Monthly Archives: April 2014

Engineering meets Science meets Origami

Malaria affects 1 billion people a year and is particularly devastating for children under 5 who are exposed to it. The way to diagnose is to image a drop of the patient’s blood and magnify it so that it is possible to see if the patient actually has malaria and if so to match the medication to the actual type of malaria the patient has. Unfortunately, the instruments needed to do this imagining are expensive and because of the scale of the problem (1,000,000,000 people!), the instruments would need to be practically free.

Enter Dr. Manu Prakash, an assistant professor of biophysics at Stanford. He and his team are working to develop scientific instruments that can be used by scientists in poor countries.

What about a microscope that could be widely available in those parts of the world where malaria is prevalent, durable, needs no external power source, and is inexpensive?

In addition to using it to help do the nearly 1 billion screenings for malaria, what if you could use this microscope to improve science education?

First, the powerful microscope that is also very inexpensive:

I was expecting it to look like microscopes I used, a tube and a stage for the slide. This looks nothing like that. Instead it is made of heavy paper, folded in such a way that it can be assembled in 20 minutes. It includes an light emitting diode (led) with battery so that it illuminates the specimen and can even project the image onto a large surface such as a wall. While it doesn’t use a ground glass lens, it is capable of a resolution that approaches 700 nanometers! The microscope uses ball lenses which are used to connect fiber optic light sources. 

You can see the complete plans for the microscope here.

When the Foldscope was shown in March of this year,  Dr. Prahash and his team also asserted that an inexpensive ($.55) microscope would not only make the imagining and diagnosis of diseases such as tuberculosis, malaria, African sleeping sickness, leishmaniasis and giardiasis but that it could also add something new to science education.

What if every child had access to a high quality, durable, and inexpensive microscope? 

To answer this question, 10,000 Foldscopes were offered to individuals who will  We intend to enlist 10,000 individuals 

who would be willing to beta-test Foldscope over the summer and develop single page science experiments, protocols, queries, questions, applications based on using Foldscope in a specific community. We aim to collectively write a crowd-sourced biology microscopy manual with examples collected from scientists, teachers, tinkerers, thinkers, hackers, kids and alike. (10,000 Microscope Project)

While the offer is now closed, if you are interested in the project, you can contact Dr. Prakash’s team at info@foldscope.com.

What is nice about the project is that you don’t need a Foldscope to participate. One can take the challenge to develop single page science experiments, protocols, queries, questions…and so forth that employ microscopy as a tool.

 

 

Sources

Science Tools Anyone Can Afford Article from the NYTimes, April 21, 2014

Foldscope: Origami-based Paper Microscope Paper about the creation and specifications for the Foldscope.

Foldscope: Microscopy Anyone Can Afford The 10,000 Microscope Project Description

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Modeling: The March of Kinesin

 

Each week, the journalist Carl Zimmer writes a science-focus column called “Matter” that appears on Thursday in the New York Times. Last week he asked, “if you can shrink down to the size of a molecule and flying to a cell, what would you see?”

You can see the answer in the 3 minute video, “The Inner  Life of a Cell.”

The material in the video is based on new understandings about cells and protein molecules. These understandings were translated into mathematical algorithms that were processed by large arrays of computers that created the animations that make up the video.

The video shows an immune cell moving along a blood vessel seeking for signs of inflammation (a possible indicator of infection).

Now we are taken into the cell itself and see the response to the information. Genes are switched on that create new proteins. These proteins are collected into a vesicle and hauled along the microtubule to the periphery of the cell by kinesin (a motor protein found in all eukaryotic cells) (“kinesin,” Wikipedia). 

While the kinesin looks so much like an human trudging along a pathway, it is a protein, and a “motor” protein at that.

Of course, it isn’t actually a kinesin either; it is a representation of a kinesin. 

It’s a model of a kinesin. The video shows us a model that explains an aspect of the immune system. 

