Rethinking Introductory Physics for Life Science Students: A model

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Rethinking Introductory Physics for Life Science Students:

A model for deep curriculum reform

+Outline

  The Challenge   The biologists turn up the pressure

  An Approach to a solution   Opening lines of communication

  Some surprising results   Modifying the IPLS class

  Implications   What if we ... ?

6/7/15 APS Dept. Chairs Conf.

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+THE CHALLENGE

The biologists turn up the pressure

6/7/15 APS Dept. Chairs Conf. 3

+Biologists are clamoring for an upgrade   Leading research biologists

and medical professionals have increasingly been calling for a major reform of undergraduate instruction.


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2003 2009

2011

2013

+This is an interesting challenge. Can we do it?

  These reports have specific requests. They want courses that   Stress scientific skills / competencies (and they have identified many fairly specific ones)   Include topics essential and relevant for modern biology.   Enhance interdisciplinarity.

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+In the summer of 2010, HHMI offered an opportunity to four universities:

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Create a proposal to develop prototype materials for biologists and pre-meds with a focus on scientific competency building and interdisciplinary links in

  Chemistry (Purdue)   Math (UMBC)   Physics (UMCP)   Capstone case study course (U of Miami)


+Goals of NEXUS: A national demonstration project   Create prototype materials

  An inventory of open-source instructional modules that can be shared nationally .

  Interdisciplinary   Coordinate instruction in biology, chemistry, physics, and math.

  Competency based   Teach generalized scientific skills so that it supports instruction in the other disciplines.

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+ AN APPROACH TO A SOLUTION

Opening lines of communications


+ Is there anything broken?   Lines of communication! It turns out there are

important cultural differences between how biologists and physicists view the class.

  Many biologists see most of the traditional introductory physics class as useless and irrelevant to biology – and the physicists claim that “we can apply physics to biology examples” as trivial and uninteresting.

  Physicists see a coherent structure with no room for change.

  Physics is an outlier in a biology curriculum. Lower division bio classes use no physics and (essentially) no upper division biology classes require physics as a prerequisite.

  The new MCAT will no longer do “traditional” physics questions.


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+Two views heard at a conference on interdisciplinary Science Education

1. Physicist: "This whole 'physics for biology’ idea makes me very uncomfortable. What's next? 'Physics for mechanical engineers’ or 'physics for electrical engineers'? Where does it end?

I could see maybe having a physics class for all students and then having a few tailored recitation sections where students focus on applications to their various fields, but I’m uncomfortable with 'physics for X' as an idea. We should be conveying how we view physics to everyone.”

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+Two views heard at a conference on interdisciplinary Science Education

2. Biologist: "I guess the physics for biologists idea may be a step in the right direction, but for it to be useful it has to go much further and be entirely revamped.

It has to be very narrowly focused on those ideas that biologists see as essential, not just removing a few topics. If I want to know about forces, I'll look it up, but it does not make sense for biology students to be spending time on that when they have profound problems with biology. Unfortunately, physicists generally have a profound ignorance about biology, so I'm not sure they are the right folks to be doing it. I can teach the relevant physics myself."

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+We put together are large team of stake-holders. The questions for discussion were:

  What starting assumptions should we make about our students?

  What content should we teach?

  What competencies should we focus on?

  What are the barriers to constructing an effective course?

  What do we need to do to create effective inter- or trans-disciplinary instruction?

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+After many interesting and illuminating discussions   We came to a better understanding

of what it was the biologists needed and how the disciplines perceived the world and their science differently.

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+Changing the culture of the course

  We seek content and examples that have authentic value as perceived by biology students.   We want upper division bio to make physics a pre-requisite.

  We do not assume this is a first college science course.   Biology, chemistry, and calculus are pre-requisites.

  We do not assume students will have later physics courses that will “make things more realistic.”   The value added by physics can’t wait until later classes.

