Category Archives: STEM Education

Pasteur and Chirality

La chance ne sourit qu’aux ésprits bien préparés, Louis Pasteur

The wine industry is and has always been an important part of the French economy. Because wine-making is dependent on chemical processes in which yeast digests the grape sugars and transforms grape juice into wine, French scientists have learned much about chemistry from wine.

In 1847, Louis Pasteur, at age 25, had just received his doctorate in science and was still working in the lab at the French École Normale Supérieure in Paris, when the wine industry presented him with a puzzle.

Tartaric acid is a natural by-product of wine fermentation and was first isolated in 1769. It coated the walls of wine vats and it was also valuable having uses in medicine and manufacturing. Chemists were interested in its properties that could be explored by examination of its crystals. It was known that some crystals were optically active; that is, that some would bend polarized light to the right or to the left.  A French physicist named Biot had done this with tartaric acid crystals and found that the crystals rotated the polarized light clockwise (to the right).

In 1819 an accident resulted in the synthesis of what was believed to be tartaric acid.

However, when a distinguished German chemist and crystallographer named Eihard Mitscherlich compared the natural tartaric acid with the synthetic version he found them to be identical in all respects, except, inexplicably in optical rotation. The synthetic tartaric acid did not cause polarized light to rotate and was therefore distinguished from the natural tartaric acid (TA) with the name of paratartaric acid (PTA).

For Pasteur simply giving the unknown substance a new name didn’t resolve the puzzle.

Why would the synthetic version of tartaric acid have no effect on polarized light when its apparently identical twin caused the light to rotate to the right?

Pasteur grew crystals of the PTA and, using a magnifying glass looked at them very closely.  Each crystal was certainly a mirror image of each other crystal. In a mirror image, one image can be placed over its mate, matching perfectly.  Pasteur later wrote: “Here now is the crystallographic difference between these two types of crystals. They are all hemihedral (that is, having only half the plane surfaces needed for symmetry); but some are hemihedral to the right, others to the left…” The illustration on the left is Pasteur’s drawing of the two types of crystal while the right image marks the right and left facets that make the mirror images non-superposable.

When he tested the crystals with polarized light, he found that “the direction of [optical] rotation depends on this dissymmetry.” (Gal, 2015, p.10)

The puzzle had been solved.  The TA created during the fermentation of grape juice was composed of only “right-handed” (hemihedral to the right) molecules while the PTA, the synthesized tartaric acid was a 1:1 mixture of right-handed and left-handed molecules. The synthetic tartaric acid was optically inactive because the right-left mixture cancelled each other.

Pasteur’s word was that the crystals were “dissymmetric.” Much later, in 1894, Lord Kelvin would name molecules that would form such crystals “chiral” using the Greek word for hand. A chiral molecule will have two versions that are mirror images of one another (like your two hands) but, also like your hands can’t be superposed on one another.

While everyone knows about Pasteur or at least about pasteurization, his discovery of chirality is less well-known but it is one of his most important.

Over time scientists have learned that many molecules, particularly those based on carbon, which means biomolecules, those that compose living organisms are chiral.

And, it turns out, chirality matters, a lot.

In living organisms, chiral compounds are usually present in one form only: amino acids, carbohydrates and nucleic acids as well as enzymes are right-handed or left-handed but never both.

This explains why the natural tartaric acid produced during the fermentation of wine was the right-hand version only. The yeast that changed the grade juice into wine is what is now called “steriospecific;” which means it produces, either the right-hand or left-hand version of molecules but not both. If, on the other hand, chiral molecules are produced by ordinary chemical mixing and reacting, the output will be a mixture of the right and left versions in a 1:1 ratio, as in the paratartaric acid.

More than half of drugs in current use are chiral. And nearly 90% of those are manufactured using ordinary chemical processes which means that half of the molecules (the right-handed or the left-handed) perhaps doing nothing or, perhaps doing harm.

In 1957 thalidomide was introduced as a treatment for morning sickness. However, women who took the drug were likely to bear children who were severely handicapped.  The developers were unaware that the drug contained both the helpful right-handed molecules that eased the morning sickness but also the left-handed molecules that caused severe birth defects.

Modern pharmaceutical science attempts to ensure that the process produces the proper molecule, that is the one that fits the intended receptor.

One way to do this is to make biomolecules by using living organisms. Insulin is now manufactured by a bacterium that has had a gene inserted into its DNA that causes it to create insulin with the proper chirality.

Why did the very young Pasteur make a discovery that was missed by many other, older and more experienced scientists? The adolescent Pasteur wanted to be an artist. He reproduced some of his quite accomplished pictures using lithography in which an image created on limestone is transferred to paper but backwards. “Isn’t this the explanation of how he saw the handedness on the crystals — because he was sensitized to that as an artist.” Klein, 2017).Chappuis

One of Pasteur’s quotations reflects this: “Chance smiles only on those who are well-prepared.”


Gal, Joseph (2015). Louis Pasteur, Language, and Molecular Chirality — I. Background and Dissymmetry. PubMed, January 2011, DOI: 10.1002/chir.20866


Klein, Joanna (2017). How Pasteur’s Artistic Insight Changed Chemistry. New York Times, June 14, 2017. Retrieved from


Nguyen, Lien Ai, et al. (2006).  Chiral Drugs: An Overview. International Journal of Biomedical Science. 2(2); 85-100. Retrieved from


The images of the paratartaric acid are in the public domain retrieved from



Recent Research: Three Voucher Programs, Indiana, Louisiana, and Ohio

The policy of providing vouchers to pay tuition for public school students to attend private schools aims to give families whose income falls below a certain level or whose children attend schools that are deemed to be “failing” the option of sending their children to a private school.

The principle behind the voucher strategy is the assumption that any given private school is better than any given public school, therefore a child who can attend a private school will receive a better education than in a public school. However, because private schools have historically served children from affluent families, their supposed “better” may be an artifact of their student population.

State voucher legislation has an accountability requirement that private schools accepting state funds must use the state accountability test to measure student progress. This means that researchers are able to compare progress made by voucher students with their peers in public schools using the same criteria, a standards-based accountability examination that covers the same content for both groups.