Science often involves the construction and use of a wide variety of models and simulations to help develop explanations about natural phenomena. Models make it possible to go beyond observables and imagine a world not yet seen. Models enable predictions of the form “if . . . then . . . therefore” to be made in order to test hypothetical explanations. (Framework, p. 50)

The image in the video is an attempt to visualize how the “is a mechanochemical protein capable of utilizing chemical energy from ATP hydrolysis to generate mechanical force “if….”

The video is captivating but what might be more instructive would be to watch the development of the model for that explains how the ”mechanochemical protein” transports materials inside the cell. 

You can see how the model building took place.  On the Duke University’ Cell Biology  Kinesin-1 site you can read about experiments that have been done to work out how the kinesin molecule functions as a motor.  You can see a picture of an experiment involving kinesin molecule pulling microtubule that is attached to a glass rod.  In the experiment it was calculated that the kinesin can exert a maximum force of 5 pN (piconewtons).

We get so accustomed to realistic graphical representations of reality, that it’s easy to miss the real wonder that emerges when we attempt to model the natural world. The real wonder happens when we test our model by constructing an investigation so that we can see how well the model explains the data.

 

Some Lessons for Schools from the History of Science and Engineering

 

The history of the discoveries made by people using science and engineering  has some application to how we think about teaching science and engineering in K-12 schools.

In 1820 (April 21 to be precise), the Danish physicist, Hans Christian Ørsted was setting up his equipment by connecting some wires to a battery when he noticed that as soon as the wires and battery were connected, a magnetic compass that happened to lying near one of the wires, moved away from magnetic north. He repeated the process of connecting and disconnecting the wires while watching the compass. Every connection and disconnection created the same effect on the magnetic compass. 

After he had published his notes about the magnet, battery, and wire phenomenon, there began a flurry of activity all over Europe and North America on the part of curious and inventive minds who began to play with and explore this most interesting connection between electricity and magnetism (both  well-known but both also mysterious). 

In 1831, in the far away United States, Joseph Henry used the finding to rig a battery through a wire to a bell to cause a click in a distant part of the school in which he taught

. In Germany in 1833 the mathematician Christian Friedrich Gauss strung wires around his university and developed a code that could be used to send messages from building to building. Charles Wheatstone and William Cooke in London had stretched a wire from one train station to another and used it to signal the imminent arrivals and departures of trains (replacing piercing whistles and annoying drums used previously). By 1832, Joseph Henry had worked out a whole system for sending coded signals over wires for extended distances. He had much of the campus of the College of New Jersey (soon to be known as Princeton University) wired with the system with the help of his students.

Using the work done by Joseph Henry and others, Samuel Morse “invented” (“borrowed”, “stole”?) the electric telegraph and patented it in 1844.

In the space of 24 years the discovery of the connection between electricity and magnetism led to a world changing technology.

Financial news could now be sent instantly between cities, and — along with enhanced opportunities for insider trading — a new style of Corporation arose. Offices in far distant cities could be easily linked. The telegraphs strung beside the rail lines could synchronize departures and arrivals across entire countries.” (Electric Universe, 2005)

The pattern of the telegraph has been repeated over and over again. Investigators into the electrical properties of materials, leads to the observations such as the photovoltaic effect (observed in 1838) leads to many investigations and experiments that lead in many different directions including to semiconductors and the transistor (1948) and the modern computer connected by the World Wide Web.

Is there anything suggestive about the STEM story for schools?

I would suggest three interconnected principles at work in the history that have application to schools and schooling about STEM.

STEM investigations follow these principles and I suggest that when teachers are designing curriculum and instruction, these principles should be honored:

  1. A deep commitment to observation and willingness to be thoughtful to what is seen. How many other experimenters had seen the same phenomenon as Østed but had not thought to ask a question about it?
  2. A willingness to play; that is, mess around with what has been seen. Joseph Henry first applied the idea to electromagnets before he played with telegraphy. Ultimately, he built an electromagnet that would lift 1,500 pounds! The experimentation/playing taught him and his students lots about electricity; for example, that wires wrapped in silk (insulation), would improve the strength of the magnets.
  3. A commitment to the imagination. The first “telegraphs” would only send their signals a few yards. But imagination said, “if you can extend the distance, you can increase the range of communication.”  Imagination led to questions which led to the development of the electric relay that would permit coast to coast communication by the telegraph.

