99 Fun Facts About Computer Science

A binary number uses only which two symbols?

Binary needs only 0 and 1 because a circuit just has to tell two states apart, such as a switch being off or on, which also resists electrical noise.

Which mathematician formalised the modern binary system in his 1703 Explication de l'Arithmétique Binaire?

Gottfried Leibniz's paper also discussed China: the Jesuit Joachim Bouvet had sent him I Ching hexagrams, which Leibniz read as binary numbers.

Which IBM computer beat Jeopardy! champions Ken Jennings and Brad Rutter in 2011?

Watson was named after IBM's first CEO, Thomas J. Watson, and it played the matches without being connected to the internet.

Why is 'byte' spelled with a y rather than as 'bite'?

Werner Buchholz respelled 'bite' in 1956 to avoid accidental mutation into 'bit'; early Stretch bytes held one to six bits, and IBM's System/360 later made eight standard.

George Boole introduced Boolean algebra, the basis of digital circuits, in which 1847 book?

The Mathematical Analysis of Logic was sparked by a public quarrel between De Morgan and Sir William Hamilton, and Boole expanded it into The Laws of Thought in 1854.

Whose 1937 master's thesis applied Boolean algebra to switching circuits?

Claude Shannon wrote it as an MIT student, and psychologist Howard Gardner called it possibly the most important, and most famous, master's thesis of the century.

Ada Lovelace's Note G of 1843, often called the first computer program, calculated what?

The Bernoulli numbers program was written for Babbage's Analytical Engine, which was never built, so it was not tested in Lovelace's lifetime.

What is the significance of 1815 in MIL-STD-1815, the US military's programming language standard?

Ada Lovelace's birth year numbers the standard for Ada, the language named after her, and its manual was approved on 10 December 1980, her birthday.

What kind of device did Turing's 1936 paper 'On Computable Numbers' introduce?

An abstract machine, later called the Turing machine, reads and writes symbols on an endless tape, and Turing used it to prove some problems no machine can ever solve.

Which electromechanical machine did Alan Turing design at Bletchley Park to help break Enigma?

The bombe took its name from the Polish bomba, an earlier device, while Colossus and its predecessor Heath Robinson attacked a different German cipher, Lorenz.

Alan Turing's portrait appeared on which Bank of England banknote from June 2021?

The £50 note came out on 23 June 2021, Turing's birthday, less than eight years after Queen Elizabeth II's posthumous royal pardon.

ENIAC, completed in 1945, is usually called the first what?

Programmable electronic computer is ENIAC's usual title, but Britain's secret Colossus was already running in 1944, so ENIAC is often called the first general-purpose one.

ENIAC was originally built to calculate what for the US Army?

Artillery firing tables were being worked out by hand, and ENIAC could compute a shell's trajectory in seconds instead of hours.

Roughly how many vacuum tubes did ENIAC contain by the end of its life in 1956?

ENIAC's 18,000 vacuum tubes let it run at electronic speed, with no mechanical parts slowing its calculations.

Grace Hopper popularised which term after her team found a moth in a relay of the Harvard Mark II in 1947?

Debugging and 'bug' already existed as engineering slang, which is why the operators' log joked that the moth was the first actual case of a bug being found.

Grace Hopper's FLOW-MATIC language was the main ancestor of which business language that is still in use?

COBOL inherited FLOW-MATIC's English word commands, which Hopper introduced because business customers refused to learn symbols.

What kind of program was Grace Hopper's 1952 A-0 System, often called the first of its kind?

A compiler was the name for A-0 then, though it worked more like a linker, and Hopper said nobody would touch it because computers 'could only do arithmetic'.

Which element did Bardeen and Brattain use to build the first working transistor at Bell Labs in 1947?

Germanium carried the first point-contact transistor in December 1947, and Bardeen, Brattain and Shockley shared the 1956 Nobel Prize in Physics for it.

What is the most numerously manufactured artificial object in history?

The MOSFET transistor passed an estimated 13 sextillion units by 2018, since a single memory chip or microprocessor can hold billions of them.

Moore's law says the number of transistors on a chip doubles roughly how often?

Every two years was Gordon Moore's 1975 revision of his 1965 forecast of every year, and the 'law' is an observed trend, not a law of physics.

Which company did Gordon Moore, of Moore's law, co-found?

Intel was founded in 1968 by Moore and Robert Noyce, who had left Fairchild Semiconductor, the startup they had helped found as two of the 'traitorous eight'.

