Heisenberg Uncertainty Equation
Quantum World

How did Heisenberg get idea to deduce his astonishing ” Uncertainty Principle” ?

Twentieth century witnessed discovery of quantum mechanics . Neils Bohr , Heisenberg ,   Erwin Schrödinger and other scientists changed the view in fundamental understanding of universe forever….There is interesting tale with discovery of “Uncertainly Principle” .

Neils Bohr solved “colour mystery” of objects by way of strange hypothesis  which stated that energy of electrons in atoms could only assume in “quantized” values – certain specific value just as hypothesized by Planck and Albert Einstein for energy of quanta of light . These hypothesis define Bohr’s ‘ atomic model ‘ whose centenary was commemorated in  2013 . It defines spectra of all atoms and even to predict accurately spectra not yet observed . This is astonishing but simple .

Brilliant young scientists from all over the world gathered in Bohr’s institute of Copenhagen in order to solve the incomprehensible behavior in atomic model to construct a coherent theory .

The research was obscure , until a young German found a astonishing principle .

That German scientist was none other than W. Heisenberg . He made a simple but astonishing “uncertainty equation” to unlock the mystery that puzzled most of scientists even Bohr too .

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How did Heisenberg get idea ? What incident did take place with him ? 

Werner Heisenberg was twenty – five years old when he wrote the equation of quantum mechanics . The intuition came to him one night of 1925  in the park behind the Copenhagen Institute of Physics . The young Werner walked about pensively in the park . It was almost dark  there . There was an occasional street lamp , casting dim inlands of light here and there . The pools of light were separated by large expenses of darkness . All at once , Werner saw a figure pass by . Actually he did not see him pass : he saw him beneath the lamp , then disapper into dark the dark before reappearing beneath another lamp . And so on , from pool of light to pool of light , until he disappeared altogether in night .

W. Heisenberg thought that , ‘evidentely’ , the man did not appear or disapper :in his mind , he could easily reconstruct the man’s trajectory between one street lamp and other . After all , a man is substantial substance , big and heavy and heavy objects did not appear and vanish easily and simply .

Suddenly a idea came in his mind , he asked himself ” …….but what do we know about electrons? Why should small object such as electron do the same ? What if , effectively , electrons could vanish and reappear ? What if these were the mysterious quantum leaps which appeared to under lie the structure of the atomic spectra ? What if , between one interaction with something ,and another with something else , the electron could literally be nowhere ”

He further asked himself, ” what if always having a precise position is something which is acquired only if one is substantial enough – large and heavy like the man that passed by a little while ago , like a apparition in the dark and then , disapper into night ……?”

Thousand of questions started jumbling in his mind . Heisenberg came to his room with emotions and started to write a equation which changed our understanding in fundamental behavior of Nature .

What was his equation ? 

He wrote a equation of ” Uncertainty Principle “

Heisenberg Uncertainty RelationshipHeisenberg Uncertainty Equation

Symbols represent as

  • h-bar: “reduced Planck constant”
  • delta-x(∆x) : uncertainty in position of an object .
  • delta-p(∆p): uncertainty in momentum of given particle .
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