The fact that students in private schools take the same accountability tests as their peers in public school makes it possible to test the principle results of private school superiority.

Research on voucher programs has yielded mixed results with some students in some settings doing well while other students in other settings show no differences.  So, black students in New York City experienced growth in reading and math but there were no gains for their Hispanic peers in either reading or math. In the District of Columbia voucher program reading scores improved after the third year in the program while there was no improvement in math. There was no evidence of differences in reading scores in Milwaukee. Other educational outcomes like higher rates of graduation were found in New York and DC along with higher rates of college attendance in New York. (Dynarski, 2016)

Indiana, Louisiana, and Ohio each has a voucher program and each of these has been studied over the past year and a half. The question that each of the studies tested was when compared to their academic performance in public school, was their subsequent performance in private school the same, better, or worse.

Indiana’s voucher program began in 2011 and was continued and expanded in 2014. There is now no limit to the numbers of students who can participate. In addition, the means test has been modified to allow families with higher incomes to participate.

In a study conducted by Drs. R. Joseph Waddington and  Mark Berends, respectively from the University of Kentucky and the University of Notre Dame found that students switching from a public school to a public charter experience no differences in achievement. In the case where students switch to a private school using an Indiana voucher, students experienced annual loses of -0.09 SD in mathematics and -0.11 SD in English-Language Arts. Studens who switched to Catholic schools experienced losses of -0.18 SD in mathematics. (Waddington and Berends, 2016, #27765)

The Louisiana Scholarship program was studied by the Education Research Alliance for New Orleans. As with the Indiana study it also found consistently negative consequences for the academic performance of students using vouchers to attend private schools.  A student performing at the 50th percentile in math at a public school who then enrolled in a private school using a voucher saw his/her performance decline to the 34th percentile after one year. If the student was in the third, fourth, or fifth grade, the decline was to the 26th percentile. There were similar declines in reading, to the 46th percentile from the 50th. (Mills et al., 2016)

Finally, research funded by the voucher-friendly Walton Family Foundation and conducted by the Thomas B. Fordham Institute examined the Ohio EdChoice voucher program. The conclusion from the study was that “Students who use vouchers to attend private schools have fared worse academically compared to their closely matched peers attending public schools.” (Dynarski, 2016) & (Figlio and Karbownik, 2016, p. 39)

The three studies of voucher results in Indiana, Louisiana, and Ohio undercuts the assumption that is beneficial to students to move from a public to a private school.

It is a fact that since the decade of the nineties  public schools have been “under heavy pressure to improve test scores” something that private schools have not had to consider.  There is further evidence that public schools actually outperform private schools. 

In a NAEP funded study of NAEP mathematics scores, Lubienski & Lubienski (2006) found that when demographics and location were controlled, public schools “significantly out-scored Catholic schools by over 7 points in 4th grade math, and almost 4 points in 8th grade. math. Of private school types studied…the fastest growing segment of the private school sector, conservative Christian schools, were also the lowest performing, trailing public schools by more than 10 points at grades 4 and 8.” (Lubienski and Lubienski, 2006, p.4)  Note: the public schools in both Ohio and Indiana public schools performed above the national average on the most recent NAEP for fourth grade reading and mathematics.

The mixed results in earlier research on vouchers and the fairly unequivocal results of three studies described above pose interesting questions for both policymakers and parents to consider.


Dynarski, M. (2016). On negative effects of vouchers. Economic Studies at Brookings: Evidence Speaks Reports, 1(48). Retrieved from

Figlio, David (2016) Evaluation of Ohio’s EdChoice Scholarship Program: Selection, Competition, and Performance Effects retrieved from

Lubienski, C., & Lubienski, S. T. (2006). Charter, Private, Public Schools and Academic Achievement: New Evidence from NAEP Mathematics Data. National Center for the Study of Privatization in Education. Retrieved from

Mills, J., N., Egalite, A. J., & Wolf, P. J. (2016). Education Alliance for New Orleans. Retrieved from

Waddington, R. J., & Berends, M. (2016). School Choice in Indianapolis: Effects of Charter, Magnet, Private, and Traditional Public Schools. Education Finance and Policy. doi:doi:10.1162/EDFP_a_00225


school choice, vouchers, private schools, Indiana, Ohio, Louisiana, test scores, parochial schools, types of private schools

