the fame. But, until now, there hasn't been a search for real physical evidence. He said Schmitt and Carey were brave to put their ideas to the test. Two million people watched the show, and a sequel is planned, he said. For now, everyone's happy, Doleman said- Schmitt and Carey stay on the world's radar, MPH Entertainment gets a nice gold star, and UNM'S OCA gets paid.

Doleman talked a bit about archaeology as the forensic science of the past. Clues in sites today can tell archaeologists much about the past, such as whether the original inhabitants used stone boiling or pit roasting. The processes that shape sites can be divided into cultural (C-transforms) and natural (N-transforms). Had they found the remains of an Air Force balloon experiment, that would have been a C-transform.

What were the results of the Roswell Dig? Doleman said they were "more than I expected, less than they [Sci Fi Channel] hoped for." From aerial photographs, pre- and post-1947: there was no furrow. In the electromagnetic conductivity survey, there was no furrow. From the High-resolution Metal Detection Survey: no obvious debris. From Archaeological Testing (pits, soil samples, etc.), there was no obvious debris, 25 HMOU's (Historic Materials of Uncertain Origin), and 66 soil samples. Backhoe trenching provided one anomaly, a V-shaped feature that might have been a "furrow," but that mostly disappeared when scraped. Doleman said he's written this off "about 95%" now, but still.... There was also a soil stratigraphy study. An "alternative furrow" was found, but interest in this fizzled when it turned up on 1946 aerial photographs (from a year before the Roswell Incident). They also found a beat up old weather balloon, but one only ten or so years old, not fifty.

The "Furrow" (photograph courtesy & copyright 2003 William Doleman)

A lively question and answer session followed the talk. NMSR thanks Bill Doleman for an informative lecture.

See Also: Bait and Switch on 'Roswell: The Smoking Gun’

 

January 2003 Meeting: Molecular Evolution

New Mexicans for Science & Reason heard Dr. Rebecca Reiss (New Mexico Tech) on " Molecular Evolution: Studies in Microbes, Middens, and Man" at our January 11th meeting. Rebecca began by discussing her work on xenobiotics -- bacteria that can metabolize exotic compounds like the dangerous pollutants called dihalogens, which include ethylene dibromide (EDB) and ethylene dichloride (EDC). Reiss mentioned there are 175 sites with such pollutants in New Mexico, described with the acronym LUST - Leaky Underground Storage Tanks. In Reiss's pilot project, levels of EDB and EDC have been monitored at selected LUST sites in New Mexico, and the levels of these compounds have been seen to decrease over time. The best explanation is that it's biotic - bacteria are breaking down these dangerous compounds, and performing a valuable public service. But the rates are quite slow. How can science speed up this process?

That's where the two fields of genomics and proteomics comes in. Genomics is the study of DNA, the genetic material, and its RNA products. RNA, in turn, directs the assemblies of legions of amino acids into long chains called proteins, which are the molecules of both structure (like bone) and activity (like enzymes for digestion). The study of how the amino acid chains fold up and interact with other molecules is called proteomics. So, the question of understanding bioremediation of such compounds involves identifying the particular species involved (and many species of bacteria are lurking there), isolating the responsible genes, or isolating the actual proteins. Rebecca discussed PCR (polymerase chain reaction), which can be used to "amplify" tiny snippets of DNA into measurable amounts. This technique is very useful, but it has its pitfalls - for example, any contamination (DNA from, say, a human handler) can also be amplified to yield a false signal. Reiss's group has studied using 16SrRNA primers to isolate the xenobiotic genes of the dihalogen-consuming bacteria. Another approach is to study the proteins directly, but proteins can't be amplified like genes can with PCR. But, you can examine banded protein stains from pools of hundreds of bacteria, and perhaps even deduce the key proteins for the reaction. If you can, then duplication of the proteins in mass is quite practical. Also, the amino acid sequence can be converted into a DNA sequence, and appropriate DNA primers can be developed, which will lock onto the corresponding genes in the bacterial genomes. Besides the impressive biology, there are many difficult technical issues involved, such as filtering bacteria from solution, growing bacteria that refuse to be cultured, asnd so forth.

Rebecca also discussed work with middens (dung heaps near houses), and how molecular markers could assist with archaeological studies. She mentioned her work on human evolution and NUMTS (Nuclear-localized mitochondrial DNA's). Our cells have many mitochondria outside the nucleus, busy helping us get enough energy. But, occasionally the DNA from one of these energy powerhouses (which probably were a stand-alone microbe before their assimilation long ago into our eukaryotic cells) can migrate right into the nucleus, where its rate of mutation/evolution slows down. When we compare our DNA with that of other humans, or other primates, we can observe many different NUMTS, because this migration process is still ongoing. NUMTS can be used in forensic analysis; there are so many that comparison of several can indicate how closely related given test DNA is to that of an individual or group.

NMSR thanks Rebecca Reiss for a delightful presentation.

 

 November 2002 Meeting: Structure of the Universe

Trish Henning

New Mexicans for Science & Reason heard Associate Professor Trish Henning (UNM, Director, Institute for Astrophysics) on "The Structure of the Universe." The meeting was on November 13th. Trish started by mentioning the distribution of mass. Where is it? What is the difference between luminous mass and so-called "dark matter"? We can see nearby galaxies (Andromeda in the northern hemisphere, the Magellanic Clouds in the southern), and in the last few decades, we have learned quite a bit about the distribution of galaxies through the universe. One of the big surprises was the discovery of the local super-cluster about 50 years ago. Since then, better and broader surveys have been performed, revealing huge voids between clusters of galaxies.

