SCI 105.020Scientific Inquiry

The Big Picture:Science, Technology, Engineering, etc

Topics

What is Science? Basic & Applied Research Science, Engineering, Technology: a car metaphor

Is Computer Science Science?

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 testableThe tests are repeatableThe theories are consistent among each otherThe knowledge body is growing forever: there

is no end product

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

Scientific Processes

The Micro-process: The six-step program

The Macro-process The Scientific Knowledge Acquisition Web (SKAW)

(see attached illustration)

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)

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

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

Basic & Applied Research: An Illustration

Nuclear Physics:

Fundamental nature of matter

Nuclear weapons

Medical devices

Reactors

Resulting technologies

Nuclear weapons

Nuclearmedicine

Nuclear energy

Applied research

Basic research

An Automobile Metaphor

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

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

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?”

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

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

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

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.

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

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

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