Last weeks topics – lab reflections: Scientific Method Idea: Use observations to predict the future Definition: A scientific method consists of the collection of reproducible data through observation , and the formulation and testing of scientific models which predict these observations. Uncertainties Design Flaws, Measurement Uncertainty, Chaos (waterwheel) Testing Hypothesis is correct, if model prediction is within the error bar.

This weeks topic: -Understanding Base Concepts Reflections on the lab: -Customary Units / SI Units Outlook: Solids / Fluids / Gases

What is Understanding? Student responses:

Understanding Definition: To understand = being able to translate Antonym: being confused Understanding Spanish = being able to translate from and to English Practical Understanding of Physics = match real world phenomena with Physics concepts Conceptual networks:

Understanding a base concept = Matching a base concept with a real world phenomena (practical understanding) Relating a base concept to more abstract concepts (abstract understanding, theoretical understanding) Translating a base concept into algebra (mathematical understanding) And so on

Algebra to Go, Houghton-Mifflin What is a concept? Answer: Topic #1, Concept, Concept Icon 1. Objective (brief)- create a relation to a very well known concept: keywords, typical tasks, one typical example 2. Introduction/Context (detailed)- create more relations to better known concepts: context keywords, task keywords, typical situations, typical tasks in more detail, contrast from other concepts. 3. Definition of the Concept: a) list of situations, list of sub concepts, e.g. Physics b) recipe, measurement algorithm for quantity, e.g. probability of an event c) relation between sub concepts, e.g. theoretical probability 4. Illustration use clean graphical models (light bulb) Definition of a concept Algebra to Go, Houghton-Mifflin

5. Discussion: a) When is it constant? When does it apply? (“equally-likely outcomes”) b) Other definitions, corollaries, does the magnitude have a special name? c) Synonyms, antonyms, homonyms, inverses d) Is it additive, when is it additive? How does it spread?(evenly: such as tension in a string, heat in a material, or like a flow: current)? How to compare (two forces)? How to calibrate? e) units f) how to measure, how to test it? g) largest, smallest, typical, benchmarks h) how to produce it at home, how is it used commercially 6. Examples: a) single concept b) single concept used twice: ratios, comparisons, iterations c) single concept with one set of substitutions: substitute inputs (such as units), compute differences, use the definition of a sub concept. d) double concept: (i) other physics concept (ii) common knowledge concept (iii) concept from other discipline e) ask for formal solutions for all of the above 7. Translations: a) derive within the discipline b) translate into other disciplines c) fully substitute

Solids, Fluids, and Gases rock, wood, water ice, dry ice (ball) atoms are close, most rigidly packed and do not change position => definite volume elastic = returns to original shape after being squeezed or stretched => definite shape Liquids: water, oil, clay, liquid nitrogen (vases) atoms are close, densely packed, and change position => definite volume viscous = does not return to original shape after being squeezed or stretched => no definite shape Gas: vapor, air, oxygen gas, nitrogen gas atoms are far apart and change position => no definite volume (N2 cannon) Simulation

-Understanding Base Concepts This weeks topic: -Understanding Base Concepts [1] L. J. Durak and A. Hübler. Scaling of knowledge in random conceptual networks. Lecture Notes in Computer Science 2074, 976-985 (2001). [2] A. Hübler, Understanding Complex Systems: Defining an abstract concept. Complexity 12(5), 5-9(2007). Outlook: Solids / Fluids / Gases I have research opportunities in my lab.

What is Understanding? Student responses: You can demonstrate it Know how it works - Can explain it to somebody else - Can make accurate predictions - Can use skills or concepts to solve different problems - Being able to say it back in my own words - Can be tested on it - Not confused about it - Being confident about what I am doing - Having no more questions - When I can do myself, without help - You can reason why it is a certain way and not another - When you completely get it - When you can apply it to other situations - When you can compare it or relate it to something else that you already know - When you understand another person, you know where they are coming from - Experiencing something for yourself, so you know what its like - Not understanding = speaking a different language, using different concepts