From the 2dF Galaxy Redshift Survey, showing voids and structure over billions of light years

Trish talked about how the expansion of the universe is used to estimate position of galaxies from observed speed, which is given by the Doppler shift of galactic emissions. Because gravitational interactions can act against the motion of expansion (locally, at least), clusters of galaxies tend to get smeared out in Doppler-shift plots. Trish talked about the difficulty of seeing galaxies through the disc of the Milky Way, and how radiotelescopes use the hydrogen 21-cm line to penetrate galactic dust. She talked about ongoing galactic surveys, including the one she works on in Australia, and New Mexico's Sloan Digital Sky Survey. It looks like we're finally able to discern the scale of galactic clustering across the universe.

NMSR thanks Trish Henning for a delightful presentation.

   

October 2002 Meeting: Panel Discussion on the "Language Gene"

New Mexicans for Science & Reason heard a Panel Discussion featuring Distinguished Biology Professor Randy Thornhill (UNM), Retired Linguistics Professor Hank Beechhold, and Anthropologist Ted Cloak, on Implications of a New-Found "Language Gene" (re Svante Paabo's and colleagues' research on FOXP2). The October 9th meeting got started with a brief introduction by Dave Thomas. It all begins with an extended family (the KE family), half the members of which exhibit a severe hereditary language disorder. The disorder involves unintelligibility, trouble forming plurals, and more, and even shows up in physical brain scans. From genetic studies of family members, a gene, FOXP2, was found to be the likely culprit of this language disorder. Later, Paabo's team compared FOXP2 of unaffected humans and several other primates, and found that the normal human form of FOXP2 was different from that of chimps and the other apes, and other mammals as well. Earlier this year, FOXP2 was heralded as a "Language Gene" distinguishing man from the apes.

The first panelist, biologist Randy Thornhill of UNM, stressed that neither genes nor environment alone determine the development of traits, but rather the interaction of the two (the Interactionist Perspective). Both environmental determinism and genetic determinism have been tossed on the trash heap, he said. Evidence supports the now accepted Interactionist model, and so one can't consider any given trait as more environmental than genetic, and vice-versa. Language has important social causes, like learning, but it also has physical aspects involving muscles, vocal cords, and so forth. There was no question genes were involved before FOXP2's discovery, Randy said, it's that we didn't know which of the tens of thousands of genes affected language. And many genes are involved. The interesting question is not whether or not language is biological, Randy said; we knew that already! It is not whether evolution did it, but which evolutionary process did it. It could have involved direct selection for the trait or traits, or indirect ("coat-tails") selection. Genetic drift is out as an explanation because language is much too complicated. Language shows design, the hallmark of adaptation. It can be used to communicate, to deceive, or to manipulate. Because language involves multiple adaptations, Randy said, it clearly isn't due to indirect selection. Language is directly selected. We pay attention to it; it has become a Fitness Indicator. Randy mentioned his work on symmetry, and his view that facial and body symmetries are likewise fitness indicators. (This was the topic of our June 1997 meeting, and is reported in the July 1997 NMSR Reports). Thornhill also spoke to NMSR on biology and rape at our May 2000 meeting (June 2000 NMSR Reports).

Biologist Randy Thornhill

Panelist Hank Beechhold, a retired professor of linguistics, spoke about the origin of language. We don't know what form the first language took, he said. Some have speculated it developed from imitating animal sounds ("Bow-Wow Theory"), other sounds (:Ding-Dong Theory"), or perhaps grunts. Language is related to consciousness itself, Hank said, and consciousness itself is related to language. Hank's second point was that "language" is much harder to define than most people think. Communication? Even single-celled creatures communicate with their environment. Is language merely "A means of phonetic communication shared by groups of humans?" What then of writing, or signing? No, speech is simply one medium or channel, not language itself. Therefore, Hank said, language precedes speech, as competence precedes performance. While FOXP2 does affect speech, Hank said, there are undoubtedly many other genes involved. Hank mentioned an African gray parrot studied by Pepperberg, who found the bird able to actually communicate verbally at the level of a young child. It would be foolish to lay all language at the feet of FOXP2, but it's a player. Perhaps it was selected for some property like facial expressions after language and speech had appeared. Hank concluded by mentioning that adult Neanderthals had vocal tracts like those of young infants, and that their ability to articulate speech would have been quite limited. Was this related to Neanderthal extinction? Did Neanderthals have FOXP2? Is FOXP2 related to speech, or to language? (At this point, it was suggested that we might try to get some Neanderthal DNA and check it for FOXP2 differences.)

Linguistics professor Hank Beechhold

The final panelist, anthropologist Ted Cloak, commented that the panel was turning out to be more of a love feast than a hotbed of controversy. Like the other two speakers, Ted said FOXP2 is a language gene, but not the "language gene." Ted described the KE family, and the nature of their language disorders. One problem they have is generalizing about number, gender, or sex. For example, some words are easy to pluralize (dog, dogs), but others have special rules (sheep, sheep, or cow, cattle). The affected members of the KE family see every pluralization as a "special" case. They have to learn that dogs are the plural of dog, and also, that cats are the plural of cat, and so on for all nouns.

(At this point, someone suggested that people who had trouble with tenses or plurals, or maybe even those who say "nuke-u-lar," might soon be described as "FOXP2 challenged.") Ted discussed how the gene might have been changed by a selective sweep and fixation event, but that this hasn't been proved yet. What would happen if the chimp FOXP2 was somehow injected into a human? It wouldn't necessarily be the same as what happens in the KE family, because their genetic defect is a mutation of the working human gene, and might not be "chimp-like" at all. Of course, we can't put chimp DNA into a human child, so we'll have to figure it out some other way. Ted again emphasized that FOXP2 may be a player, but it's not the only one. Language is not a necessary precursor to culture; it arises as enhancements of culture. One of the first critical human capabilities was fine imitation. Ted's conclusion was that culture most likely preceded language, not the other way around.