Which characters got through in the first ARPANET message of 29 October 1969 before the crash?

LO got through because the system crashed after the first two letters of LOGIN, and the full login worked about an hour later.

On 1 January 1983, 'flag day', the ARPANET switched to which protocol suite that still runs the internet?

TCP/IP replaced the older NCP on flag day, when the new protocols were permanently switched on, and the ARPANET itself was decommissioned in 1990.

Which symbol did Ray Tomlinson choose in 1971 to separate the email user from the host?

The at sign was chosen because usernames never used it and it already read as 'at', so an address says user at host, the format email still uses.

Tim Berners-Lee invented the World Wide Web while working at which institution?

He wrote the first browser, called WorldWideWeb, by the end of 1990, and CERN made the code royalty-free in April 1993.

Tim Berners-Lee ran the first web server on a NeXT computer, from the company founded by whom?

Steve Jobs founded NeXT in 1985 after leaving Apple, and Apple's 1997 purchase of NeXT brought him back to the company.

Which university student released a Unix-like kernel on 17 September 1991?

Linus Torvalds wanted to call it Freax, but his friend who ran the FTP server hosting it named the folder Linux, and the name stuck.

Which smartphone operating system is built on a modified version of the Linux kernel?

Android began as an operating system for digital cameras, and its startup switched to phones in 2004, a year before Google bought it.

Which Apple computer was introduced by the famous '1984' Super Bowl commercial?

Macintosh's launch ad was directed by Ridley Scott and showed an athlete hurling a hammer into Big Brother's screen as a blow against conformity.

Unlike most languages, Python marks blocks of code using what?

Indentation is part of Python's syntax, and the language itself is named after Monty Python's Flying Circus, not the snake.

Why was Java originally called Oak?

An oak tree stood outside its designer's office, James Gosling's, and the language was renamed Java before Sun released version 1.0 in 1996.

Which company owns the official implementation of Java, having bought Sun Microsystems in 2010?

Oracle completed its purchase of Sun on 27 January 2010, and Java's creator James Gosling resigned that April.

Which British computer scientist developed Quicksort in 1959?

Tony Hoare devised it as a British Council exchange student at Moscow State University, where he needed to sort words for a machine-translation project.

What is quicksort's worst-case running time on n items?

O(n²) comes from badly unbalanced partitions, such as already-sorted input with a poor pivot choice, yet on random data quicksort is typically slightly faster than merge sort.

How much prize money does the Clay Mathematics Institute offer for a proof settling P versus NP?

US$1 million is offered for each of seven Millennium Prize Problems, and Grigori Perelman turned his down after solving the Poincaré conjecture.

The security of RSA encryption rests on the difficulty of doing what?

Factoring a product of two big primes is slow while multiplying them is fast, so the primes stay secret even when their product is public.

Which British agency's mathematician, Clifford Cocks, secretly invented an RSA-equivalent system in 1973, four years before RSA was published?

GCHQ kept Clifford Cocks's scheme classified until 1997, so the public credit went to Rivest, Shamir and Adleman, whose initials name RSA.

Which reigning world chess champion did IBM's Deep Blue beat in a 1997 match?

Garry Kasparov had won their 1996 match 4–2, and after losing the 1997 rematch he suggested humans had helped the machine, which IBM denied.

How many chess positions per second could Deep Blue evaluate?

200 million positions a second helped the 1997 Deep Blue become the first computer to beat a reigning world chess champion in a match.

The Turing test, proposed in Turing's 1950 paper, judges a machine on what?

Human-like conversation is judged over typed messages, as an interrogator tries to tell machine from person in what Turing called the imitation game.

Why did many older programs risk treating the year 2000 as 1900?

They stored years as two digits to save scarce memory, so 1985 was kept as 85 and software could not tell 2000 from 1900.

The Year 2038 problem will hit systems that store Unix time in what kind of variable?

A signed 32-bit integer runs out of seconds on 19 January 2038 and wraps back to 13 December 1901, while 64-bit time pushes the limit about 292 billion years away.

What is a four-bit unit of data called?

A nibble is half a byte, its name a play on 'bite', and each nibble maps onto exactly one hexadecimal digit.

How many distinct values can a single eight-bit byte represent?

256 values run from 0 to 255, which is why each of the four numbers in an IPv4 address stops at 255.

Which device did the 1968 'Mother of All Demos' show off?

