Einstein’s brilliant mistake: Entangled states

Albert Einstein’s greatest contribution was a 1935 paper that he co-authored with his young colleagues. Through his theory of the photoelectric effect, Albert Einstein launched quantum mechanics. He remained disturbed by the philosophical implication for men though. Here we will be talking about the brilliant mistake of Einstein in a more elaborated way:-

Entangled states

The EPR paper that Albert Einstein launched has become the center of attraction for the new understanding of quantum physics. A strange phenomenon was described that came to be known as entangled states. 

Paper of Albert Einstein 

In a source, a pair of particles with their own measurable properties are spitted out having two absolute results of their own and the probability is the same. For instance, we can assume ‘1’ and ‘0’ to be the result if the first property and ‘a’ and ‘b’ can be assumed to be the result of the second property. The result for the measurement of the same property and of the same particle will give the same result. 

Strange Phenomenon

Not only the state of the individual particle is unsure until and unless it is measured but also the measurement of that particular particle decides the state of that particular particle. And not just that, the measurements affect each other as well. 

For instance, if a particle when measured is in state 1, perform the second type of measurement: the discovery will be that one will get either ‘a’ or ‘b’.  But, the catch here is that if the first measurement is repeated, one will get ‘0’ despite the fact that the particle has been measured already at ‘1’. This proves that, if the properties for measuring are switched, the result will not be uniform. 

When both the particles are analyzed they will give random results but when they are compared, it is discovered that they are aptly correlated.  For instance, when both the particles are measured at 0, the relationship will hold and be steady.  This means that the states of these two particles are entangled.

Defying Einstein Theory of Relativity

The performance of the entanglement doesn’t obey the theory of relativity; the reason being that nothing ought to limit the distance between particles. The measurement results in the value implying that the first particle sends some sort of signal to the other at the rate of 13 million times the speed of light. This according to relativity is not possible. 


Einstein considered it as ‘spooky action at distance’ not until John Bell came to the rescue. Bell established that the state being undetermined until measured has different limits. He predicted measurement results that are mixed and are impossible In a predetermined scenario. Following his lead, other physicist tested EPR argument as well. The thing that they found is that ‘quantum mechanics is correct’. Precisely, the correlations between the entangled particles that are undetermined are legit and could not be further explained by any deeper variable.  Thus the EPR paper by Albert Einstein was wrong. 

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