NMSR thanks panelists Thornhill, Beechhold, and Cloak for a most interesting discussion.

March 2002 Meeting: Cody Polston & Bob Carter on Ghost Hunting

by Dave Thomas : nmsrdaveATswcp.com (Help fight SPAM!  Please replace the AT with an @ )

New Mexicans for Science & Reason (NMSR) heard Cody Polston and Bob Carter of the Southwest Ghost Hunters Association (www.sgha.net) speaking on "Hunting for Ghosts" on March 13th, 2002.

Cody Polston

Bob Carter kicked the evening off by saying that the SWGA group is interested in finding out what causes ghostly visions, even if there is a prosaic explanation. One of the possibilities they are looking at is that visions of specters might be caused by abnormal electromagnetic fields, as has been hypothesized by Michael Persinger. Cody Polston noted that photographs alone cannot prove ghostly visitations, and that even negatives can be faked. Cody mentioned that the group's bylaws prevent them from using psychics in their investigations, as you cannot use one paranormal phenomenon to validate another. This attitude has earned SWGA criticism from other ghost groups, which routinely employ psychics in their investigations. He described a curious incident they investigated in Texas, where cars left parked on a train track are mysteriously "pushed" out of harm's way, with small handprints visible in flour particles dusted onto the rear of the car. However, it's a gravity hill, and the motion of the car is no real surprise. Furthermore, the group found that when the flour is put on the car, it reveals handprints that were already there, made visible because of oils and residue left behind. This did not make them popular with the Texas ghost group.

The group does "investigations" once or twice a month, and employs some low-tech magnetic field sensors to look for odd fields. They typically measure from 5 to 40 Hertz only. Cody and Bob described some of the curious events they have observed, such as glasses blowing up at Maria Theresa's restaurant, flashing lights at La Placita, weird knocking at the Church Street Café in Santa Fe, and sliding chairs at Los Ranchos de Corrales restaurant. Cody noted that even if the group could prove that photographed "orbs" were real phenomena, it's still a big leap to prove they are ghosts.

All in all, it was a friendly encounter. Cody and Bob do think there may be something to ghost stories, and that's what keeps them going. But, they don't declare that every fuzzy blob in photographs is a "ghost," either. The group could use help with basic electromagnetics and ideas for sensors, if anyone wants to help out. Their investigations are open to those who want to tag along.

NMSR thanks Cody and Bob for an interesting talk.

 

February 2002 Meeting: Stuart Kauffman on Investigations

by Dave Thomas

New Mexicans for Science & Reason (NMSR) heard Stuart Kauffman of the Santa Fe Institute and BiosGroup speaking on "Investigations" on February 13th, 2002.

Kauffman is a biologist and former professor of biochemistry at the University of Pennsylvania and a professor at the Santa Fe Institute; author of Origins of Order: Self Organization and Selection in Evolution (1993), and coauthor with George Johnson of At Home in the Universe (1995). He talked to NMSR about his third book, Investigations.

Kauffman began by introducing the concept of "autonomous agent." Is a bacterium, which could be said to act on its own behalf as it gleans food from its environment, an autonomous agent? Stuart then gave his definition of such an agent: "A self-reproducing system that can do one thermodynamic work cycle." He raised and lowered a pen, illustrating a work cycle, and thus demonstrated his own status as an autonomous agent. The bacterium is also such an agent, of course. But something that reproduces without work, such as a crystal, isn't an autonomous agent. Even DNA is not an autonomous agent; it specifies order, but does not perform work cycles. Kauffman mentioned that Schrödinger predicted that life would require aperiodic crystals bearing a code nine years before the elucidation of the structure of DNA by Watson and Crick. Stuart said the question of what makes a cell alive is still open.

One of the perplexing problems of the origin of life (not to be confused with the subsequent evolution of diverse life forms over billions of years) is that DNA codes for proteins (strings of amino acids), but proteins are required to help copy the DNA. As yet, we haven't been able to make a molecule that makes copies of itself without the assistance of other molecules like proteins. It's hard to get RNA (ribonucleic acid) to duplicate itself, because too many G's and C's (guanine and cytosine nucleotides) make it fold up in knots. But it's probably not impossible, Kauffman said. He mentioned Gunter's research on a "cousin" of RNA, in which hexamers made copies of themselves without other proteins to assist. Stuart also mentioned work on a 32-amino-acid protein that breaks into smaller subunits (of 15 and 17 amino acids each), and how the subunits catalyzed the production of more copies of the 32-amino-acid sequence. He said this self-reproducing protein "blew the field wide open."

He went on to discuss systems in which components catalyze each other, but not themselves. If two molecules A and B can catalyze each other's formation, as has been demonstrated, why can't three? Or four? Or hundreds or thousands? Kauffman called such assemblages "autocatalytic systems." He talked about a button-and-thread model for self-organization, in which buttons and threads are strewn on a floor. Pairs of buttons are connected with the threads randomly. At first, most of the buttons are free; there are a few pairs, and even some triplets. But as more threads are added to given pairs, the number of interconnections rises steeply. Larger clusters are joined into still larger clusters, until BAM! - giant clusters are formed.

Kauffman then introduced the concept of "adjacent possible." If you have a bunch of molecules and reactions, what collection of molecules will exist after one reaction step? There are many possibilities, which constitute the immediate "adjacent possible." For example, once there were just a few organic molecules; but now, there are trillions. "The biosphere has expanded into its adjacent possible," Kauffman said. Additionally, the number of ways to make a living has exploded.