The computer mouse Douglas Engelbart used in San Francisco steered a computer back at SRI, 30 miles away.

Who led the Harvard Mark I programming staff that Grace Hopper joined during World War II?

Howard Aiken conceived the Mark I, which IBM built and shipped to Harvard in 1944, where Hopper became one of its first programmers.

What kind of malware did the 2017 WannaCry attack that hit NHS hospitals spread?

Ransomware locks a victim's files until a payment is made, and a researcher halted WannaCry within hours by registering the domain its hidden kill switch checked.

Alan Turing died on 7 June 1954 at the age of 41 from what?

Cyanide poisoning was ruled suicide, though his mother believed it was an accident from a chemistry experiment, and a half-eaten apple lay beside his bed.

Which programming language's classic 1978 book by Kernighan and Ritchie popularised the 'hello, world' program?

C's creator Dennis Ritchie co-wrote the book, though Brian Kernighan had already used 'hello, world' in a 1972 tutorial for the earlier language B.

Which Hollywood actress co-invented a frequency-hopping radio guidance system for torpedoes during World War II?

Hedy Lamarr devised it with composer George Antheil and patented it in 1942, but the US Navy rejected it as too bulky. Similar spread-spectrum ideas now protect wireless networks.

The world's first webcam was set up at the University of Cambridge in 1991 to watch which object?

A coffee pot in the Trojan Room was filmed so that researchers elsewhere in the building could avoid a wasted trip to an empty jug. The camera stayed on until 2001.

Ada Lovelace, often called the first computer programmer, was the only legitimate child of which Romantic poet?

Lord Byron separated from her mother a month after Ada was born. She was taught mathematics from an early age partly to root out any trace of his supposed insanity.

Under a 1998 April Fools' internet standard, a server replying with HTTP status code 418 claims to be what?

A teapot is the punchline of RFC 2324, published on 1 April 1998. When a standards chair tried to scrub code 418 from software in 2017, a 15-year-old's 'Save 418' campaign went viral and it stayed.

Which breakfast cereal's toy whistle produced the 2600-hertz tone that 'phone phreaks' used to make free calls?

Cap'n Crunch whistles gave phreaker John Draper his alias, Captain Crunch. Their pitch happened to match the tone AT&T used to signal that a trunk line was free.

Which search engine began in 1996 as BackRub, a research project by two Stanford University PhD students?

Google took its eventual name from a misspelling of 'googol', the number written as a 1 followed by 100 zeros, to suggest how much of the web it meant to search.

Which wireless technology takes its name from a tenth-century king who united Denmark's tribes into one kingdom?

Bluetooth was the nickname of King Harald, and the technology's logo fuses the runes for his initials, H and B. An engineer picked the name because it would unite communication standards as Harald united tribes.

Which term for a hidden software feature was coined at Atari after Warren Robinett hid his name in Adventure?

Easter egg was the label an Atari software director gave Robinett's secret credit, likening it to an egg hunt. Atari kept programmers' names off its games so rivals could not poach them.

Which three-key shortcut did engineer David Bradley design to restart the original IBM PC without switching off?

Ctrl+Alt+Del was Bradley's second choice. His first, Ctrl+Alt+Esc, proved too easy to bump by accident on the left side of the keyboard, rebooting the computer.

Dutch programmer Guido van Rossum named the language he created in tribute to which British comedy troupe?

Monty Python jokes run through the language's tutorials, where sample code uses 'spam' and 'eggs' as placeholder names instead of the traditional 'foo' and 'bar'.

Which Englishman, often called the 'father of the computer', designed the Difference Engine in the 1820s?

Charles Babbage never saw the machine completed, but a Difference Engine built from his original plans in 1991 worked as intended.

Which 1804 invention gave the Analytical Engine, a Victorian design for a mechanical computer, its punched cards?

The Jacquard loom wove patterns by reading a chain of punched cards laced together, and the Analytical Engine was meant to take in its programs and data the same way.

Tux, the official mascot of the Linux kernel, is which kind of animal?

A penguin was picked after the kernel's creator was nibbled by one at a zoo in Canberra in 1993. Artist Larry Ewing drew the final Tux using an early version of the free graphics program GIMP.

Which fictional computer sings 'Daisy Bell' as it is shut down in the film 2001: A Space Odyssey?

HAL 9000 sings it as a nod to real history: 'Daisy Bell' was the first song ever sung by a computer, an IBM machine that author Arthur C. Clarke had seen demonstrated.