The Great Mystery of Biology: The Eukaryote Cell’s Origin

The origin of eukaryotes is one of the hardest and most intriguing problems in the study of the evolution of life, and arguably, in the whole of biology.”(Koonin, 2015)
All living things are composed of either prokaryote or eukaryote cells. The prokaryote cells are simple, basically a blob of protoplasm encased in a cell membrane while the eukaryote cell is larger, possesses a nucleus, (a kind of DNA-packed control room safely enclosed in a membrane), as well as a set of specialized organelles (“little organs”) that are able to perform necessary tasks like storing molecules or protein manufacture. Significantly the eukaryote cell has its own power plant in the form of mitochondria.
For nearly 2 billion years after the appearance of life on Earth, the prokaryote model had Earth to itself. It was and continues to be highly successful at not only surviving but also thriving. Prokaryotes can be found in all of Earth’s habitats from clouds to the depths of the sea, using a repertoire of ways to survive, from the ability to cause disease, use noxious substances like crude oil for food, power themselves with energy from the Sun, and even to swap genes with one another. (Yong, 2014)
The eukaryote cell with its nucleus and mitochondria, doesn’t appear until much later in Earth’s history, about 1.5 billion years ago.
While the prokaryotes “have repeatedly nudged along the path to complexity” and while some groups of prokaryotic cells move in colonies that resemble complex life, “none of them have acquired the full suite of features that define eukaryotes: large size, the nucleus, internal compartments, mitochondria…” (Yong, 2014)
This is why the appearance of the eukaryote (“eukaryogensis”) is “regarded as one of the major evolutionary innovations in the history of our planet” because the eukaryote cell with its mitochondria, its own power plant provides “the host cell with a bonanza of energy, allowing it to evolve in new directions that other prokaryotes could never reach,” and accounts for the reason why all multicellular life is based on the eurkaryotic cell. (Zaremba-Niedzwiedzka et al., 2017 & Yong, 2014)
In an article in Nature published in January 2017, the authors argue that “most recent insights” support a variety of symbiogenesis of eukaryotic evolution. Evidence is that a still mysterious host cell from the domain Archaea merged with “an alphaprotobacterial (mitochondrial) endosymbiont.” (Zaremba-Niedzwiedzka et al., 2017)
That the mitochondria in the eukaryote cell was once a free living bacteria was first proposed by Lynn Margulis in 1967, at the time a graduate student.
Margulis argued that one driver of evolution was symbiosis, with evidence based on the fact that the mitochondria in eukaryotic cells look remarkably like bacteria. Another example for this endosymbiosis are chloroplasts which also look like bacteria. With the coming of new genetic tools, analysis of the chloroplast genome by the University of Illinois’ Carl Woese showed that the chloroplast genes were not at all like the genes in the host cells, but turned out to be the DNA of cyanobacteria. It was also found that the mitochondrial DNA resembles that which is found in the group of bacteria that causes typhus.
New technologies have expanded the tools that are available to track the relationships between organisms, adding new data to the quest to solve the mystery surrounding eukaroygenesis. While the bacteria that contributed the mitochondria to the eukaryote was from the group known as alphaproteobacteria, a group well-known to take up life within the cells of plants and animals as both mutualists and pathogens.(Williams, Sobral, & Dickerman, 2007)
But less is known about the organism from the domain Archaea that was the presumed host in the merger.
In 2015 a team from Sweden’s Uppsala University collected and analysed sediments from an ocean floor field of hydrothermal vents lying between Norway and Greenland called Loki’s Castle. The DNA found in the sample show that these Lokiarchaeota are the “best approximations that we have for that ancestral archaeon that gave rise to us all.” (Yong, 2017)
More searches in places like North Carolina, Yellowstone National Park, and New Zealand, have revealed many more varieties from this group of archaea, which the group has named Asgard (a name from Norse mythology).
The DNA from these organisms have turned up genes that until now that were thought to be unique to eukaryotes. There are genes in the asgard archaea that serve in eukaryotes for building internal skeletons, although the archaea do not have internal skeletons. Other genes are associated with the pinching off of the outer membrane of cells to create little pockets that are used to move molecules around, another eukaryotic capability not found in archaea.
It would be wrong to say that these discoveries have solved the mystery of eukaryogenesis. A lead researcher in this field describes these cells, not as eukaryotes but “primed to become eukaryotes.”(Yong, 2017)
The Agard archaea are perhaps the link that connects the most ancient life to our own.

Koonin, E. V. (2015). Origin of eukaryotes from within archaea, archaeal eukaryome and bursts of gene gain: eukaryogenesis just made easier? Philosophical Transactions of the Royal Society B, 370(1678). Retrieved from
Williams, K. P., Sobral, B. W., & Dickerman, A. W. (2007). A Robust Species Tree for the Alphaproteobacteria. Journal of Bacteriology, 189(13). Retrieved from
Yong, E. (2014). The Unique Merger That Made You (and Ewe, and Yew). Retrieved from–acquisitions/the-unique-merger-that-made-you-and-ewe-and-yew
Yong, E. (2017). A Break in the Search for the Origin of Complex Life. The Atlantic. Retrieved from
Zaremba-Niedzwiedzka, Caceres, E. F., Saw, J. H., Bäckström, D., Juzokaite, L., & Vancaester, E. (2017). Asgard archaea illuminate the origin of eukaryotic cellular complexity. Nature Immunology, 541(7637), 353-358. Retrieved from
See the South Carolina Academic Standards and Performance Indicators for Science 2014: Biology I, Cells as a System, H.B.2.
South Carolina Biology Standards, eukaryotes, prokaryotes, Eukarya, Archaea, Bacteria, domains, Carl Woese, Lynn Margulis

Nature in the Front Yard: Evolution in the City


The voyage on H.M.S. Beagle that led to the theory of evolution took Charles Darwin to many remote places, most famously, the Galápagos Islands, 1000 km off the coast of Ecuador in the Pacific Ocean.

But whether on a Pacific island or in the middle of New York city, the forces of evolution are in operation because science assumes that the universe is a vast single system in which basic laws are consistent no matter where you look. (Quinn et al., 2013)

Actually urban areas are different in one important respect which is that the rapidity of evolutionary forces depends on the “strength of natural selection — the relative benefit that a particular characteristic bestows on its bearer — is strong.” Even a small difference can matter greatly, especially in an urban environment because it is about as extreme and stressful as it is possible to find with its temperatures (warmer than surrounding countryside); its noise (a constant and invasive din that drowns out the usual warning sounds); further the urban landscape is encased in concrete and other substances hostile to the gripping of claws or traction for paws.  Then there are lots of humans, with their tempting trash along with their deadly cats and dogs, their waste that pollutes water, air, and soil.  (Schilthuizen, 2016)

This means that as the world becomes increasingly urbanized, more and more organisms are either being engulfed by urban areas or are gravitating to opportunities found in them.

Biologists therefore are “beginning to realize that the expanding urban sprawl is perhaps not something to be depressed about but something very exciting, as entirely new forms of life are evolving” in them. (Schilthuizen, 2016)

Jason Munshi-South, the director of the Munshi-South “Evolution in the Anthropocene” lab at Fordham University sees New York city as not only one of humanity’s greatest accomplishments but also as the home to native wildlife that are “subject to a grand evolutionary experiment.” (Munshi-South, Ted Ed talk)

Four hundred years ago the territory that makes up modern New York was covered by forest and meadow and was the home to a huge population of white-footed mice.

Four hundred years later the forests and meadows have largely been replaced by city streets, office buildings, multi-storied apartment buildings, and lots and lots of people, with their dangerously fast moving automobiles, noise, food waste, and trash while the white-footed mice are now crowded into the small patches of forest and meadows of the city’s parks. For Munshi-South the mice provide a model of what happens when wild organisms are engulfed by an urban ecosystem.

Advances in genetics have made it possible to identify changes that have occurred in a species because an organism’s genome is a record of its genetic history as well as that of its ancestors.

