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Quantum mechanics



      I was reading "Essentials of Statistical Thermodynamics" by Nash today. Several things that he said made me realize a lot of truths about Stat ThermoDyn. He starts by saying that thermodynamics teaches us what happens and how much of it happens, but it does not tell us why it happens. Most such textbooks would probably say the same thing, and then proceed to drown us in jargon and all manner of equations. My favorite part is when these oh-so-smart guys shove my ignorance in my face by sating things like "It is trivial to extrapolate from this 3 term equation to a 30 term equation". And I am left wondering what the hell happened. Needless to say, from that point onwards I am too annoyed to make sense of anything. So Nash takes us through the subject with minimal assumptions and the Boltzmann distribution almost seems like a natural extension of basic probability which actually it is. So, reading his book got me thinking about a lot of other things and I ended up with my interpretation of the interpretations of Quantum mechanics. Physicists beware! This might induce a strong fit of laughter so read it while firmly placed on a chair or better still sit on the ground.

      The system we will consider is a coin toss. Heads is one quantum state and tails is another.

      Copenhagen Interpretation : The coin is flipped into a bottomless pit. A platform is extended by the user at a random point into the pit. So depending on when and how the platform was extended, we will see one of either heads or tails. Until that point, the coin is in an indeterminate state.

     Many worlds interpretation : The coin is flipped and it falls to the ground. At that instant two universes are created one in which the coin lands on heads and the other in which it lands as tails. Needless to say this is stupid.

      Bohmian interpretation : Coin is flipped and it falls to the ground. Owing to our ignorance about the air density and gravitation of the room etc, we cannot determine exactly whether it will be heads or tails. But, the important thing is, if we knew all these hidden variables, we can determine heads or tails deterministically.

     Von Neumann interpretation : Coin is flipped and the flipper watches it fall down. Depending on the flipper's choice made in hi/her mind, the coin will either appear as heads or tails !!

     Those are the ones I am aware of. This leads me to another problem that has puzzled me since my school days. We make so many assumptions in deriving equations w.r.t any measurement. For example, Stirling's approximation is used heavily in any derivation of Boltzmann statistics. Then, the terms cancel out and get modified etc. What if we measure these values the correct way ? Would the laws still be valid ? I am sure they would be, but I have this nagging doubt about the whole thing. The closest someone comes to explain it is Resnick and Halliday's Physics textbook. While discussing gravitation, in a boxed feature, he examines how we know the exponent is 2.0 in the denominator of the gravitational law. And suggests that experiments suggest it is 2.0 +/- some 10-6 or something which is within experimental error. So based on this, I will explain Krishnadev interpretation.

      Krishnadev interpretation : Coin is flipped with a certain force. Due to inaccuracies in theories dealing with the entire universe, it gives a net random error in calculation of the said force, its effect on the coin, the coin's efect on the surroundings and etc etc which makes the outcome appear random. Believe me, it is not actually random !!!

Comments

Smita said…
one of the best till now....
LOL

Keep them coming
August 22, 2011 at 4:25:00 PM GMT+5:30
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