Stuart then discussed work cycles and energy. Work cycles are a way to link spontaneous and non-spontaneous reactions. For example, the hexamer (6-acid molecule) which catalyzes pairs of trimers (3-acid molecules) to form more hexamers performs work cycles. It "eats" energy (supplied as photons of light) and trimers, and produces more hexamers like itself. The process can oscillate back and forth, respond to feedback, and so on. Kauffman criticized the standard definition of work as force times distance, and says he prefers to define work as "the constrained release of energy." But where do the constraints come from? Who makes the pistons in Carnot engines? It takes work to make the constraints, and it takes the constraints to produce work. Work can be non-propagating, like shooting a cannonball into a field; while a hole and hot dirt are created, no useful work is performed. But arrange the cannonball to turn a paddle wheel as it zooms away, and that can be harnessed to, say, pump water and irrigate the fields. This is "propagating" work, he said.

In cells, the cells make lipids of different types that combine in layers, producing vital cell membranes; these are the "constraints" of the cell. And the cell makes copies of itself, providing closure. Kauffman said it's not just a question of matter, energy, or Shannon information: it is an organized system that propagates itself, a "living" state of matter and energy.

Unlike physics, in which the "adjacent possible" states of, say, atoms in a sealed vessel can be easily described, the biosphere is not finitely pre-describable. As an example, Kauffman discussed Darwinian pre-adaptations. We all have hearts, needed for pumping blood. But what if the heart could have another as-yet-unanticipated function? What if some one person's heart happened to be sensitive to vibrations typical of impending earthquakes, and that this ability caused the person to run to safety outside just before massive earthquales can strike? That person might have more descendants than others without sensitive hearts, and if there were many earthquakes, that ability might spread to many descendants. We can't possibly anticipate all the possible pre-adaptations, and so we can't even define the "adjacent possible." Stuart suggested that a possible "4th Law of Thermodynamics" for the biosphere is that it will expand into the adjacent possible as fast as it can get away with it. But Kauffman hasn't figured out how to mathematize it, because he can't even list all the possibilities.

A lively question and answer period followed the donut break. In response to one question, Kauffman cautioned that we don't really know for sure what will happen because of genetically modified foods, because we don't know for sure how those genes will interact with others in the field. Paul Gammill asked about teaching "Intelligent Design" in schools. Kauffman replied that design theorists have not made their case to biologists, and don't deserve equal time in schools, because the fact of evolution appears to be incontrovertible. Gammill proceeded with a laundry list of questions regarding chirality, complexity, and so forth. Kauffman said these questions included some very good ones, and he provided some good answers and areas for exploration. He said the Design Theorists need to identify their Designer if they expect to develop their theory as a science.

Stuart Kauffman concluded with a brief discussion of Maxwell's Demon, a hypothetical construct that could appear to violate the laws of thermodynamics by, say, allowing only atoms of a certain speed to go though a hole connecting separate containers, thus changing the state into one of disequilibrium. While no Demon can exist in the domain of atoms alone, it's different in the biosphere. There, Darwinian pre-adaptations can be "measured" by the biosphere (much as the Demon would measure an atom's speed), and adaptations that are favored in the environment can be "catalyzed." He concluded that "The biosphere keeps finding new ways to measure displacements from equilibrium, and how to get work from them."

NMSR thanks Stuart Kauffman for a mind-expanding talk!

 

November 2001 Meeting: An Insight Into Relativity

by John Geohegan

Einstein's Special Theory of Relativity (SRT) is generally misunderstood for several reasons. Most of us have no need to apply its principles, nor do we have any experience with objects moving at close to the speed of light. Even so, we would like to understand SRT. Popular explanations refer to moving objects gaining mass and shrinking in the direction of motion, and moving clocks running slow, but these explanations are referring only to appearances in much the same manner as statements about the sun rising in the morning, moving eastward across the sky, and setting in the evening. We accept that the sun appears to rise in the morning and we can calculate exactly when the "rise" will occur, but a more accurate and lengthier statement would deny that the sun truly rises and explain the appearance by referring to the rotation of the earth.

Just as the formulas for calculating the sun's apparent motion are likely to contribute nothing to understanding the reason for the appearances, applying the formulas of SRT really doesn't reveal why objects appear to contract and clocks appear to run slow. It's perfectly possible to apply the set of relativistic equations called the Lorentz transformation and obtain a correct numerical answer without having a clue as to why the equations work so well. This is number-crunching without insight.

The following example offers a simple way of gaining insight in relativity.

Imagine two space ships have just passed each other and at the moment of closest approach they have synchronized their clocks at 12:00. As they draw farther apart each sends out a flash of light precisely as his own clock indicates each hour. Brian will receive Alfred's 12:00 signal when his clock reads 12:00 because the signal has no distance to travel, but Alfred's 1:00 signal will be received at some time later than 1:00 depending on their relative velocity. To make things easy, suppose the velocity is great enough that Brian receives Alfred's hourly signals every two hours by his (Brian's) clock. SRT tells us that the same conditions will apply to Alfred; he will receive Brian's clock signals every two hours, at 12:00, 2:00, and 4:00 by his (Alfred's) clock.

Consider the signal sent out by Alfred at 1:00. It is received by Brian when his clock reads 2:00 and reflected back at the same time to be received by Alfred when his (Alfred's) clock reads 4:00. Not being able to see Brian's clock, Alfred calculates that the signal must have reached Brian at 2:30 (halfway between 1:00 and 4:00). If informed that Brian's clock actually read 2:00, Alfred might conclude that it was a half-hour slow, and thus we see what it was that Einstein discovered: measurements of time intervals depend upon relative velocity. Of course, if Brian sends out a signal when his clock reads 1:00, exactly the same values will be repeated and he will see that Alfred's clock is apparently running slow. Without the insight made possible by this simple example it's possible to misinterpret SRT as claiming that A's clock is running slower than B's at the same time as B's is running slower than A's.