  We choose different content from the traditional class, focusing on topics that are common to all biology majors   Atomic and molecular examples   Chemical energy   Motion in fluids   Random motion and its implications


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+And...   We continue to negotiate these changes

through extensive discussions among biologists, chemists, and physicists.

  We support and refine our approach through extensive qualitative and quantitative Physics Education Research .

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Throughout...   We (try to) maintain the crucial components

of “thinking like a physicist” – quantification, mathematical modeling, mechanism, multiple representations and coherence (among others).


+ SOME INTERESTING RESULTS

Modifying the IPLS class


+What can physics do for biology students that’s useful for them?   Put “legs under” complex topics introduced in

bio and chem through the use of “toy models.”   Fluids   Diffusion   Chemical reactions   Thermodynamics and statistical physics

  Help develop scientific skills that may be harder to build in intro chem and bio because of the complexity of the examples.   Learning the value of “toy models” (understanding the

simplest possible system well as a starting point)   Blending math with physical sense making


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+Revising the content   Expand

  Atomic and molecular models of matter

  Energy, including chemical energy

  Fluids, including fluids in motion and solutions

  Dissipative forces (drag & viscosity)

  Diffusion and gradient driven flows

  Kinetic theory, implications of random motion, statistical picture of thermodynamics

  Reduce substantially or eliminate entirely   Projectile motion   Universal gravitation   Inclined planes, mechanical

advantage   Linear momentum   Rotational motion   Torque, statics, and angular

momentum   Magnetism   Relativity

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Long-term goal: Have coverage of many more topics than can be covered so different instructors make make different choices.

+Revising the approach

  Be explicit about modeling and analyzing as systems.

  Emphasize equations as guides to thinking and reasoning

  Focus on coherent vs. random motion

  Develop quantification skills and a sense of scale

  Use modern pedagogical tools

  Give problems where building equations are the point

  Do problems with simulations, video, numerical calculations (solving ODEs on a spreadsheet)

  Do multiple labs on random motion

  Give estimation problems on macro & micro scales

  Create clicker and groupwork problems


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We want to So we

+The NEXUS/Physics materials

  The materials are on-line, modular, and open to all, including   A modular textbook or “wiki-book” of readings   A problem collection   Recitation-appropriate group-learning activities   A set of scientific community laboratories   A teacher’s guide to the content and pedagogy

(in progress)


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+New interdisciplinary topics


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  Focus on modeling and explicating assumptions.

  Do micro and macro examples throughout assuming students know about atoms and molecules.

  Include discussion of chemical energy and reactions

  Treat random motion as well as coherent. (Labs!)

  Carefully build the basic statistical mechanics support for thermodynamics (conceptually).

  Expand treatment of fluids and physics in fluids.

Dreyfus et al., Am. J. Phys 82:5 (2014) 403-411 Geller et al., Am. J. Phys 82:5 (2014) 394-402 Moore et al., Am. J. Phys 82:5 (2014) 387-393

+Example: The energetics of chemical bonding – Interdisciplinary reconciliation

  In introductory chemistry and biology classes, students learn about chemical reactions and the critical role of energy made available by molecular rearrangements.

  But students learn heuristics by rote that can feel contradictory to them and that they often don’t know how to reconcile.

1.  It takes energy to break a chemical bond. 2.  Breaking the bond in ATP is the “energy currency”

providing energy for cellular metabolism.


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W. C. Galley, J. Chem. Ed., 81:4 (2004) 523-525.

M. Cooper and M. Klymkowsky, CBE Life Sci Educ 12:2 (2013) 306-312

+Many students infer a “piñata” model of a chemical bond.

"But like the way that I was thinking of it, I don't know why, but whenever chemistry taught us like exothermic, endothermic, like what she said, I always imagined like the breaking of the bonds has like these little [energy] molecules that float out, but like I know it’s wrong. But that's just how I pictured it from the beginning."