Genes are short segments of DNA which carry the recipes for creating the amino acids which are the building blocks for the proteins that actually do the cell’s work: its metabolism, its immune response, its reproduction, and so on.

If it happens that a single base pair on a gene changes and the change leads to an advantage for the mouse, for example, more babies, then this change will spread through a population because it will provide the individuals possessing the trait with increased fitness in the competition for survival. (Munshi-South, 2012)

After the examination of several thousand snippets of DNA from the genomes of 191 individual mice taken from 23 sites representing samples of both urban and “wild” environments, and then comparing the results with computer models the investigators were able to trace the history of the population of white-footed mice living in the area around New York.

About 12,000 years ago (coincident with the end of the last North American ice age) when rising sea levels separated Manhattan from the mainland, the genomes of the mice on Manhattan began to diverge from those on the mainland. Then about 400 years ago when Europeans began the settlement that soon became New York, more genetic divergence began to appear as the green space gave way to urban development. As Stephan Harris, a postdoctoral evolutionary biology researcher at Columbia University said, “The exciting thing is that the times of the divergence that we inferred lined up with the arrival of Europeans in New York.” (Netburn, 2016)

In the relatively brief time that New York has been populated by humans, the once genetically similar population of white-footed mice have evolved into genetically distinct populations each inhabiting a different park. The mice in one park are distinctive enough that the home park of a randomly selected New York white-footed mouse can be identified by examining just 18 snippets from its genome.

More significantly, the mice in different parks have developed park-specific traits related to their response to infection, their metabolism, and even their tolerance for environmentally occurring heavy metals like chromium and lead. (Munshi-South, 2012)

You don’t need a berth on the H.M.S. Beagle that will take you around the world to find evolution in action.

There are lots of great opportunities for “citizen science” projects where you can study nature in your home and neighborhood by tracking your local cats or the microscopic mites (Demodox) that are at home in the pores of your skin (yes, yours and mine).

You can find more about these projects at the Your Wild Life website.




Menninger, Holly & Rob Dunn. Your Wild Life: Exploring biodiversity in our daily lives.

Munshi-South, Jason (2017). Evolution in Anthropocene. Retrieved from


Munshi-South, Jason (2012). TED Ed.  Evolution in the Big City, retrieved from


Netburn, D. (2016c). Why the City Mouse and the Country Mouse Have Different Genes. Los Angeles Times. Retrieved from


Schilthuizen, Menno (2016). Evolution is Happening Faster Than We Thought.  New York Times, Sunday Review, July 23, 2016. Retrieved from


Quinn, Helen R., Schweingruber, Heidi, Keller, Thomas, & others, A. A Framework for K-12 Science Education: Practices, Crosscutting Concepts, and Core Ideas. Washington, DC: National Research Council of the National Academies. Retrieved from



evolution, urban ecosystem, fitness, gene, genome, genetics, white-footed mouse, New York, natural selection, citizen science, project-based curriculum



Our Ever-Stranger Universe

For most of human history, we believed that what we saw, heard, and felt was all that made up the real world. This changed around the beginning of the 20th century when modern science began to make uncomfortable discoveries such as that by Wilhelm Conrad Roentgen whose discovery of X-Rays revealed that even more of a reality that was invisible and undetectable by our ordinary senses, or by our “common sense.”
Roentgen won the first Nobel Prize for physics in 1901. Subsequent Nobel Prizes have continued to show how our normal world is really composed of many strange new worlds as revealed by microscopes, telescopes, X-rays, and gravity waves.
What we once imagined as being strange (“goblins, ghosts, and things that go ‘bump’ in the night”) are nothing when compared to the strangeness that science has revealed. As the British evolutionary biologist J.B.S. Haldane noted the universe is not only queer, “but even queerer than we can suppose.”
And now it turns out that “everything on Earth, everything ever observed with all of our instruments, all normal matter,” represents only about 5 percent of reality. The remaining 95 percent is composed of something called Dark Matter and Dark Energy, which are undetectable except by their effects.
The road to this discovery began with a series of investations made in the 1970s by Vera Rubin, a researcher at the Carnegie Institute in Washington, DC.
Rubin’s work focused on the dynamics of stars within galaxies, how the gravity within galaxies affects the stars in the galaxy. She was measuring the speed of the stars in various parts in a spiral galaxy by examining the spectra of light emitted by the stars. A star that is moving away from the observer will show that its spectrum will shift toward the red end of the spectrum while one moving toward the observer will shift to the blue end. The shift will be proportional to the star’s speed. (The Doppler Effect: the change in frequency or wavelength of a wave (or other periodic event) for an observer moving relative to its source.)
According to our understanding of the effect of gravity on the motion of stars, those at the center of a spiral galaxy (where there is more mass) should rotate faster than those farther from the galaxy’s center. (The phenomenon is known as the “galactic rotational curve.”) Strangely Rubin’s measurements showed that stars farther from the center of the galaxy were rotating as fast as those nearer the center.
Rubin and a colleague checked their data by examing the motion of stars in 60 other spriral galaxies and found the same outcomes. The outcomes revealed that there was a “galaxy rotational problem.”
Rubin’s solved it by using the rotational speed of the stars she studied in order to calculate how much mass was needed to account for the gravity needed for the stars to attain their observed rotational speed.
Her calculations revealed that the galaxies must contain about 10 times more mass than could be accounted for by the visible stars, and concluded that 90 percent of the mass in the galaxies she tested was invisible. “What you see in a spiral galaxy is not what you get,” Rubin observed. (AMNH, 2000)
Rubin’s results were treated with skepticism until, when in the 1990s, astronomers began to calculate what they anticipated would be the deceleration of the Universe’s expansion. The surprise was that, the Universe appeared to be accelerating instead. Calculations of the total visible mass in the universe against the gravity that was holding galaxies and solar systems together revealed a “missing matter problem.”
Every mass in the universe attracts every other mass proportionally to the product of their masses and inversely proportional to the square of the distance between them. Calculations of the gravity needed to account for how objects are held in galaxies and galaxy clusters, reveals that the visible universe (“everything on Earth, everything ever observed with all of our instruments, all normal matter”) accounts for only about 5 percent of the mass needed. (You can see the calculations required to support these conclusions here.)
The remaining “roughly 68%” of the universe is dark energy while 27% is dark matter. (NASA, Universe)
So the normal matter, what has been studied deeply is not actually normal. What is normal, the “dark” matter and “dark” energy interacts gravitationally just like ordinary matter does—clumping into galaxies and galaxy clusters. It is “dark” because it doesn’t interact in any way that we can so far detect with light. “It is not made up of atoms and doesn’t carry an electron charge.” (Randall, 2017)
This is science, so investigations continue.
Brian Koberlein, an astronomer at Oberlin College, explains the facts that support the Dark Matter/Dark Energy theory.
Since the 1920s discrepencies have been found that are explained by either that our understanding of gravity is wrong or that there is more mass in the universe than we can see.
But our current gravitational model does seem to work and alternatives that have been proposed have been disproved by observation, leading to the conclusion that the second clause in the previous sentence is true.
Next the proposition that there are examples of mass that only interacts weakly with light is true. Neutrinos have mass and weakly interact with light but there must be additional types of dark matter.
Koblein concludes with the statement that we “know…how much Dark Matter and Dark Energy. there is in the universe, as well as its distribution among the galaxies. “Dark Matter is not just a name we use to hide our ignorance.”