The same example, slightly extended, can be used to explain the so called "twin paradox", which is not a paradox at all. If after traveling for two hours by his clock, Brian were to suddenly change to a return trip at the same relative velocity, he would start receiving signals at the rate of two per hour instead of one every two hours. On his two hour return home he would thus receive four more signals sent out by Alfred, arriving home just as Alfred was sending his 5:00 signal. Alfred would have aged five hours while Brian aged only four. This problem illustrates the relativistic nature of time intervals.

It must not be thought that SRT deals only with some sort of illusion. Einstein's theory unified electricity and magnetism and is tested every day for meaningful predictions. The Global Positioning System tests Einstein's predictions millions of times each day, worldwide, and reveals the magnificence and practicality of relativistic calculations.

The following images, by Dave Thomas, show how Doppler measurements of the binary stars in system Castor C (in the constellation Gemini) agree with Einstein's theory (speed of light is constant invacuum), but do NOT agree with the predictions of theories in which the speed of light depends on the speed of the light-emitting source.

Expected Time/Velocity Curve of One Star of Castor C (Binary System), if Einstein was RIGHT (Light travels at 299,792,458 meters/sec)

Expected Time/Velocity Curve of One Star of Castor C (Binary System), if Einstein was WRONG (Light travels at c=299,792,458 m/sec ± motion of source); here, Castor C is 5 light-years away. At orbital speeds of 0.0004c, transit times will vary from 5 lightyears/(1-.0004 )lightyears/year = 5.002 years = 1827.0 days,to 5 lightyears/(1+.0004)lightyears/year = 4.998 years = 1825.5 days, or about 1+1/2 days.

Expected Time/Velocity Curve of One Star of Castor C (Binary System), if Einstein was WRONG (Light travels at c=299,792,458 m/sec ± motion of source); here, Castor C is 50 light-years away (about actual). At orbital speeds of 0.0004c, transit times will vary from 50 lightyears/(1-.0004 )lightyears/year = 50.02 years = 18270 days,to 50 lightyears/(1+.0004)lightyears/year = 49.98 years = 18255 days, or about 15 days.

The actual measurements of both of Castor C's binary stars look decidedly like the first graph, and demonstrate very strongly that Einstein was right. At the binaries' relatively small speeds, the differences in calculated velocities between classical and Einsteinian Doppler shifts is insignificant - only a few miles per hour out of hundreds of times the speed of sound.

June 2001 Meeting: Global Warming

by Dave Thomas

At our Wednesday, June 13th, 2001 meeting, we heard Dr. David Gutzler UNM Earth & Planetary Sciences, speaking on "Global Warming: Science and Policy Perspectives." Prof. Gutzler discussed greenhouse warming, the current status of climate change research, and the Kyoto protocol.

Gutzler first described the Greenhouse Effect, wherein sunlight emitted by the 6000^oK-hot sun passes through earth's transparent atmosphere, is absorbed by the ground, and is re-emitted as infrared radiation, which heats up the air. Almost all the energy emitted by the ground is absorbed by the atmosphere in one way or another. Gutzler emphasized that the Greenhouse Effect is not a "villain," if there were no Greenhouse Effect, the earth's temperature would be 33^oC (about 59^oF) cooler than it is today, making the average temperature a chilly 255^oK (-18^oC, or about 0 ^o F). What absorbs the infrared radiation? Nitrogen and oxygen gases (O₂ and N₂) are not good absorbers, so 99% of the atmosphere is not involved. Trace gases, including water vapor (H₂O), carbon dioxide (CO₂), nitrous oxide (N₂O), and methane (CH₄) are the key players. Ozone (O₃) is a player only for incoming sunlight - it absorbs the ultraviolet well, but doesn't react to the infrared radiation emitted by the earth. Gutzler presented data showing that CO₂ levels are increasing, from a pre-industrial level of 280 ppmv to 315 ppmv (1958), and 355 ppmv (1988). There is no plausible explanation for this increase besides people, Gutzler said.

Temperatures have been rising also, but that gets more complicated. In the last century, temperatures increased by 0.6^oC. (See American Geophysical Union's EOS, Vol. 80, No. 39, September 28, 1999, p. 453, "Climate Change and Greenhouse Gases" by Tamara S. Ledley, et. al., online at http://www.agu.org/eos_elec/99148e.html). Gutzler noted that the :Little Ice Age" was a European phenomenon, not a worldwide one. Temperature records, based on oxygen isotopes, overlay beautifully with CO₂ levels, but is temperature responding to CO₂, or is CO₂, responding to temperature? For example, when earth's orbit makes the seas colder (the Milankovitch cycle), they absorb more CO₂. The Greenland ice-core record, going back 100 thousand years, shows that the last ten thousand years have been very stable, the most stable in the last thousand centuries. Gutzler said he is worried because "We shouldn't mess with a good thing."

We do understand some things quite well, like the Greenhouse Effect. We know that CO₂ levels are increasing due to humanity; global temperatures are increasing; and carbon dioxide and temperature are intimately connected in paleoclimate studies. Why is there any debate? One source of uncertainty is climate monitoring: we need to improve our climate observation system, for both present and past changes. Our knowledge of the global CO₂ cycle is incomplete -- what happens to CO₂ emissions? Some of it goes to the oceans, and some to vegetation on the land, but we don't know if it will become saturated in either reservoir. We need better understanding of particulate pollution, which in many cases, such as sulfates, mitigates warming. We don't understand climate feedbacks well enough. For example, if there are a lot of clouds, sunlight will be reflected, cooling the earth, but more infrared will be re-absorbed, heating the earth. If there are more glacial ice sheets, that reflects more sunlight, cooling the earth, creating more ice sheets; as ice sheets retreat, less sunlight is reflected, heating the earth and melting more ice. As water vapor absorbs more heat, the temperature rises, allowing more water vapor to form, which absorbs more heat, and so forth. The situation is so complicated that we need models to study it. Climate forecasts are incredibly difficult, and we've never predicted anything as complicated as this before. In older models, many state-sized parcels of air were used to represent the atmosphere, but clouds are much smaller than states, and could not be accurately analyzed. Newer models have the cell size down to about a degree of latitude (70 miles or so), but are still far larger than typical clouds. We can model some large scale phenomena like the trade winds, but are still having trouble with El Niño.