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+Distinct disciplinary perspectives


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  Physicists and biologists (and chemists) make different tacit assumptions.

  Physicists tend to isolate a system to focus on a particular physical phenomenon and mechanism.

  Biologists (and chemists) tend to assume the natural and universal context of life – a fluid environment (air and water taken for granted).

  We learned to not try to condemn one or other perspective as “wrong” but to be explicit and discuss the different ways different disciplines look at the same phenomenon – and why.

+The NEXUS/Physics Chemical Energy Thread


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Dreyfus et al., Am. J. Phys 82:5 (2014) 403-411

+How can physics help?   Build a coherent story using toy models

  Bulldog on a skateboard

  Atomic interactions and binding

  Reactions in which bonds are first broken and then stronger ones formed (the Gauss gun)


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+ A series of clicker questions (PhET based) helps students get comfortable with negative PE and with the concept of binding energy.


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Same problems analyzed with shifted zero of PE – one positive E, one bound.

+Bound states HW problem

The skateboarder is just an analogy for the cases we are interested in -- interacting atoms.


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If the atoms have an energy of -7.5 units as shown by the solid line in the figure, would you have to put in energy to separate the atoms or by separating them would you gain energy? How much? Explain why you think so.

+The Gauss Gun: A classical analog for an exothermic reaction


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https://www.youtube.com/watch?v=zZmCJ5eZlmo

+Student drawing from a HW on the reaction H2 + O2 2H2O


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+Some more general student comments   “At first I was expecting the class to be like the biology calculus

class that did not focus on any biology. But, as the semester progressed I saw that the class was actually directed towards helping students to understand biological ideas using physics. “

  …[biology professors] have to go over so much stuff that they don't really take the time to go over why things happen. And I'm a very why kind of person I want to understand why does this happen? ...And you know [diffusion] was never explained to me very well, and then when I take this [physics] class and understand oh well this is why molecules interact the way they do.

  “I now see that physics really is everywhere, and the principles of physics are used to govern how organisms are built and how they function.”

  [In lab] “I learned how to approach a problem by designing our own experiments and interpreting data our own way. These labs taught me how to think for myself.”


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+IMPLICATIONS

What if we ...?


+At Maryland NEXUS/Physics has involved our biophysics research group in the creation and teaching of the class

  This has yielded exam, homework problems, and recitation activities tied to our local research (chemical signaling, forces on cells, motor proteins)

  Six NEXUS/Physics biology students (from our second year class of 30) became interested enough in biophysics and the quantitative approach to sign up for the biophysics group’s summer MATLAB bootcamp.

  Eight NEXUS/Physics biology students (and an equal number of physics majors) signed up for an upper level research class that carried out research at NIH mentored by NIH postdocs and using some of the tools they learned in our IPLS class.


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+Current universities testing NEXUS/Physics

  Purdue*   Montgomery College*   The College of New England (Maine)*   Swarthmore College   Florida State   Michigan State   Dickinson College   George Mason University   Elon College


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*Full implementation with labs

+The Long Term Plan   Create an AAPT on-line IPLS environment

(NSF proposal from AAPT and 7 collaborating universities)

  Use NEXUS/Physics as the core of a modular, on-line set of materials that can integrate readings, activities, and problems from multiple sources.

  This would be an open environment in which users could contribute their own materials, have them peer reviewed, and added to the collection.

  This gives the potential for a course that matches local (research) interests and opportunities.


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+ It’s been fun!   Rethinking intro physics in the biological context has been a blast.   Thinking about how to teach new physics – like the energy analysis of chemical bonds, diffusion, and free energy – at an intro level has been extremely interesting.   Seeing physics from the angle of other disciplines (biology, chemistry) has given us deeper insights into what we traditionally do – how we use models and the role of math.


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+The key to the process was carefully rethinking the class   Considering the long term goals in context

(where the students are in their curriculum)   Being willing to strike out in new directions

and not just make incremental changes   Focusing not just on content but also on

epistemology   Working to understand what attitudes and

expectations students bring into the class   Focusing on what epistemological resources

can be valuable for the students both at their level of development and for their future careers.