The word 'robot' entered English from R.U.R., a 1920 science fiction play written in which language?

Czech gave the play its 'robota', a word for the forced labour serfs owed their masters. Author Karel Čapek credited his brother Josef with inventing 'robot'.

Which name appears as the author of the 2008 white paper 'Bitcoin: A Peer-to-Peer Electronic Cash System'?

Satoshi Nakamoto is a pseudonym, and the identity of the person or group behind it has never been confirmed. The smallest unit of a bitcoin, one hundred-millionth of a coin, is called a satoshi.

Which Roman general gives his name to the simple cipher that shifts every letter a fixed number of places?

Julius Caesar shifted each letter three places to protect military messages, so A became D. A shift of 13, known as ROT13, later hid joke punchlines and spoilers on Usenet.

In which US city did Bill Gates and Paul Allen found Microsoft in 1975, near the maker of the Altair 8800?

Albuquerque was home to MITS, whose Altair 8800 ran the pair's first product. Microsoft left for the Seattle area in 1979 because top programmers were hard to recruit to New Mexico.

Which language-learning app did CAPTCHA pioneer Luis von Ahn co-found with his graduate student Severin Hacker?

Duolingo followed his reCAPTCHA, which put the tests to work by having web users decipher words from old books that scanning software could not read.

Which image format, created at CompuServe in 1987, started a lasting argument over how to pronounce its name?

GIF was meant to be said with a soft g, its lead creator insisted, echoing the peanut butter brand Jif. Polls have generally found that more people say it with a hard g.

Which MIT programmer led the team that wrote the on-board flight software for NASA's Apollo Moon missions?

Margaret Hamilton is credited with coining the term 'software engineering' while doing the job, and in 2016 she received the Presidential Medal of Freedom for her Apollo work.

Which engineer designed the Apple I and Apple II computers after working on calculators at Hewlett-Packard?

Steve Wozniak went back to Berkeley in 1981 to finish his degree, enrolling as 'Rocky Raccoon Clark' because his real name had become too well known.

Which language did Brendan Eich write in about ten days at Netscape in 1995 to run inside web browsers?

JavaScript was first called Mocha, then LiveScript. The final name arrived that December in a joint announcement with Sun Microsystems.

Which German engineer completed the Z3 in Berlin in 1941, a relay-based computer programmed with punched film?

Konrad Zuse asked the German government for money to swap the relays for electronic switches, but was refused because the work was deemed 'not war-important'. Allied bombs destroyed the Z3 in 1943.

Which computer did Post Office engineer Tommy Flowers design to help crack Germany's wartime Lorenz cipher?

Colossus stayed an official secret until the mid-1970s, so its builders went uncredited for decades and it had little direct influence on the computers that followed.

Which DeepMind program beat champion Lee Sedol four games to one in a Seoul match in March 2016?

AlphaGo won all but the fourth game of the ancient board game Go, and Korea's professional association awarded the program an honorary top rank of 9-dan.

Which NASA probe was lost in 1999 because its builder's software used pound-force where NASA expected metric units?

Mars Climate Orbiter flew too close to the planet and was destroyed in its atmosphere. NASA accepted the blame for failing to run the checks that would have caught the mismatch.

Which block-based visual programming language from the MIT Media Lab was built to teach children to code?

Scratch takes its name from the way disc jockeys scratch vinyl records, because the site lets children mix and 'remix' graphics, sounds and each other's programs.

Which computer worm, uncovered in 2010, is blamed for wrecking uranium centrifuges at Iran's Natanz nuclear plant?

Stuxnet is widely reported to be a joint American and Israeli cyberweapon built under the codename Operation Olympic Games, though neither country has openly admitted responsibility.

Grace Hopper handed audiences 30-centimetre pieces of wire to show how far light travels in which unit of time?

A nanosecond was her answer when generals asked why satellite messages took so long. She contrasted the short wires with a 300-metre coil standing for a microsecond.

Which mathematician wrote the 1945 'First Draft of a Report on the EDVAC', describing a stored-program computer?

John von Neumann wrote it by hand on train journeys to Los Alamos. Because the draft listed no other authors, he alone got the credit for a design shared with the machine's engineers.

Which computer predicted Eisenhower's landslide live on CBS on election night 1952 from a small sample of votes?

UNIVAC I called the landslide so early that CBS held the forecast back and viewers were first told the race looked close. Late that night the network admitted the machine had been right for hours.