Kobelein, Brian (2017). Dark Matter Works. Retrieved from

NASA Universe. Dark Energy, Dark Matter. Retrieved from

Randall, Lisa (2017). “Why Vera Rubin Deserved a Nobel Prize
NASA (2017). Dark Energy, Dark Matter. Retrieved from

Vera Rubin (2000). Retrieved from

dark matter, dark energy, Vera Rubin, gravity, strange universe, Nobel Prize, astronomy, cosmology

Changing the Relationship Between Knowledge and the Child

Robotics combines engineering, engineering design, and technology in ways that, in the words of Marina Bers of the Tufts DevTech group, “connects the T and the E of STEM” and certainly merits a prominent position in STEM education.
Robotics appears to fit into the STEM sequence as a subject for older students. At the Tufts DevTech research group however, robotics has been introduced successfully to pre-Kindergarten children reasoning that because interventions that begin early are, in the long run, less costly and also have greater impacts than those that begin later, robotics should be begun early
Watch this DevTech produced video clip that documents the robotics work of young children.
The spirited dancing of the children is accompanied by dance movements enacted by two-wheeled robots, which while less enthusiastic are more rhythmic and more disciplined than the children’s.
It is notable that although the robots are better at following the music’s rhythms, the robots’ movements were programmed by the same somewhat syncopated children. The video supports the case that young children are quite capable of engaging in robotics in non-trivial ways.
In their work with young children the DevTech research group uses a computer language called CHERP (Creative Hybrid Environment for Robotic Programming). The CHERP language substitutes a set of interlocking wooden blocks for typed in text. Each block is labeled with a graphic representing a command such as FORWARD, BACKWARD, BEGIN, or END. The program is “written” by assembling the commands by arranging the blocks. “The shape of the interlocking blocks and icons creates a physical syntax that prevents the creation of invalid programs and also eliminates the possibility of typographical errors,” notes Marina Bers. Once the blocks have been arranged to create a program for the robot to follow, a scanner on the robot is used to read the program into the robot’s memory.
The behavior of the robot will mimic the program developed by the child-programmer. Because the program is represented by the arrangement of blocks, children are able to make changes to the program by a rearrangement of the blocks. In addition, they can observe one another’s work and to see how other children have solved a particular problem (“how did you make the robot spin five times?”)
In a number of published studies Bers and her colleagues have collected evidence that
Robotics offers young children and teachers a new and exciting way to tangibly interact with traditional early childhood curricular themes. This study demonstrates that it is possible to teach Pre-Kindergarten children to program a robot with developmentally appropriate tools, and, in the process, children may not only learn about technology and engineering, but also practice foundational math, literacy, and arts concepts. While there are many challenges to overcome when implementing robotics in a busy Pre-Kindergarten classroom, our work provides preliminary evidence that teaching young children about and through computer programming and robotics using developmentally appropriate tools may be a powerful tool for educating children across multiple domains.
What is the reason that in addition to robotics and computer programming the “children may not only learn about technology and engineering, but also practice foundational math, literacy, and arts concepts?”
Seymour Papert who was a developer of the computer language LOGO in the 1970s asserted that a programming language like LOGO (or CHERP) changes the relationship between the child and knowledge.
He argued that most school instruction was based on “transmission” or the passing of “knowledge” from its possessor (the teacher) to the receiver (the student). When computers are used in schools, Papert’s argument continued, they are used to “program the child” in the same way that teachers program the child with the “required” knowledge.
The LOGO computer language was designed to enable the child to communicate with the computer. LOGO included a graphical Turtle that the computer’s user could move around on the screen. RIGHT would cause the Turtle to turn 90° to the right. FORWARD 10 would command the Turtle to move 10 paces ahead and so forth.
In the LOGO environment, the traditional relationship between the child and the knowledge was changed.
[t]he child, even at preschool ages, is in control: The child programs the computer. And in teaching the computer how to think, children embark on an exploration about how they themselves think. The experience can be heady: Thinking about thinking turns the child into an epistemologist, an experience not even shared by most adults. (Papert)
In addition, in the usual “teacher as source of knowledge,” model the child is placed in the “got it right/wrong” mode, and worse may not know either what was wrong or how to fix the error.
As Papert notes, when you learn to program, you seldom get it right the first time. “Learning to be a master programmer is learning to become highly skilled at isolating and correcting “bugs,”….
This is also the case with products of the intellect; they are usually neither “right” or “wrong” but are “buggy” works in progress.
If Papert is correct, changing the relationship between the child and knowing is fundamental to learning. Robotics with young children is perhaps a place to begin the change.
Epistemologist: one who studies epistemology: the theory of knowledge, especially with regard to its methods, validity, and scope. Epistemology is the investigation of what distinguishes justified belief from opinion.
Marina Umaschi Bers, Safoura Seddighin, and Amanda Sullivan
Ready for Robotics: Bringing Together the T and E of STEM in Early Childhood Teacher Education Jl. of Technology and Teacher Education (2013) 21(3), 355-377

Sullivan, A., Kazakoff, E. R., & Bers, M. U. (2013). The Wheels on the Bot go Round and Round: Robotics Curriculum in Pre-Kindergarten. Journal of Information Technology Education: Innovations in Practice, 12, 203-219. Retrieved from

Seymour Papert (1980). Mindstorms, Basic Books.