Prof. Gutzler concluded his talk with remarks on the Kyoto accords. The International Panel on Climate Change, IPCC, didn't issue any conclusion in their 1990 report. By 1995, they concluded there was a discernible effect of humanity on the climate. In 2001, they declared that most of the warming of the last 50 years is human-caused. Critics of the Kyoto accords point to discrepancies between various models as proof that they are all incorrect, but Gutzler noted that it is impossible for different models to agree exactly, and that we need humility in the face of so much uncertainty. The Kyoto protocol was based on the Ozone Depletion treaty of 1992. Its goals for "Annex I" (developed) countries include reductions of greenhouse gas emissions to at least 5% below 1990 levels by 2008-2012, with progress by 2005, and credit for CO₂ sinks (forests, for example). Goals for the 38 Annex I countries include 6% reductions in Japan and Canada, 7% in the USA, and 8% in Europe. There are no goals for non-Annex I countries, and that's one of the sticking points. Fully 55 countries, which include 55% of the emissions, must ratify the treaty before it can take effect; so far, no Annex I countries have ratified the treaty.

NMSR thanks Dave Gutzler for a very interesting talk.

 

May 2001 Meeting: Self-Assembling Materials

by Dave Thomas

At our Wednesday, May 9th, 2001 meeting, we heard Dr. Jeff Brinker, UNM Physics Department and Sandia National Laboratories, speaking on "Self-assembled materials ... From Dishwashing to Nanostructures." Brinker is helping try out a novel collaboration between UNM and Sandia. So far, he said, it's produced some interesting results.

Brinker's goals are not overly ambitious. He simply wants to learn how to control matter on the nanometer scale, devising methods to impart life-like qualities to materials -- such as sensing and responding to their environments. Jeff also wants to learn how to make a material that can repair, replicate, or propel itself. The tricky part is doing this at nano-scales, anywhere from one to 100 nanometers (nm, billionths of a meter). [For comparison to familiar units, a 1-mil (1/1000 inch) garbage bag is a whopping 25,400 nm wide; the wavelength of yellow light is about 500 nm.] Brinker's experiments are on such small scales that he needs a Transmission Electron Microscope just to see what's happening.

At such small scales, photolithography, the method used to produce intricately detailed integrated circuits, is far too bulky and clumsy. With the wavelength of light many times larger than the desired work area, it's like trying to thread a needle with a rope. Brinker was thus led to study methods in which materials assemble themselves.

One remarkable self-organizing material is common dish detergent. Brinker said detergents are "pre-programmed for self-assembly." Detergents are mode of molecules that are hydrophilic (water-soluble) on one end, and hydrophobic (attracted to oils, but repelled by water) on the other end. When detergent is added to water, and energy is added (in the form of splashing or stirring), the detergent molecules naturally line up side-by-side on opposite sides of a thin film of water, creating a new structure (the thin film). Jeff works with silica mixtures; silica is abundant (sand), and silicic acid has many of the properties he needs to exploit.

` Brinker showed a triangular "phase diagram" with water at the lower left, a surfactant ("detergent") on top, and a hydrophobic substance at the lower right corner. He often uses alcohol as the hydrophobic material, and pluronic for the surfactant. Brinker brews up a wicked broth of silica, alcohol and water, and lets it evaporate. As the alcohol evolves, funny-looked studded spheres start to form. As the ratio of ethanol to pluronic and water decreases, the self-organizing reactions change, producing a succession of curious shapes: spheres, then cylinders, then hexagonal pipes, then cubes, and finally lamellar (sheeted) structures. This all happens within a few seconds in the lab.

What good is this nano-tinkering? Well, different-sized surfactants produce different-sized holes, and so this method can be used to make hexagonal arrays of very tiny, very uniform holes - just what is needed to make filters for specific molecules and gases. In addition, material properties such as dielectric constant can be altered; for example, Brinker's group can produce silica with half the dielectric constant of the normal material, making it a better insulator for integrated circuits and similar devices.

Jeff Brinker

Jeff showed many fascinating images of the complex and detailed structures his group and others have produced. Some of the structures looked like the Russian dolls-within-dolls, while others resembled sea-shells, with alternating layers creating strong materials. Brinker's group is now looking at polymerizable surfactants, something that leads to the possibilility of printing out exotic nano-materials using a common inkjet printer.

NMSR thanks Jeff Brinker for a very interesting talk.

 

April 2001 Meeting: Zero-Knowledge Proofs

by John Geohegan

In the April Meeting, Dr. Gustavus Simmons introduced us to the significance and the mathematical basis of zero-knowledge proofs. Professing little knowledge of the mathematics, what follows is my understanding of the subject.

Since the time of Euclid some 2,300 years ago, the method of convincing someone you could prove a mathematical theorem has been to write out the proof and hand it to him. In the last 25 years, however, there has been a major change; it is now possible to convince someone that you have a proof in hand without giving him any knowledge! The new technique is an outgrowth of public-key cryptography which started in the 1970s. In 1986 Manuel Blum published a very readable paper titled "How to Prove a Theorem So No One Else Can Claim It", expanding on a paper the previous year by Goldwasser, Micali, and Rackoff. Blum showed that it was possible to devise a zero-knowledge proof for any provable theorem. Notice there's difference between proving a theorem and persuading someone else that you have the proof.