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+Let’s speculate

  What if we did this in other contexts?  Engineers?  Physics majors?


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+Engineers?

  Engineers very much tend to favor real-world examples. Why don't we do more "How good is this model?" and "How does this physics affect design?" (Design is a big deal for engineers.)

  Does “old” (19th century) physics suffice for modern engineers?


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+Physics majors?   When I finished my undergraduate

education (>50 years ago) I said that, "I learned everything about point particles and empty space and nothing about anything." That’s still mostly true.

  Today a very large fraction of our students are going to have careers in the physics of materials, atomic physics, optics, quantum computing, nano- and meso-scale physics and the like. Are our instructional paths for our majors appropriate for their current reality?


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+EPILOGUE


+The NEXUS Development Team (UMCP)

  Physicists   Joe Redish   Wolfgang Losert**   Chandra Turpen   Vashti Sawtelle   Ben Dreyfus*   Ben Geller*   Kimberly Moore*   John Gianini* **   Arnaldo Vaz (Br.)

  Biologists   Todd Cooke   Karen Carleton   Joelle Presson   Kaci Thompson

  Education (Bio)   Julia Svoboda   Gili Marbach-Ad   Kristi Hall-Berk*

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6/7/15 APS Dept. Chairs Conf. * Graduate student ** Biophysicist

+Discussants: UMCP co-conspirators   Physicists

  Arpita Upadhyaya**   Michael Fisher   Alex Morozov**   Peter Shawhan

  Biologists   Marco Colombini***   Jeff Jensen   Richard Payne   Patty Shields   Sergei Sukharev**

  Chemists   Jason Kahn***   Lee Friedman   Bonnie Dixon

  Education   Andy Elby (Phys)   Dan Levin (Bio)   Jen Richards (Chem)

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** Biophysicist *** Biochemist

+Off-campus collaborators   Physicists

  Catherine Crouch* (Swarthmore)

  Royce Zia* (Virginia Tech)

  Mark Reeves (George Washington)

  Lilly Cui & Eric Anderson (UMBC)

  Dawn Meredith (U. New Hampshire)

  Steve Durbin (Purdue)

  Biologists   Mike Klymkowsky*

(U. Colorado)

  Chemists   Chris Bauer*

(U. New Hampshire)   Melanie Cooper*

(MSU)

  Education   Janet Coffey

(Moore Foundation)   Jessica Watkins

(Tufts University)

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*NSF TUES project 6/7/15 APS Dept. Chairs Conf.

+References


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•  Reinventing physics for life science majors, D. Meredith & E. Redish, Physics Today, 66:7 (2013) 38-43.

•  NEXUS/Physics: An interdisciplinary repurposing of physics for biologists, E. Redish, et al., Am. J. Phys. 82:5 (2014) 368-377.

•  Toward better physics labs for future biologists, K. Moore, J. Giannini, & W. Losert, Am. J. Phys., 82:5 (May, 2014) 387-393.

•  Chemical energy in an introductory physics course for the life sciences, B. Dreyfus, B. Geller, J. Gouvea, V. Sawtelle, C. Turpen, & E. Redish, Am. J. Phys., 82:5 (2014) 403-411.

•  Entropy and spontaneity in an introductory physics course for life science students, B. Geller, B. Dreyfus, J. Gouvea, V. Sawtelle, C. Turpen, & E. Redish, Am. J. Phys. 82:5 (2014) 394-402.

•  Language of physics, language of math: Disciplinary culture and dynamic epistemology, E. Redish and E. Kuo, Science & Education (2015-03-14) doi:10.1007/s11191-015-9749-7.

For more and access to materials, see: http://nexusphysics.umd.edu

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Rethinking Introductory Physics for Life Science Students: A model