Inquiry: Earning the Right to Believe

Crazy belief or not?
“Ground up unicorn horn will detect the presence of poison.”
In early modern Europe, belief in unicorns and the virtue of their horns was widely accepted. As would be expected, people acted on their beliefs. Thus, a supposed unicorn horn was of course valuable because of its ability to detect poison. So one that belonged to the king of France was priced at £20,000 pounds in 1553. Mary Stuart (1542-87), Queen of Scotland bought a piece of unicorn’s horn and used it regularly to test for poison. (Jackson, 2004)
Of course, it is now well-known that what were believed to be unicorn horns are in fact the tusks of narwhals and that they have no special poison detecting properties. (Maynard, 2014)
We know this because investigators have inquired into the belief; that is, searched systematically for evidence that would give us the right to believe or not in the existence of unicorns.
While there are a variety of different ways that scientists conduct their investigations, at the core of all science is inquiry with its assumption that beliefs about the natural world must be earned by patient investigation. To the scientific mind it is wrong to “believe on insufficient evidence or to nourish belief by suppressing doubts and avoiding investigation.”(Clifford, 1876, p. 292)
The practical value of inquiry is that it provides “strategies with which to examine evidence systematically, interpret, and control our surroundings. Knowledge of science can enable us to think critically and frame productive questions. Without evidence that supports or refutes an idea we are wholly dependent on others as “experts.” With evidence, we are empowered to become participants rather than merely observers.” (Michaels and others, 2007, p. 2)
A vivid illustration of the importance of inquiry can be found in the case of Dr. Andrew Wakefield, a British physician and researcher.
Along with twelve colleagues, Wakefield published a research paper in the British medical journal Lancet in 1998 that “reported on 12 developmentally challenged children” who were diagnosed with “regressive”“autism as well as with “non-specific colitis.” The paper identified a “new syndrome” that linked brain (autism) and bowel disease” and which was caused by vaccination with the MMR vaccine. (Deer, 2011)
The MMR vaccine has been used successfully since 1971 to immunize infants against measles, mumps, and rubella, so naturally the news that MMR vaccine was connected to autism spread rapidly. The consequence of the news was a world-wide scare about the MMR vaccine as well as a reduction in the number of children who were immunized against measles, mumps, and rubella. In Britain the vaccination rate fell from 92% to 78.9%, for example.
Wakefield’s article also caused the development of a movement against all childhood vaccinations including, for example, the DTaP that protects children from diphtheria, tetanus, and pertussis, or whooping cough.
Despite its publication in the Lancet, the experiment on which the conclusions were based seemed flawed. It was a study based on a sample of only 12 children; there was no control group; the data wasn’t analyzed as a whole but selectively; its conclusions were highly speculative (that MMR was related to autism) given the long history of the successful use of the MMR vaccine.
A more detailed inquiry by a journalist named Brian Deer by soon found significant problems in the research.
For example, some of the children’s problems were detected months before the child had received the MMR vaccine.
Even more revealing was Deer’s finding that Dr. Wakefield had been employed a lawyer and paid £400,000 by a lawyer working with a group of parents who were suing the pharmaceutical company that produced the MMR vaccine, and that his research was to create evidence to be used in the law suit.
Even the selection of the subjects for the study was facilitated by the lawyer for whom Wakefield worked. The lawyer solicited subjects for the study by specifying particular symptoms which meant that “the evidence that launched the vaccine scare — was bound to be found by the …clinicians because this was how the children were selected.” (Deer), 2011)
The sensational nature of the Wakefield conclusions spurred a flurry of investigations, none of which was able to confirm the Wakefield findings.
As the cascade of problems appeared, ten of the twelve co-authors of the article retracted their support for the MMR-autism connection because “no causal link was established between MMR vaccine and autism as the data were insufficient.” (Rao, and others 2011)
Ultimately, the British General Medical Council (GMC) investigated Dr. Wakefield’s possible misconduct. In January of 2010, a tribunal of the GMC found three dozen charges against Wakefield proved, including dishonesty and the abuse of developmentally challenged children. The tribunal found that Wakefield “had failed in his duties as a responsible consultant, acted both against the interests of his patients, and “dishonestly and irresponsibly”“in his published research.
The editor of the Lancet fully retracted the article and stated that the paper was utterly false and that the journal had been deceived. (See the notes in resources for the sources)
Despite the fact that inquiry from a variety of sources revealed that both Wakefield and his research to be fraudulent and was retracted from the medical literature in 2010, still in 2016 self-declared experts including celebrities and even some politicians continue to disseminate the fraudulent claim that vaccinations are the cause of autism, with the consequence that parents are led to withhold vaccination and thus protection against serious disease from their children.
There were outbreaks of measles attributed to lack of immunization in the UK in 2008 and 2009 as well as in the U.S. as well as outbreaks of pertussis (whooping cough) with 48,000 cases with fatal outcomes for 20 children. (CDC,
These facts support Clifford’s warning that failure to work for the right to believe by rigorous inquiry has the result that we “all suffer severely from the maintenance and support of false beliefs and the fatally wrong actions which they lead to… . There is a danger to society that “is not merely that it should believe wrong things, though that is great enough; but that it should become credulous, and lose the habit of testing things and inquiring into them….” (Clifford, 1876, p. 294)
Clifford, W.K. (1876). The Ethics of Belief, Contemporary Review (29) 1876.

Deer, Brian (2011). How the case against the MMR virus was fixed. BMJ 2011; 342 doi: (Published 06 January 2011)

Jackson, William (2004). The use of unicorn horn in medicine. The Phamaceutical Journal, 18 December 2004.

