• Some Funny Things Happened on the Way to the Moon [PDF], Richard H. Battin, 1989.
• One Giant Leap: The Apollo Guidance Computer, Dag Spicer, from Dr. Dobb's Journal. (Includes computer specs.)
• Moore's Law
• Augusta Ada Byron

• ENIAC Story (like most ENIAC histories, it is wrong about ENIAC being the "world's first electronic digital computer" — we'll learn why before PS4)
• USS Hopper
• Remembering Grace Murray Hopper: A Legend in Her Own Time, by Elizabeth Dickason.
• John Backus biography
• Keynote Speech, First Grace Hopper Conference by Anita Jones

• Why Verb-Initial Languages are Not Frequent [PDF], André Grüning, May 2002. Interesting paper that speculates on why most natural languages are SOV or SVO using results from computer simulations.
• Revised⁵ Report on the Algorithmic Language Scheme [PDF] - this is the official definition of the Scheme language
• C++ Standard Core Language Active Issues (529 issues or problems with C++ that the language experts can't agree on)

• Listen to Bach's Little Harmonic Labyrinth (MIDI file); More GEB Music from VCU course
• GNU's Not Unix (GOD Over Djinn-like acronym)
• Richard Stallman

• The Story of Benoit B. Mandelbrot and the Geometry of Chaos

• Science's Endless Golden Age by Neil Tyson

Quicker Sorting
Some Useful Code From Class

• Tyson's speech to the State Department

Sir Tony Hoare developed the QuickSort algorithm in 1960. His first assignment at a job with a small computer manufacturer was to implement a sorting routing based on the best then-known algorithm (Shell Sort, which is a Θ(n²) algorithm that is a slight improvement on the InsertSort alrogithm we saw in class). He thought he could do better, and his boss bet him sixpence that he couldn't. Quicksort was the algorithm that resulted. Since it is Θ(n log n) on average, it is clearly better than Shell Sort theoretically (that is, it is always eventually faster once n is large enough), and is also better than Shell Sort in practice for nearly all applications.

Hoare received the 1980 Turing Award (the highest award given in Computer Science, it is named for Alan Turing, one of the codebreakers who worked at Bletchley Park during WWII. We will learn about Turing's contributions to Computer Science after Spring Break) for contributions to the design of programming languages. His award speech, The Emperor's Old Clothes, presents principles from his experiences designing programming languages. One of his claims is,

I conclude that there are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies and the other way is to make it so complicated that there are no obvious deficiencies.

Here's how Alan Kay describes his first assignment in graduate school:

Head whirling, I found my desk. On it was a pile of tapes and listings, and a note: "This is the Algol for the 1108. It doesn't work. Please make it work." The latest graduate student gets the latest dirty task.

The documentation was incomprehensible. Supposedly, this was the Case-Western Reserve 1107 Algol--but it had been doctored to make a language called Simula; the documentation read like Norwegian transliterated into English, which in fact it was. There were uses of words like activity and process that didn't seem to coincide with normal English usage.

Finally, another graduate student and I unrolled the program listing 80 feet down the hall and crawled over it yelling discoveries to each other. The weirdest part was the storage allocator, which did not obey a stack discipline as was usual for Algol. A few days later, that provided the clue. What Simula was allocating were structures very much like the instances of Sketchpad. There were descriptions that acted like masters and they could create instances, each of which was an independent entity. What Sketchpad called masters and instances, Simula called activities and processes. Moreover, Simula was a procedural language for controlling Sketchpad-like objects, thus having considerably more flexibility than constraints (though at some cost in elegance) [Nygaard, 1966, Nygaard, 1983].

This was the big hit, and I've not been the same since.

Alan Kay, The Early History of Smalltalk, 1993.

• Aristotle's Logic
• Gödel's Incompleteness Theorem — several short explanations of what Gödel proved
• Around Gödel's Theorem — hyper-textbook by Karlis Podneiks
• On Formally Undecidable Propositions Of Principia Mathematica and Related Systems [PDF] — Gödel's original paper.

In connection with the interview for his US citizenship, Gödel once told me that for this occasion he had studied how the Indians had come to America. Einstein and O.Morgenstern were his witnesses, and Morgenstern has told different people about aspects of the event. The following account is given by H-Zemanek and E.Kvhler. Even though the routine examination G was to take was an easy matter, G prepared seriously for it and studied the US Constitution carefully. On the day before the interview G told Morgenstern that he had discovered a logical-legal possibility of transforming the United States into a dictatorship. Morgenstern saw that the hypothetical possibility and its likely remedy involved a complex chain of reasoning and was clearly not suitable for consideration at the interview. He urged G to keep quiet about his discovery. The next morning Morgenstern drove Einstein and G from Princeton to Trenton. Einstein was informed; on the way he told one tale after another, to divert G from his Constitution-theoretical explanations, apparently with success. At the office in Trenton, the official in charge was Judge Philip Forman, who had inducted Einstein in 1940 and struck up a friendship with him. He greeted them warmly and invited all three to attend the (normally private) examination of G.
The judge began, "You have German citizenship up to now." G interrupted him, "Excuse me sir, Austrian." "Anyhow, the wicked dictator! but fortunately that is not possible in America." "On the contrary," G interjected, "I know how that can happen." All three joined forces to restrain G so as to turn to the routine examination.
From Hao Wang, Reflections on Kurt Gödel.