Writing in the Feb. 17, 1987, New York Times, James Gleick said "Although zero-knowledge proof began as an abstraction, computer scientists quickly realized its applicability to many everyday uses of secrecy. The issue arises whenever someone tears up credit-card carbons, looks over his shoulder while signing onto a computer or worries about the photocopying of a passport left with a hotel concierge."

Zero-knowledge proofs depend upon a series of interactions between the prover and the verifier that are more and more persuasive as the number of interactions increases, and upon the existence of a mathematical procedure that's easy in the forward direction but very difficult in reverse. In modular arithmetic it's easy to square a number but very difficult to extract the square root. For an everyday example, suppose I have a "smart card" that identifies me as knowing the modular square root of a large number, perhaps 200 digits long. In the blink of an eye, a verifying program could determine that I truly know such a square root. The following "humanized" example illustrates the verification process using smaller numbers.

Prover: "I know the square root of 1251, modulo 1517, and I'll prove it without telling you what it is. I also know the square root of 247."

Verifier: "Prove to me you know the square root of 247."

Prover: "The square root of 247 is 42, modulo 1517.(This means that if 42 is squared, giving 1764, and divided by 1517, the remainder is 247. So 42 is called the square root of 247). I also know the square root of 821."

Verifier: "I can multiply 1251 times 821 and get 1,027,071 which leaves a remainder of 62 when divided by 1517. Since you claim to know the two square roots, you should be able to multiply them together and give me a square root of 62. What is it?"

Prover: "217 is a square root of 62. That means that if I square 217 and get 47089, then divide by 1517 I'll get a remainder of 62."

Verifier: "You're right, and I had no way of computing the square root of 62 because I didn't know the square root of either 1251 or 821. Let's do this a few more times and then I'll be very certain that you're giving me perfect square numbers and that you know the square root of 1251."

Explanation: The secret square root of 1251 is 94, and the square root of 821 is 83. When the Verifier asked for the square root of 62, the Prover multiplied 94 times 83, which leaves a remainder of 217 after dividing by 1517. For large numbers, it's easy to find a modular square but practically impossible to find a modular square root. A smart card can prove I know a large square root without giving away any information.

The name of Gus Simmons is sprinkled liberally through the literature of zero-knowledge proofs, validations, public-key cryptography, and factoring of large numbers. After hearing him speak I was inspired to come home and finally gain a rudimentary understanding of both public-keys and zero-knowledge. Our thanks to Bill Fienning and Dusty Cravens for promoting this most interesting meeting, and to Gus Simmons for a stimulating talk

Gus Simmons

 

March 2001 Meeting: The English Language and its Discontents

by Dave Thomas

New Mexicans for Science & Reason (NMSR) heard linguistics Prof. Henry F. Beechhold, retired from the College of New Jersey, Trenton, at our March 14th meeting. Beechhold's topic was "The English Language and its Discontents." Hank began by saying that "Nothing comes close to language in its complexity," and added that computers with all their detailed circuits are not complicated compared to language. Language is our most significant invention, Beechhold said, but we don't yet know how it really works: "How is language reproduced in the brain? How does a thought become a sentence?"

Hank criticized "stupid definitions" like the one for a sentence in grammar: "a subject and a predicate forming a complete thought" - because, he asked, "What is a thought?" He emphasized the connections between language and culture, and noted "The gadgets we invent re-invent us." Beechhold discussed the subtle flavorings of language, and explained how the word "is" can be more than just a factual assertion. For example, "is" can be a value judgment: "He is brilliant." "We look at the world through language-colored glasses," he said. Beechhold went on to discuss the fundamental interplay of presence and absence, and how things are often defined by what they are not: "Bush is no Clinton," for example.

Languages are unstable, just like humans, Beechhold said. Words can be swapped between different languages, and this can happen at different times, with curious "hodgepodge" results. Hank presented the origins of the word "civilization," which began with the word "hive," clearly related to an organized society. The "H" in Hive gradually developed into a "K" sound, and "Hive" morphed into "Kiv," and eventually "Civis," (pronounced "Kivas"); with the later adoption of the soft "C" sound, "kivas" changed into "civis," as in civilization. In a second example, the "D" in "Dent" gradually acquired a "T" sound, while the "T" in "denT" took on a "th" sound, and so the word "DenT" can be seen as directly ancestral to a word with the same meaning: "TooTH."

Beechold discussed the origins and evolution of the English language, which has a common source with Germanic languages. He emphasized the importance of context, and how context is required to make sense of the words: is "fire" a noun? ("Put out the fire.") Or is it a verb? ("Fire the scumbag.") Hank stated that a full grammar is impossible, as is a complete dictionary. Language is too volatile, and the only languages that don't change are extinct ones, such as classical Latin. There are as many as 6000 languages, Beechhold said, and each one is inherently ambiguous.

Hank was the pronunciation editor for a large scientific encyclopedia, and had to choose the "proper" way for scientists to pronounce many science-related words. If you've been saying "kil-ó-me-ter," by the way, it's really "kíl-o-me-ter." Who pronounces "míll-i-me-ter" as "mill-í-me-ter," after all?

Thanks to Hank Beechhold for a fascinating talk.

Hank Beechhold

ADDENDUM: NOVEMBER 8TH, 2002

Beechhold corrects NMSR error...

Hank Beechhold takes issue with part of the summary of his last NMSR talk (March 2001, April 2001 NMSR Reports), and has kindly offered the following as a clarification.

