1. SCI 105.020 Scientific Inquiry The Big Picture: Science, Technology, Engineering, etc

2. Topics What is Science? Basic & Applied Research Science, Engineering, Technology : a car metaphor Is Computer Science Science?

3. Body Of Knowledge Does any body of knowledge qualified for science?  Science is knowledge about the real (physical) world  There is no other options than obeying the natural laws Scientific statements/theories are testable The tests are repeatable The theories are consistent among each other The knowledge body is growing forever: there is no end product

4. Organization Of Knowledge Intra-disciplinary growth  Physics Astrophysics, quantum physics, nuclear physics Theoretical, experimental, computational physics Interdisciplinary growth  Physical chemistry & chemical physics  Material sciences  Environmental sciences

5. Scientific Processes The Micro-process:  The six-step program The Macro-process  The Scientific Knowledge Acquisition Web (SKAW) (see attached illustration)

6. Methodology/Philosophy of Science Positivism: hypothesis-experiment-evaluation  Propose a possible explanation of how something works and then test it Falsification: theory-falsification-modification  Seeing a million swans that are white cannot prove that “all swans are white”, but finding one that is black disproves the theory Relativism: emphasizing the social factors in the conduct of science (to be continued)

7. Methodology/Philosophy (continued) Relativism  Science is assumed to be objective: prejudices of the scientist do not affect the results presented  Scientists are human “The scientist does not record everything he observes but only those things which the theories he accepts indicates significant”  Science is theory-laden: theories strongly influence how science is done  Relativists suggest that science is a problem- oriented endeavor that can effectively solve problems even if it does not explain objective reality

8. Basic & Applied Research Basic research (or pure science) is driven by the curiosity of the scientist  A wonder about a particular phenomenon: e.g., the evolution of the universe Applied research is done to solve a specific problem  Usually leads to new or improved technology, which is the practical application of scientific knowledge

9. Basic & Applied Research : An Illustration Nuclear Physics: Fundamental nature of matter Nuclear weapons Medical devices Reactors Resulting technologies Nuclear weapons Nuclear medicine Nuclear energy Applied research Basic research

10. An Automobile Metaphor

11. Basic & Applied Research : The Interactions Applied research relies on basic research to provide the underlying ideas Basic research affects the society through the results of related applied research Basic research can be empowered by new technologies made available by applied research  Biology is traditionally experimental  Computational biology/bioinformatics is very popular now with the state-of-the-art computing technologies

12. Is Computer Science Science? Definitions of Computer Science  The study of computers and the major phenomena that surround them  Computer science is the body of knowledge concerned with computers and computation. It has theoretical, experimental, and design components and include (1)theories for understanding computing devices, programs, and systems; (2)experimentation for the development and testing of concepts; (3)design methodology, algorithms, and tools for practical realization; and (4)methods for analysis for verifying that these realizations meet requirements

13. A Modified Definition The discipline of computing id the systematical study of algorithmic processes that describe and transform information: their theories, analysis, design, efficiency, implementation, and application. The fundamental question underlying all computing is “What can be (efficiently) automated?”

14. What Computer Scientists Do? Sub-areas in Computer Science  Algorithms and data structures  Programming languages  Architecture  Numerical & symbolic computation  Operating systems  Software methodology & engineering  Databases & information retrieval  Artificial intelligent & robotics  Human-computer interaction

15. Paradigms For The Discipline Theory (rooted in mathematics)  Characterize objects of study (definition)  Hypothesize possible relationships among them (theorem)  Determine whether the relationships are true (proof)  Interpret results Abstraction (or modeling) (rooted in experimental scientific method)  Form a hypothesis  Construct a model and make a prediction  Design an experiment and collect data  Analyze results Design (rooted in engineering)  State requirements  State specification  Design and implement the system  Test the system

16. The Role Of Programming Computer Science Programming However, programming is part of the standard practices of the discipline Programming languages are useful tools for gaining access to the distinctions of the discipline Programs are instructions to the computing devices written in programming languages  Data structures: the way to hold information in a program, e.g., a list of orders to an online bookstore  Algorithm: clearly specified way to process the information, e.g., process the order sequentially

17. Computer Algorithms Computer algorithms often involve obtaining input, performing a calculation, and producing output. An algorithm for converting from Fahrenheit to Celsius: 1. Display a message asking the user to enter a Fahrenheit temperature. 2. Obtain the input entered by the user. 3. Convert the user’s input into numerical form. 4. Calculate the equivalent Celsius temperature, using the formula C = (F – 32)  (5 / 9) 5. Convert the Celsius temperature into character form and display the result.

18. What Do Computers Do? A computer system is an integrated collection of hardware and software components Hardware refers to the electronics inside a computer Software consists of (O/S and application) programs that tell the hardware what to do

19. Object-Oriented Programming A software system (or a collection of programs that support a certain application) can be seen as an imaginary software machine  It is constructed from parts: software objects  Each object encapsulates scripts and information (think of algorithm and data structure): its responsibilities Information: an object needs to know Scripts: operations that an object needs to do  Example: a bicycle object may be responsible for Information: which gear it is in Operations: start, change to a certain gear as specified, stop

20. Responsibilities & Collaborations To fulfill one of its responsibilities, an object may need to ask other objects for help: collaborations Objects collaborate with one and other by means of message passing There are three elements in a message  Recipient  Operation  Additional information