The Adv OS class is a fun class, particularly, coz of the professor. Partly coz the prof looks like my elderly uncle and partly coz he talks like one too.. :)..
Anyways, when we reached the "von neumann architecture" part of the lesson today, the prof said, "Most of the current architectures are based on this basic architecture presented by von neumann. Although extensive research is being done, nobody has been able to come up with a better alterative than this one". He further went on to explain about artificial intelligence and said that one of the most amazing architectures till date has been that of a "human mind"...
"Does the human brain work sequentially?? Is it like all of you think or do one thing at any given time??" he asked. "No sir, its all concurrent", some of us mumbled. What he went on to say was so profound that I felt I had to "document" it for future reference (in SE jargon). So here it goes:
(note that this is my understanding of what he said and probably not his exact words)
The human brain or mind is a complex entity. No one as yet has figured out how it exactly works. No one has yet succeeded in building a system that works like "THE MIND".
Though we cannot calculate as fast as a computer, we cannot think as logically and methodically as an ALU either. If all of us were ALUs then there would be no difference of opinions or disagreements as we all would get the same input and would produce the same output (as ALUs). However as a counter arguement, each of us perceive our inputs in a different way. If thats the case, then we cannot be ALUs as the ALU has no in-built intelligence for differential analysis of the inputs. Thus we are not ALUs.. In fact we dont know what we exactly are.. :D.. To put it simply, We are different..
Think about how our vision works. We have a pair of lenses that produce an inverted image at the back of our eyes on the retina. The pair help us to percieve the depth in what we see ("one for mono, two for stereo" to quote prof). The sensory nerves carry this information to the brain where a consistent 3D image is constructed in real time (just imagine the response time requirement of this system). There is no other existing image processing system that can construct and percieve 3D images at speeds comparable to that of the human vision...
Think about face recognition. A fleeting view of someone sticks on for an eternity but sometimes we forget faces within a fraction of a second (Out of sight is Out of mind.. :D).. However, it doesnt take long for us to recognise a familiar face in a crowd or recall the context in which we saw them. The complexity of memory management, pattern recognition, database search & retrival and contextual inference involved in such action is simply unimaginable...
And so it holds for the Audtion system (perception of sound) too. A piece of membrane, when struck with sound waves collected by the auricle, amplifies these waves to the inner ear and these are in turn converted to nerve impulses by the mechanoreceptors (or hair) in the cochlea. The Digital Signal Processing system (or is it Analog?? :D) in the brain then converts to impulses into meaningful sounds, all in realtime. (Just a thought.. what are those DSP students in our class trying to do?? :D).
On the same lines, I recall what my Distributed Algos prof had once said - "Can we build a system like the human heart, that runs right from the time we are born to the till the day we cease to exist (thats about 60 yrs on an average), working non-stop while consuming minimal amount of resources and not failing even once.. :)..". Think about the robustness and fault tolerance of such a system that seems to work under every ambient condition possible.. :D..
In conclusion of this huge post, I'd say it seems as though we humans have been built based on "some" profound and enigmatic architectural design that remains incomprehendable and irreproducible till date... Does that make us "unchallenged-as-yet" as well??.. I wonder... :)..