Maynard, James (2014) Narwhal tusk – Scientists finally solve its real purpose. TechTimes retrieved

Michaels, and others (2007). Ready, Set, Science! (National Research Council, Washington, DC)

Rao, Saythyanarayana and Chittaranjan Andrade (2011). The MMR vaccine and autism: Sensation, refutation, retraction, and fraud. Indian Journal of Psychiatry 2011 Apr-Jun; 53(2): 96-96. doi: 10.4103/0019-5545.82529

Notes on the Wakefield Case:
“MMR-row doctor failed in his duties”. Yorkshire Evening Post. 28 January 2010. Archived from the original on 30 January 2010. Retrieved 28 January 2010.

Triggle, Nick (28 January 2010). “MMR scare doctor ‘acted unethically’, panel finds”. BBC News. Archived from the original on 28 January 2010. Retrieved 28 January 2010.

Boseley, Sarah (28 January 2010). “Andrew Wakefield found ‘irresponsible’ by GMC over MMR vaccine scare”. The Guardian. London. Archived from the original on 14 February 2011. Retrieved 9 January 2011.

Inquiry, W.K. Clifford, The Ethics of Belief, the right to believe, Andrew Wakefield, The Lancet, measles, mumps, rubella, MMR vaccine

“I really hope it works:” Digital Technology for Instruction


There are many classrooms like English teacher Amy Furman’s featured in a 2011 article Classroom of the Future: Stagnant Scores.

Amy’s thirty-one students are studying Shakespeare’s As You Like It, taking advantage of 21st century digital technology.

Amy is not “giving the students notes” but is circulating among her students observing, offering comments and suggestions as her laptop-equipped students engage themselves with the play in very nontraditional ways.

In the place of an essay on the play’s plot, the students are blogging, or creating Facebook pages for the characters, while others are writing about why the love-smitten Silvius would like a particular rap by Kanye West.

Amy expressed her pleasure with what is going on in her “very dynamic classroom” adding “I really hope it works.”(Richtel, 2011)

This technology-rich classroom is one outcome of a 2005 referendum in which the voters passed a bond referendum that gave the Kyrene School District in Arizona $45 million to “transform the very nature of the classroom, turning the teacher into a guide for students who will learn at their own pace on Internet-connected devices.”

The high cost of the technology needed for the transformation makes the question whether it works a matter of concern.

In 2011, as now, the evidence that such investment in digital technology has been at best ambiguous. Overall, the data that supports the use of technology is “pretty weak” according to Tom Vander Ark, former executive director for education and an investor in educational technology companies.(Richtel, 2011)

In the eleven years after it passed its technology referendum and five years since Amy Furman expressed both the pleasure of teaching in a technology-rich classroom as well as her “hope” that it works, Kyrene School District remains a technology-rich school system. The students in its nineteen elementary and middle schools perform above average, earning an “A” ranking in the Arizona school accountability system.

Its 2016 Website cites the district’s “technology enhanced curriculum” and the fact that

Throughout the entire district, every classroom is enhanced with a variety of technology tools: wireless laptop computers; many with multi-touch display, a projector, a document camera, and iPads, so that students have hands-on access to technology as part of their everyday instruction and learning. Elementary classrooms also have interactive whiteboards. Students use industry-standard word processor and spread sheet programs, specialized graphics and education software, and web-based applications and information sources. Teachers participate in regular staff development and mentoring programs to help them to better use these incredible tools. (Kyrene School District)

Is Kyrene’s success the result of its rich technology or because in it also has both technology along with a well-developed system of instructional support for its teachers: academic coaches and educational technology specials for all subjects?

In education there are no “silver bullets” whether educational technology, textbooks or curriculum.   “One-to-one laptop programs may simply amplify what’s already occurring—for better or worse—in classrooms, schools, and districts. (Goodman, 2011)

If Kyrene is a positive example of the implementation of educational technology, what happened with the Los Angeles Unified School District’s Instructional Technology Initiative (ITI) is a negative one.

The debacle began in 2013 with a district investment of $1.3 billion that was to put an Apple iPad loaded with instructional software from educational giant Pearson in the hands of every child in every school. But by 2015 the district wanted out of the deal claiming that the software didn’t work and that the iPads had fatal security holes.

An observer noted that if one of the largest school districts in the nation, one of the largest educational publisher and the largest technology company couldn’t successfully integrate instructional technology into classrooms, who could? (Lapowski, 2015)

The answer lies up the coast from Los Angeles,  where the Milpitas Unified School District also has made a significant investment in personal technology and has successfully used blended learning to create personalized instruction for its students.

The contrast between the two school districts in how their instructional technology programs came about is instructive.

In Los Angeles, the Instructional Technology Initiative began at the top as did the Milpitas project. However, in Milpitas, Cary Matsuoka, the superintendent began by asking his principals the question: “If you could design the school of the future, what would it look like?”

His goal was to “give principals and teachers the autonomy to determine what would work best for their schools.” Mandating from the top, he reflected, and you “get compliance, where people go through the motions.”

The answers also got him and his district to the understanding that one-to-one wasn’t needed because the principals proposed a “rotation model” in which students would  use the devices in shifts.

The district chose Chromebooks; they are less expensive than iPads because they are cloud based, central management and updating are less of a hassle.

As a departing Board of Education recalled about his eight years on the Board”We went through both academic and sport renewal and modernization, implemented blended learning and common core, build a high-tech infrastructure and new athletic facilities.… For the past eight years, we saw student achievement improved significantly, we are also financially solid.” (Mohammed, 2016)

The contrasting examples provided by Kyrene and Milpitas versus the LAUSD debacle support the contention that educational technology if it is implemented based on a shared vision that include the identification of the actual problem to be solved, if the school and district leadership supports all aspects of the implementation. Implementation requires the development of a technology infrastructure and a culture of professional learning that includes the community, parents and guardians, all school personnel, and the development of a coaching/mentoring model. This last is important because the technology will be a catalyst for changing the connections between learning and instruction.


