Week 3 Begins What is the underlying technology of the computer and software Note much is not in Baase book define technology define computer a general purpose machine Jackson mention Brooks Hamlet here define software the static description of a dynamic process to be instantiated at some point in time to solve a computational problem Turner define abstraction reduction of a problem space by removing all details appearing irrelevant to a solution implications define operating system roughly the program that gives basic services to other programs called applications that offer services to the user what operating systems are there What Problems can Computers Solve Goedel s incompleteness theorem consider the proposition using logic this statement cannot be proved true Assume its provable to be true then it s false Assume it is false cannot be proved true then it is true What s up with that Computers cannot store real numbers they count in binary numbers 0 1 10 11 100 floating point arithmetic is innacurate demo java program they estimate results of real valued problems Computers cannot represent continuous behavior smooth behavior when they err they might err catastrophically interpolation does not help us to see their behavior no reliability theory to assist professionals in estimating how good programs might be Hamlet Parnas Leveson etc For Week 4 Read Petroski Chapters 4 and 5 Baase assignment review exercise 4 3 and general exercise 4 15 be brief and to the point lists are useful before explanations review written exercise information on website