Alive and Dead...part 2

Alright guys, i am back again after a couple of Lost episodes... I just realised I have been building and hyping the subject up without actually giving anything that can make you go oooooohhhh and aaaaahhhh...i shall not waste anymore of your time, but at this very last moment i shall repeat this---> QM unlike CM is very abstract and something we cant easily relate to, even though i wont be going into the related mathematics of it. QM does lack that intuitive appeal i mentioned before and will be anything but obvious. Ok? Lets start...
Since I am avoiding talking about atoms and electron states, the simplest eg i can think of is that of a simple coin toss. Now this can be heads or tails, which is pretty clear (and this is what CM will equivalently predict) but what QM says is that not only is head and tails possible but so is any "state" between head and tail!! "omggwtff??" you ask... very simple, if u say heads and tails are two possible things a coin toss can give you, the postulates of QM will prove that a state in the form of 0.6head and 0.4tail is also possible!! Note: this is not heads or tails...this is both heads AND tails at the same time!!! What thats just ridiculous?!!?That doesnt even make sense!! Well guess what... its actually possible!!
"Hmmm ok ok, i have known u for years nut and i believe what u just said, as ridiculous as it sounds.Now if these "superposition" (thats what they are called) is also possible, then how come we have never measured it?? surely its not possible that everyone over the course of 1000's of years making millions of measurement missed something so different" Good question!! This is where another postulate of QM kicks in. Lets see if we all agree what measurement is. A measurement in a way is like taking a really really long stick and poking the thing you wanna measure from a distance and see what reading you get. CM assumes that you making a measurement or taking this stick and poking the thing doesnt actually make a difference. A fairly sane assumption if you promise not to poke too hard or for too long. If this actually was true, then your question would be very valid and we should have seen this "superposition" states by now. But QM is more detailed and says you observing( ie measuring) actually does affect the system, infact it affects in a very big way. In such a big way, you actually destroy it!! YOU have caused the system to collapse!! (For those who are really interested, look for the phenomenon of wave collapse) Hmmm so if i destoyed it, will i always get zero as the answer you ask?? Not really, when i say the system collapsed, I meant it collapses to give you a certain set values. Am i sounding too out there?? Cool,I will get back to the coin toss example...what this last few lines means is, if the coin actual could be in heads AND tails (superposition) state,you trying to measure it will cause it to "collapse" and it will end up giving you heads or tails like CM!!
"Aaaahhh thats just highly convenient da nut!! U are effectively saying this "superposition" state exists but you cant show it to me because trying to show me will destroy everything!! yaaru kadhula poo suthare??" My thoughts exactly and ejjactly what i asked my prof but i didnt quite pose it that way!! lol Since i promised not too go into the deep maths of this, my best answer is to just trust me, its how it is, no matter how counter intuitive it sounds. (For those read more on wiki but have some questions, hit me on gtalk and i am up for a talk anytime!! :D ) Now lets stick with the whole coin analogy. QM says if we did the whole coin toss act a very large number of times and find out how many times heads turned up and how many times tails turned( in short there probabilities), you have mathematical thingamajings to back calculate exactly what superposition state it was in!! But I gave you this to indicate that while CM is "deterministic" ie you can say for sure that this what you have, QM is what we called "probabilistic" or everything is a probability!! Yep everything is a probability. It can have a very high probability or low probability but everything comes with a probability!! You dont say anything for sure!!
You can ask me "will you come to school today?"
CM answer: " i will!!" QM answer: "the probability of me coming to school is pretty high"
I think i have basically covered everything as simple as i can possibly can (ps: the truth is, it was put to me in an even simpler way but i am not as good as my prof). I am going to let you guys read over this a couple of times before it makes sense because it took me several days involving sleepless nights and banging my head on the wall kinda action before it started making sense. I will end my mindless rambling with one last post on the various weird things QM can actually predict..some of which is plain ridiculous (even by QM's standards) and some which actually turn out to be true...


Natesh
...trying to calculate the band structure...


PS: To those science students who have come across eigenvalues and the eigen equations, lemme continue a little bit more. The rest,I warn you, I have been raring to become technical and I shall do so here. The various values that system can collapse to is obtained by solving the corresponding eigenvalue equation when acted upon by the respective operators(dont ask...long story!!!)
Why these values?? the truth is we actually dont know!! YES!! A fundamental postulate in the most researched theory in physics and we dont know!!
Why does the system collapse? This was unexplained for a very long time till the theory of decoherence was proposed (a while back).I shall not even try and explain what this is because it gets very very messy and confusing!!