Greaves, T., Hayes, J., Wilson, L., Gielniak, M., & Peterson, R. Project Red: Revolutionizing Education: Nine Keys to Student Achievement and Cost Effectivenss. Retrieved from

Goodman, B. (2011). Research Says…/One-to-One Laptop Programs Are No Silver Bullet. EdLeadership, 68), 78-79. Retrieved from

Lapowski, I. (2015). What Schools Must Learn From LA’s IPad Debacle. Wired. Retrieved from

Mohammed, Aliyah (2016). Milpitas: School boar names permanent MUSD superintendent. The Mercury News, November 17, 2016. Retrieved from

Richtel, M. (2011c). In Classroom of Future, Stagnant Scores. New York Times. Retrieved from

ESSA, Measuring the Benefits of School Improvement: And How To Do It

Even by the crudest measures, education benefits the individual in terms of earnings and the economy as a whole in more productive workers. The longer an educational system holds on to students, the better for both the individual and economy. The years of education is a measure is called “educational attainment.”

Dissatisfaction with the number of years of schooling as a measure of economic impact led Eric A. Hanushek and two international colleagues to develop a measure that better captures what students have actually learned during their years in school. As Hanushek, et. al. describe educational attainment: “…it hardly matters how long one sits at a school desk if one learns little while occupying the seat.” (Hanushek, Ruhose, & Woessmann, 2016)

The model developed by Hanushek, et. al. uses a measure which they call “knowledge capital” which is a state’s NAEP mathematics scores over time. This measure,  added to traditional measures provides a way to document the long-term impact of student-achievement levels on economic growth, as well as the value of the monetary return for school improvement efforts, state by state[1].

By measuring the growth of each of the fifty U.S. states for the period 1970-2010, the authors show that a state’s knowledge capital is related to the state growth in per-capita GDP.

States like Alabama, Mississippi, Nevada, and Utah suffered from both low math achievement and low economic growth, while states like North Dakota, South Dakota, Minnesota, Massachusetts, and Virginia had both high levels of math achievement along with higher levels of economic growth.

While there are exceptions to the general findings, the authors conclude that “achievement levels that are 1 standard deviation higher — for example having the average worker in a state achieve at the 69th  percentile rather than the 31st   percentile of the overall distribution of cognitive skills — yield an average annual growth that is 1.4 percentage points higher.” (Hanushek, Ruhose, & Woessmann, 2016)

The article includes a an interactive map that can be used to project future gains in GDP growth under four different reform scenarios.

For example, first scenario describes what would happen if all the states were able to take actions that would increase the knowledge capital to the level of Minnesota (the best in the U.S.). Under that scenario “the overall gains would equal, in 2015 dollars, $76 trillion, or more than four times the current GDP of the United States.”

South Carolina ranks 40th  in terms of growth 1970-2010. Its per-capita DGP is $31,819 and has grown 1.99% over the period.  Under the “all states to the U.S. best” scenario, the value of South Carolina reform efforts would be $992 billion which equals 485% of the state’s current per-capita GDP and would increase the state’s GDP by 41% by 2095.

Hanushek and his colleagues are careful to point out that school reform is a long-term project. They assume that it takes a decade of effort before a reform is fully implemented, with student skills steadily improving over that time.

The message from Hanushek, et. al, is that the recently passed Every Student Succeeds Act (ESSA) gives state and local educators a great deal of flexibility to take decisive action that will improve their state’s knowledge capital.  Given the potential of large gains for taking the right actions, the question becomes what kinds of action would help the state build its knowledge capital?

Massachusetts underwent a serious reform effort that began in the late 1980s. Its example suggests the necessary conditions for sustained and successful reform.

The success of reform in Massachusetts is supported by the fact that if it were an independent nation it would rank among the top ten nations in student learning. Its eighth graders rank number two in science and sixth in mathematics. Low-income children of color do much better than their peers in other U.S. states.

It wasn’t always that way.

In a 1991 report authored by the Massachusetts Business Alliance for Education it was reported that the state faced a crisis because “the public education system is failing to provide its students with the knowledge and skills necessary for them to be productive, informed citizens in coming decades…The inability of many public school students/graduates to qualify for entry-level jobs or to compete successfully with their counterparts from other industrialized countries is a clear signal that the education system needs to undergo dramatic improvements soon.”(MBAE, 1991, pp.  ES-1)

Noting that Massachusetts over the past two decades has been consistently near the top of any list of states with the most successful school reforms (it ranks 2nd  in the Hanushek, et. al. analysis), looked at the decisions Massachusetts made beginning more than 20 years ago and which resulted in sustained improvement in the state’s knowledge capital.

In the Achieve analysis, there are six “key strategies” identified. It seems to me that two of these stand out because they are the most difficult to do but seem to the ones that set the Massachusetts reform apart from those in other states.

What stands out in Massachusetts was what was termed the “grand bargain” are two factors: equitable funding and the political will to stick to the plan.

First, a change in how the schools were funded began in 1993 with the promise that within seven years, all of the town and city school departments would have the resources to carry out the goal of student mastery of the state standards. “In our poorest communities in particular, [state] aid is the lifeline that brings a high quality education within reach of children and frequently supports more than 80 percent of the total expenditures of in the neediest districts.”(Chester, 2014, p.  6)

The second remarkable aspect has been the consistent support from state’s leadership,  governors, business leaders, and legislature. The support helped maintain the reform even “during the highest levels of political opposition to the reforms. Governor Jane Swift never blinked on the MCAS high school graduation requirement. Governor Romney also kept the momentum going by sustaining the foundation budget for the K-12 public education.”(, 2009, p.  9)

Note: Schools in New England states are generally departments of the town or city they serve. Instead of a school district, the schools are a department of the town. So it is the school department rather than the school district.

Resources: (2009). Taking Root: Massachusetts Lessons for Sustaining the College and Career-Ready Agenda. Achieve: American Diploma Project Network. Retrieved from

Chester, M. D. (2014). Building on 20 Years of Massachusetts Education Reform. Massachusetts Department of Elementary and Secondary Education.

Hanushek, E. A., Ruhose, J., & Woessmann, L. (2016). It Pays to Improve School Quality. Education Next, 16(3). Retrieved from

MBAE. (1991). Every Child A Winner. Retrieved from


Every Student Succeeds Act, education, economy, knowledge capital, school reform, Massachusetts

[1] The analysis used data from the U.S. census to make adjustments for the migration of workers in and out of each state. While workers move from state to state, 87% of students receive their K-12 education in their birth state.