 

 

Reference:

David Bodanis (2005). Electric Universe: The Shocking True Story of Electricity. Crown Publishers, New York.

 

Prize the Doubt: Science and Engineering Practices

Leaves on STEM

Prize the Doubt: Science and Engineering Practices

“It ain’t necessarily so.” Heyward & Gershwin

“There is no learning without having to pose a question. 

And a question requires doubt.” Richard P. Feynman

 

 

Doubt? In schools? Schools are not generally places where doubt or skepticism are much discussed or even encouraged. “Do you doubt my word?” “Are you sure? I hope you’re certain about that answer!”

While doubt and uncertainty may be strangers to the classroom, they are central to understanding science.

As Richard Feynman puts it, 

A scientist is never certain. We know all our statements are approximate statements with different degrees of certainty, that when a statement is made, the question is not whether it is true or false but rather how likely it is to be true or false.… Now we have found that this is of paramount importance in order to progress. We absolutely must…

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Prize the Doubt!

“It ain’t necessarily so.” Heyward & Gershwin

“There is no learning without having to pose a question. And a question requires doubt.” Richard P. Feynman

Doubt? In schools? Schools are not generally places where doubt or skepticism are much discussed or even encouraged. “Do you doubt my word?” “Are you sure? I hope you’re certain about that answer!”

While doubt and uncertainty may be strangers to the classroom, they are central to understanding science.

As Richard Feynman puts it,

A scientist is never certain. We know all our statements are approximate statements with different degrees of certainty, that when a statement is made, the question is not whether it is true or false but rather how likely it is to be true or false.… Now we have found that this is of paramount importance in order to progress. We absolutely must leave room for doubt or there is no progress and there is no learning. (Feynman, pp. 111-112)

But there is a problem because, our brains work very hard to get to certainty and to rid themselves of doubt.  As psychologist Michael Shermer puts it,

The brain is a belief engine. From sensory data flowing in to the senses the brain naturally begins to look for and finds patterns, and then infuses those patterns with meaning. …We can’t help it. Our brains evolved to connect the dots in our world into meaningful patterns and to explain why things happen. These meaningful patterns become beliefs, and these beliefs shape our understanding of reality. Shermer, p. 11)

Once the belief is in place, we find the reasons for holding on to it, and we are generally very good at finding opinions that match our own whether or not those opinions are supported by the data.

In stark contrast,  the scientist begins with doubt and works very hard to maintain skepticism, even about the findings of his or her own investigations.

How do we as teachers manage the paradox between our role as an “authority” and as a teacher who wants to develop in our students the skills of constructing explanations by beginning with questions; that is, by doubting what they have been told, heard, and perhaps even read?

The science and engineering practices play a powerful role in the resolution of the paradox because they provide a portrait of how scientists actually work. How does one approach a natural phenomenon from the perspective of science?

One way to look at the practices then, is as a set of mental disciplines that scientists have developed over time in order to maintain their uncertainty about explanations, including their own.

Just as you have acquired the discipline of brushing after every meal, one develops the discipline of approaching explanations about the natural world with doubt that leads to questions.

Similarly, there is a mental discipline that drives one to attempting to explain a phenomenon by constructing a model, constructing an investigation to test the model by gathering data, finding the patterns in the data, constructing an explanation, arguing for the explanation from evidence and finding, evaluating, and sharing information.

These should be the habits we develop as teachers so that we become models for our students.

 

 

 

 

 

 

 

 

 

 

 

“The Role of Scientific Culture in Modern Society,” pages 111-112, in The Pleasure of Finding Things out: The Best Short Works of Richard P. Feynman. Cambridge, Massachusetts, 1999.

 

Michael Shermer. The Believing Brain: From Ghosts and God to Politics and Conspiracies––How We Construct Beliefs and Reinforce Them as Truths. New York. 2011.