Which language did John Backus's IBM team deliver in 1957 as a practical alternative to assembly code?

Fortran owed its existence to laziness, its creator joked: Backus disliked writing programs for missile trajectories by hand and wanted a system that made the job easier.

Which language did John Kemeny and Thomas Kurtz create at Dartmouth College in 1964 for non-science students?

BASIC ran its first program at 4 a.m. on 1 May 1964. Its creators also built a time-sharing system so that many students could use one computer from separate terminals at once.

Niklaus Wirth named which 1970 programming language after a 17th-century French mathematician and philosopher?

Pascal was designed to encourage good programming practice. Wirth wrote it after his proposal for a successor to ALGOL was not accepted and the committee's work bogged down.

Which database query language did Donald Chamberlin and Raymond Boyce design at IBM's San Jose lab in the 1970s?

SQL began life as SEQUEL, which is why many people pronounce it that way. The name was shortened because a British engineering firm already held 'SEQUEL' as a trademark.

Which company's Palo Alto Research Center introduced the Alto, a pioneering graphical desktop computer, in 1973?

Xerox built Altos only in limited numbers. After Apple staff were given demonstrations in 1979, in return for Xerox buying Apple stock options, the ideas reached the mass market in Apple's computers.

Which networking technology did Robert Metcalfe name in a 1973 memo and later sell by co-founding 3Com?

Ethernet was named after the 'luminiferous aether', the invisible medium once believed to fill the universe and carry light. The memo called the idea 'The Ether Network'.

Which internet system, created by Paul Mockapetris in 1983, turns names like example.com into IP addresses?

DNS replaced a single text file, HOSTS.TXT, that the Stanford Research Institute maintained to map every ARPANET computer's name to its address. It is often called the internet's phone book.

Which 1993 web browser from the University of Illinois's NCSA was the first to show images inline with text?

Mosaic was instrumental in popularising the web. Its lead developer, Marc Andreessen, went on to co-found the company that built Netscape Navigator, which soon took most of its users.

Which programmer launched the GNU Project in 1983 and founded the Free Software Foundation two years later?

Richard Stallman had met the problem first-hand: in 1980 his MIT lab was refused the source code for a new laser printer, so he could not add the paper-jam alerts he had written for the old one.

Which Stanford professor wrote The Art of Computer Programming and created the TeX typesetting system?

Donald Knuth built TeX because he was so frustrated by how the new phototypesetting made his own volumes look that he took time out to solve digital typesetting himself.

Which 1971 program, often called the first computer worm, hopped between ARPANET mainframes and was hunted by Reaper?

Creeper did no damage: it only printed 'I'M THE CREEPER : CATCH ME IF YOU CAN' on a teletype. Reaper, written to eliminate it, is regarded as the first antivirus software.

Whose punched-card tabulating machines processed the 1890 US census, founding a business that became part of IBM?

Herman Hollerith's machines helped cut the time needed to process the census from eight years to six, despite a larger population and more questions to tabulate.

Which 1982 home computer does Guinness World Records list as the best-selling desktop computer model of all time?

Commodore 64 sales are estimated at between 12.5 and 17 million units. The machine took its name from its 64 kilobytes of memory and went on sale for US$595.

Which 1960s chatbot did MIT's Joseph Weizenbaum write to imitate a psychotherapist questioning a patient?

ELIZA was named after Eliza Doolittle of Pygmalion. Its creator was startled when his own secretary reportedly asked him to leave the room so that she could talk to the program alone.

Which neural network architecture did the 2017 research paper 'Attention Is All You Need' introduce?

Transformer models became the main architecture behind large language models. The paper's title is a reference to the Beatles song 'All You Need Is Love'.

Which American logician invented the lambda calculus and supervised Alan Turing's doctorate at Princeton?

Alonzo Church showed in 1936 that some problems cannot be solved by any mechanical method, shortly before Turing proved the same by another route. Turing then enrolled at Princeton to study under him.

Which Texas Instruments engineer built the first integrated circuit in 1958 and later shared a Nobel Prize?

Jack Kilby worked it out in the summer of 1958 because, as a newly hired engineer, he had no right to a holiday yet. He later co-invented the handheld calculator.

Which 'father of supercomputing' designed a 1976 machine shaped like a C and ringed with benches?

Seymour Cray bent the chassis into a C so that the wires on its inner edge could be shorter, speeding the machine up. The benches around it hid the power supplies and cooling system.