The point I was making was based on Grimm's Law (aka, the First Germanic Consonant Shift), a schema (developed by Jakob Grimm of the Grimm Brothers) that shows how certain sounds in the Germanic sub-family of the Indo-European (IE) family of languages deviated from the other members of the Indo-European family. In this schema, to use but one pair of the affected sounds, what appears in non-Germanic IE languages, such as Latin (and many others) as a "k" sound equates to an "h" sound in the Germanic languages (of which English is a representative example). Thus, where we find in, say, Latin a "k" sound (as in the root "civis-," pronounced "kee-wiss"), we find in, say, English, an "h" sound, as in "hive." This is not arbitrary, for there must be a semantic relationship between the Latin root and the English word. We can see this relationship in the BORROWED word, "civilization" (where the "k" sound, as it happens, has been shifted, via French, to an "s" sound, but this is irrelevant to the point). So our word, "hive," has a semantic relationship with "civilization." This is important for, to repeat, we don't just arbitrarily match sounds up. The match must occur where there is a clear semantic connection. A beehive is, indeed, a "civilization" (as it were) of bees. Another example of Grimm's correspondences is the non-Germanic IE "and the Germanic "T," as illustrated with Latin "dent" (in BORROWED words like "dental," "dentist," etc.) and the English "t" (in English "tooth," exhibiting an obvious semantic relationship to the Latin root). In fact "tooth" shows two of Grimm's correspondences, the d/t pair and the t/th pair. A full explanation of the process that the sound-shift schema represents would take a good deal more discussion than you have space for in the newsletter, and no one but linguistics types would have the patience to follow it! To clarify a question that may arise: diachronic linguists (of which I am one) distinguish between linguistic elements that derive from a parent source - in this case Proto-Indo-European - and those that are simply borrowed at a much later time. English has been particularly free about borrowing, and was pushed hurriedly along this path in the aftermath of the Norman conquest (1066 and all that), although the borrowing actually started much earlier. After the advent of the Normans in England, the Norman brand of French (itself a form of Latin) insinuated itself into English in a big way. This, too, is an overly simple thumbnail view; it would take an entire course (which I gave) to unravel it properly.

- Hank Beechhold

 

January 2001 Meeting: Faster than Light???

by Dave Thomas

New Mexicans for Science & Reason (NMSR) heard Dr. Mohammed Mojahedi, UNM Physics Department, speaking on "Superluminal Velocities and Einstein Causality" at our January 10th meeting.

Before the meeting got started, reporter John Fleck was called up to receive NMSR's first-ever "Honorary Electron" award, in honor of his excellent expositions of neat science stories in the Albuquerque Journal.

Dr. Mojahedi works at the University of New Mexico's Center for High Tech Materials (CHTM) near University and César Chávez. His group has done a fascinating experiment, reported in the October 2000 issue of "Physical Review E," in which pulses have been measured as traveling faster than the speed of light in vacuum, some 300 million meters per second.

Dr. Mojahedi described the background of the work, starting with Maxwell's development of the theory of electromagnetic waves, and Hertz's confirmation of their existence. Einstein's special theory of relativity said that the laws of physics were the same in all inertial reference frames, and that the speed of light in vacuum was constant in all inertial frames; Einstein also showed that matter could not be accelerated to exceed the speed of light. Sommerfeld and Brillouin analyzed several different kinds of "velocity," including phase velocity, group velocity, energy velocity, Sommerfeld signal velocity, and the velocities of Sommerfeld and Brillouin "forerunner" signals. There are many ways to define velocity, and Mojahedi wondered which ones were subject to Einstein's laws.

In Mojahedi's experiment, a beam of microwaves was split into two, and the path lengths for the two beams calibrated. Then, a special array of plastic window panes was inserted into one of the beams. One might expect that the array of windows might slow down the pulse, delaying the arrival of that beam. But, just the opposite happened. Mojahedi's group consistently measured the window-path beam's main pulse as arriving half of a billionth of a second before the pulse from the vacuum-path beam; for the small distances involved on the lab table, this amounted to a speed of 2.38c - over twice the speed of light!

The effect is due to quantum tunneling effects in the window materials, dielectric photonic crystals. Mojahedi exploited a curious property called "Evanescent Mode Propagation" to achieve his surprising results.

But, how surprising were the results? Was Einstein causality violated? Mojahedi said "No." The faster-than-light-speed ("superluminal") propagation was observed only for the main part of the pulse signal. This is the large-amplitude part of the pulse that is easy to measure. It's much harder to measure the very beginning of the signal - the "forerunner" or "precursor" - because those signals have very small amplitudes. Yet, the forerunner signals are the ones that obey the cosmic speed limit of the universe, the speed of light.

Mojahedi used an analogy involving race cars. The forerunner signals correspond to the sharp front edge of the race cars, while the main section of the race cars, containing the driver, correspond to the main pulse of the signals. In both the "normal" and "superluminal" paths, the forerunner signals arrive at the same time - both travel at the speed of light, no faster. (See points labeled A and A' on the diagrams below). However, the main pulse is accelerated in the photonic crystals, with the result that it arrives earlier in the superluminal path (going through the special windows) than through the vacuum path. (See points labeled B And B' on the diagrams below).

The figure below shows signals like the ones Mojahedi's group measured. The Sommerfeld forerunner signals arrive at the same time for both the normal path (A, top) and "superluminal" path (A', bottom). The Brillouin forerunners arrive next, with the superluminal path's signal winning that race by a small amount. The main envelope of the superluminal pulse arrives earlier (B') than the envelope for the normal pulse (B). And so the velocity of the forerunner pulse does not exceed that of light, but the "group velocity" (for the main pulse envelope) does.

Mojahedi described how his work challenges some of the earlier thinking in this field, such as comments by Borne and Wolfe, and Brillouin, that superluminal group velocities had no physical significance or meaning. Does this work suggest that faster-than-light communications might be possible? Unfortunately, no. While the superluminal pulse (B') might arrive before its vacuum counterpart (B), it will never precede the arrival of its precursor (A'). That would be like the driver of the race car reaching a point before the leading edge of the car does. However, the work may hold promise for speeding up detection of pulses in applications such as computing.

Thanks to Dr. Mojahedi for a delightful talk.

 

 NMSR Site Map