Friday, January 08, 2010

Mind game

Was looking at a Forbes article on IBM's cat brain simulation supercomputer (which is a neuroscience modeling platform, simulating a brain with 1 billion neurons and 10 trillion synapses which is almost the equivalent of a cat's cortex). There is cynicism in the way IBM touted it, when we are really still far far away from understanding how that gooey mass called brain really functions before even trying to model it. Got sidetracked into a diversion on perception and intuition which led me into the famous probability problem dubbed the "Monty Hall Problem". The solution for this was so controversial at that time (early 90s) that a cognitive psychologist stated that no other statistical puzzle comes so close to fooling all the people all the time and even Nobel prize winners systematically gave the wrong answer and argued against the right one.

The problem goes as follows.
Suppose you're on a game show, and you're given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1, and the host, who knows what's behind the doors, opens another door, say No. 3, which he knows has a goat. He then says to you, "Do you want to pick door No. 2?" Is it to your advantage to switch your choice?
and the same in a dis-ambiguated version to fix assumptions is as follows.
Suppose you’re on a game show and you’re given the choice of three doors. Behind one door is a car; behind the others, goats. The car and the goats were placed randomly behind the doors before the show. The rules of the game show are as follows: After you have chosen a door, the door remains closed for the time being. The game show host, Monty Hall, who knows what is behind the doors, now has to open one of the two remaining doors, and the door he opens must have a goat behind it. If both remaining doors have goats behind them, he chooses one randomly. After Monty Hall opens a door with a goat, he will ask you to decide whether you want to stay with your first choice or to switch to the last remaining door. Imagine that you chose Door 1 and the host opens Door 3, which has a goat. He then asks you “Do you want to switch to Door Number 2?” Is it to your advantage to change your choice?
If you have not come across this puzzle, try it. What would have been your answer? (No, it doesn't really matter, because there is an equal chance (or) Yes, I'll switch, what the heck (or) Leave me alone, my brain hurts) The solution has been discussed umpteen times, the problem statement reworded, variant behaviors discussed at length, proof in multiple forms, but this problem at times still confuses me because it is counter-intuitive to what we feel, think and assume about the problem. Probability and its conditionalities. Hmmm... (Somehow this problem reminds me of how Surya makes a scapegoat of Laila in glib talk + gambling in the Tamil movie Pithamagan :-))

Another interesting aspect of math theory is paradoxes. One of the famous ones is the liar paradox.
Epimenides was a Cretan who made one immortal statement: "All Cretans are liars."
How do you perceive the above statement? For me, it is like a hung process in Unix. :-)

And as regards perceptions and illusions, what else, but M. C. Escher's pictures for the visual paradoxes? Reality turned on its head with clever proportions. What an artist!!!


Waterfall

Copyright M. C. Escher

Official M. C. Escher website - http://www.mcescher.com

All copyrights acknowledged


All this reminds me of school/college days when we used to prove 0=1, 1=2 etc for fun using seemingly correct Algebraic formulations or differentiation rules.

Wish if only all Math were simple and as interesting without the tons of seemingly dry and drab theory that accompany the derivations...

Have a wonderful weekend.

Source acknowledgement: Wikipedia, Forbes. All copyrights acknowledged.

9 comments:

zeno said...

கெளம்பிட்டார்யா கெளம்பிட்டார்
Was ever wondering and in fact waiting when you will write posts like this, showing your true colors :)

RamMmm said...

இதை Technical postன்னு சொன்னா, அது அதுக்கே இழுக்கு. :-) Unix hung process is just a metaphor. You can solve and hang-up the paradox by kill -9 -1 <PID of Paradox>

Ha Ha Ha

Srivats said...

//Was looking at a Forbes article on IBM's cat brain simulation supercomputer (which is a neuroscience modeling platform, simulating a brain with 1 billion neurons and 10 trillion synapses which is almost the equivalent of a cat's cortex//

Edhey partha udaney escape aagi erukkanum...


erundhalum pona pogudhunnu padichen time romba nalla pass achu ;)

RamMmm said...

Srivats, nallaavey ottureenga, joining with zeno? :-)

yaenga, ungalukkaaga, time-pass panna puzzle, illusion padam ellaam poattu kaamichchirukkaen, "escape"nnu sollareenga? ;-) ;-) ;-)

Thought of putting Laila's picture (since she is referred to in the post), but that goes against the basic tenet of the post. :-)

gils said...

//Thought of putting Laila's picture (since she is referred to in the post), but that goes against the basic tenet of the post. :-)//

motha postum modha line patha udanaye ess :D kamentla intha linea paathutu again went back to see wats it abt :D laila padam potrukalam :(

chennai girl said...

Enakku intha postla purinjathu, antha illusion picture - waterfall apparam algebra , differenctiation ellam engeyo kelvi patta maathiri irukku avvalavuthaaan. Ithukkagathaan intha science pakkame naan pogala...

RamMmm said...

@gils - One fine day, I shall post, a picture of Laila or whomsoever with a deep technical post. :-) Till then, you can escape. :-) :-)

@chennai girl - How can you ignore probability theory, even in your stream (commerce, I presume)? evvalavu perisaa simple puzzle post panniyirundhaen? :-)

@gils, @Srivats, @zeno - naan thappu pannittaen. I should have reworded the puzzle as 'Shriya is behind one door and two donkeys behind the other doors' and then asked you to select a door and run that problem at you. :-) :-) :-) Escapum aaga maateenga, puzzleai neenga poattaa maadhiriyum aachchu. :-D

chennai girl said...

Probability i left in choice..three coins , 5 balls ,samples...it gave me creeps - naangellam average thaan..

RamMmm said...

Ha Ha Ha. Ennamo pohnga!!! :)