## Honoring Alan Turing, "Father of Computer Science" 230

alphadogg writes

*"Google's Vint Cerf and others are spearheading celebrations in Silicon Valley and the UK this month to celebrate the 100th anniversary of Alan Turing's birth. 'The man challenged everyone's thinking,' says Vint Cerf, Google's chief Internet evangelist, in an interview with Network World. 'He was so early in the history of computing, and yet so incredibly visionary about it.' Cerf — who is president-elect of the Association for Computing Machinery and general chair of that organization's effort to celebrate the upcoming 100th anniversary of Turing's birth on June 23 — says that it's tough to overstate the importance of Turing's role in shaping the world of modern computing. Turing's accomplishments included his breakthrough Turing machine, cracking German military codes during WWII and designing a digital multiplier called the Automated Computing Machine."*
## Google doodle finally (Score:4, Informative)

## Not just computers (Score:5, Informative)

Turing didn't just help with practical computers. A lot of his ideas mattered in many other fields. For example, his idea of the Turing machine http://en.wikipedia.org/wiki/Turing_machine [wikipedia.org] and related work was vital to a lot of other fields such as the rise of theoretical computer science, and even as far as the study of equations with integer solutions (called Diophantine equations) in the form of Hilbert's Tenth Problem http://en.wikipedia.org/wiki/Hilbert's_tenth_problem [wikipedia.org].

Essentially, Hilbert asked whether there was a general algorithm to determine whether a given equation in integer variables had a solution. Even for individual equations figuring this out can be very difficult. For example it was known even in ancient times that x^2+y^2=z^2 had infinitely many integer solutions, but it took Fermat to show that x^4+y^4=z^4 did not. It turned out that there is no general way of answering these sorts of questions. The problem was solved by lot of people, especially Julia Robinson, Martin Davis, , Hilary Putnam, and ultimately finished off by Yuri Matiyasevich. The solution was to show that one can actually model an arbitrary Turing machine as a system of Diophantine equations, where the machine halting is equivalent to the Diophantine equations having a solution. Thus, if one can solve that one can answer whether any given Turing machine can halt, which Turing showed could not be done in general, using a clever trick- this is known as the Halting theorem http://en.wikipedia.org/wiki/Halting_problem [wikipedia.org]. Curiously, the equivalent problem over the rationals is still open, and is turning out to be connected to deep issues in topology and the theory of elliptic curves. So Turing's ideas and thoughts are still pushing us forward and making us ask new questions.

## What about,,, (Score:5, Informative)

Charles Babbage [wikipedia.org] & Ada Lovelace [wikipedia.org]?

For you young whipper-snappers:

## Not Turing. von Neumann. (Score:5, Informative)

Von Neumann was much more influential than Turing. Not only did von Neumann do brilliant work in multiple areas of mathematics, he invented modern computer architecture. [stanford.edu] Babbage's design was more like a Jacquard loom card reader coupled to a calculator. Turing's theoretical machine had to roll a long tape back and forth, and the cryptographic machines were essentially hard-wired or plugboard-programmed. Those machines are closer in concept to Hollerith/IBM tabulators of the 1920s to 1950s.

Von Neumann got computer architecture right. He saw that the right answer was RAM, with programs and data in the same memory:

The device requires a considerable memory. While it appeared that various parts of this memory have to perform functions which differ somewhat in their nature and considerably in their purpose, it is nevertheless tempting to treat the entire memory as one organ, and to have its parts even as interchangeable as possible for the various functions enumerated above."He also figured out that 1) everything inside the machine should be binary, not decimal, 2) memory sizes should be a power of two, 3) about 2^18 bits of RAM were needed to get any useful work done, 4) delay-line memory would work in the short term, but "iconoscope" memory (see Williams tube [wikipedia.org]), which is random access, would be better, and 5) what a reasonable instruction set should look like.

## Re:Father of the computer science ? (Score:3, Informative)

Keep in mind that "computer science" is not the science of building computers

Keep in mind that Lady Ada Lovelace didn't take any part in the "building computer" phase

The role of Lady Lovelace is in the "Programming"

Do read up Lady Ada Lovelace when you have the time