50 Fun Facts About Computer Science

A binary number uses only which two symbols?

Each digit is a bit, and eight of them make a byte that can hold any value from 0 to 255.

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

A Jesuit correspondent showed him the Chinese I Ching had arrived at binary notation independently, centuries earlier.

Who coined the word 'byte' in 1956 while designing IBM's Stretch computer?

He deliberately spelled it with a y so it could not be mistyped into 'bit'; a half-byte is a nibble.

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

Eight bits became the standard byte with the IBM System/360 in the 1960s.

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

His 1854 Laws of Thought expanded it; the term 'Boolean algebra' was only coined by Henry Sheffer in 1913.

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

He was 21, and the thesis has been called the most important master's thesis of the century.

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

It was written for Babbage's Analytical Engine, which was never built; she was the daughter of the poet Lord Byron.

What is the significance of 1815 in the Ada programming language's standard number MIL-STD-1815?

She died in 1852 at 36, having described her approach to mathematics as 'poetical science'.

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

It was 36 pages long and gave a precise definition of what it means for something to be computable.

At Bletchley Park, Turing designed an electromechanical machine to break Enigma. What was it called?

The name came from the Polish bomba kryptologiczna, an earlier machine his design improved on.

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

It was released on his birthday, eight years after Queen Elizabeth II granted him a posthumous pardon.

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

It weighed 30 tons and had 18,000 vacuum tubes; six women wrote its programs by wiring plugboards.

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

It was finished at the University of Pennsylvania just after the war it was built for had ended.

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

Plus 7,200 diodes, 6,000 relays and 70,000 resistors, all in a machine 100 feet long.

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

The moth is taped into the logbook; 'bug' for a fault was already engineering slang in Edison's day.

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

She held the rank of rear admiral, was nicknamed Grandma COBOL, and has a guided-missile destroyer named after her.

Grace Hopper finished her A-0 System in 1952. What kind of program was it, the first of its kind?

She called it a compiler though it worked more like a linker; the idea that code could write code was radical.

Bardeen and Brattain first demonstrated the transistor in 1947 using which element?

They shared the 1956 Nobel Prize in Physics with William Shockley; silicon took over later.

What is the most numerously manufactured artificial object in history?

More than 13 sextillion had been made by 2018; Atalla and Kahng demonstrated the first one at Bell Labs in 1960.

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

Gordon Moore first said every year in 1965 and revised it to two in 1975; it is an observation, not a physical law.

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

He and Robert Noyce left Fairchild to start it in 1968; Moore himself said the exponential 'can't continue forever'.

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

The intended word was LOGIN; the full message went through about an hour later.

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

It replaced the Network Control Protocol; the ARPANET itself was decommissioned in 1990.

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

He picked it because it did not appear in usernames and already meant 'at'.

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.

On what date did CERN make the Web's protocol and code available royalty-free to the world?

The decision is widely credited with letting the Web beat rival systems like Gopher.

The Linux kernel was first released on 17 September 1991 by which Finnish student?

Its penguin mascot Tux was drawn by Larry Ewing, and it now runs all of the world's 500 fastest supercomputers.

As of 2017, how many of the world's 500 fastest supercomputers ran Linux?

Android, the dominant smartphone system, is also built on the Linux kernel.

The programming language created by Guido van Rossum in 1991 is named after what?

Guido van Rossum released version 0.9.0 in 1991 and was the community's 'benevolent dictator for life' until 2018.

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

Get the whitespace wrong and the program simply will not run.

Java was originally called Oak. Why?

James Gosling designed it at Sun Microsystems and it shipped in May 1995 with the promise 'write once, run anywhere'.

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

Java programs compile to bytecode that runs on the Java virtual machine rather than directly on the chip.

Which British computer scientist developed Quicksort in 1959?

He needed it to sort words for a machine-translation project in Moscow; it is a divide-and-conquer method built around a pivot.

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

The average case is O(n log n), and the worst case is rare enough that it stays faster than merge sort on random data.

P versus NP asks: if an answer can be checked quickly, can the problem also be what?

Stephen Cook stated it precisely in 1971; a survey in 2018 found 99 percent of experts believe P is not equal to NP.

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

It is one of the seven Millennium Prize Problems; only the Poincaré conjecture has been solved so far.

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

Rivest, Shamir and Adleman published it in 1977; Clifford Cocks at GCHQ had secretly invented the equivalent in 1973.

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

His work stayed classified until 1997, so the Americans got the name and the Nobel-adjacent fame.

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

It won 3.5 to 2.5 after losing the 1996 match, evaluating 200 million positions a second.

How many chess positions per second could Deep Blue evaluate?

It was a customised IBM RS/6000 SP designed by Feng-hsiung Hsu.

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

He called it the imitation game; the annual award named after him is computing's closest thing to a Nobel Prize.

The Year 2000 problem arose because many programs stored years as how many digits?

1985 was stored as 85, so 2000 looked like 1900; the fix is thought to have cost more than $300 billion worldwide.

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

The count of seconds since 1970 overflows on 19 January 2038; 64-bit systems push the problem out by 292 billion years.

Which of these is a four-bit unit of data?

Two of them make an eight-bit byte, which is why one hexadecimal digit maps neatly onto each.

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

That is 0 through 255, which is why old colour palettes and IP address fields stop at 255.

A kibibyte, defined by the IEC in 1998, is how many bytes?

The kilobyte was officially reset to 1,000 at the same time, though almost nobody says kibibyte out loud.

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

The Mark I was an electromechanical monster 51 feet long, built with IBM and installed at Harvard in 1944.

Who independently stated the P versus NP problem in 1973, two years after Stephen Cook?

The Cook-Levin theorem that bears both their names shows Boolean satisfiability is NP-complete.

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

An inquest ruled suicide; a half-eaten apple was found beside him but was never tested.

Which two Bell Labs engineers proposed the silicon MOS transistor in 1959 and demonstrated it in 1960?

Their MOSFET made integrated circuits practical and is the device Moore's law counts.