Years ago, the Princeton physicist John Wheeler began to wonder whether Heisenberg's uncertainty principle might not have some deep connection to Gödel's incompleteness theorem (probably the second most misunderstood discovery of the 20th century). Both, after all, seem to place inherent limits on what it is possible to know. But such speculation can be dangerous. "Well, one day [Wheeler recounts] I was at the Institute of Advanced Study, and I went to Gödel's office, and there was Gödel. It was winter and Gödel had an electric heater and had his legs wrapped in a blanket. I said, 'Professor Gödel, what connection do you see between your incompleteness theorem and Heisenberg's uncertainty principle?' And Gödel got angry and threw me out of his office."
Jim Holt, Uncertainty About the Uncertainty Principle: Can't anybody get Heisenberg's big idea right?,
Slate, 6 March 2002.

• Alan Turing
• On Computable Numbers, with an Application to the Entscheidungsproblem — Turing's original (1936) paper that introduced the Halting Problem (tougher to read than Gödel's)
• Breaking the Code — movie about Alan Turing
• Halting Problem D-League Hockey Team (Statistics)
• Time 100: Alan Turing

There is a remarkably close parallel between the problems of the physicist and those of the cryptographer. The system on which a message is enciphered corresponds to the laws of the universe, the intercepted messages to the evidence available, the keys for a day or a message to important constants which have yet to be determined. The correspondence is very close, but the subject matter of cryptography is very easily dealt with by discrete machinery, physics not so easily.
Alan Turing

• Mark W. Eichin and Jon A. Rochlis, With Microscope and Tweezers: An Analysis of the Internet Virus of November 1988, IEEE Symposium on Security and Privacy, 1989.
• The Art of Computer Virus Research and Defense, Peter Szor (One Page Review in IEEE Security and Privacy, by Nathanael Paul, UVa student)

The behaviour of the computer at any moment is determined by the symbols which he is observing. and his “state of mind” at that moment. We may suppose that there is a bound B to the number of symbols or squares which the computer can observe at one moment. If he wishes to observe more, he must use successive observations. We will also suppose that the number of states of mind which need be taken into account is finite. The reasons for this are of the same character as those which restrict the number of symbols. If we admitted an infinity of states of mind, some of them will be “arbitrarily close” and will be confused. Again, the restriction is not one which seriously affects computation, since the use of more complicated states of mind can be avoided by writing more symbols on the tape. ...

We may now construct a machine to do the work of this computer. To each state of mind of the computer corresponds an “m-configuration” of the machine. The machine scans B squares corresponding to the B squares observed by the computer. In any move the machine can change a symbol on a scanned square or can change anyone of the scanned squares to another square distant not more than L squares from one of the other scanned squares. The move which is done, and the succeeding configuration, are determined by the scanned symbol and the m-configuration....

Alan Turing, On computable numbers, with an application to the Entscheidungsproblem, 1936.

• The Early History of Data Networks, Gerard J Holzmann Björn Pehrson.
• A Brief History of the Internet
• Hobbe's Internet Timeline
• A Paternity Dispute Divides Net Pioneers, New York Times, 8 November 2001. (Fighting over who deserves credit for inventing packet switching, need to pay to see full article).
• Al Gore and the Internet Resources
• Al Gore and the Creation of the Internet (includes Robert Kahn and Vinton Cerf's statement)

• Passwords: The Weakest Link?, cNet News, 22 May 2002.
• Dos and Don'ts of Client Authentication on the Web, Kevin Fu, Emil Sit, Kendra Smith, Nick Feamster. USENIX Security Symposium, 2001.

• Molecular structure of Nucleic Acids, James Watson and Francis Crick. Nature, 25 April 1953. [ PDF]
• National Human Genume Research Institute (Director: Francis Collins)
• James Shreeve, The Genome War: How Craig Venter Tried to Capture the Code of Life and Save the World, 2004.
• White House Announcement, June 26, 2000.

• R.L. Rivest, A. Shamir, L. Adleman. A Method for Obtaining Digital Signatures and Public-Key Cryptosystems, 1978. This is the original RSA paper, perhaps the most important paper in any field in the last 30 years. You should read it in the Rotunda or a lawn garden some time this summer.
• Whitfield Diffie and Martin Hellman. New Directions in Cryptography, 1976.
• Junger decision allowing publication of RSA source code
• The Primes Pages
• http://crl.verisign.com/ - VeriSign's Certificate Revokation List
• Microsoft, VeriSign, and Certificate Revocation , by Gregory L. Guerin (Schneier's original article)
• Ten Risks of PKI: What You're Not Being Told About Public Key Infrastructure, C. Ellison and B. Schneier. Computer Security Journal, v 16, n 1, 2000.

• SETI@home (finding aliens)
• Other distributed computing projects: Einstein@Home (finding spinning neutron stars), Climate Prediction, Rosetta@home (protein folding and design), distributed.net (mostly breaking encryption), folding@home (Stanford protein folding)
• RUI: Ensuring Computation Integrity in Distributed Volunteer Computing Platforms, Doug Szajda, Bary Lawson, Jason Owen [Paper on catching cheaters with fake tasks, Catching cheaters with multiple tasks