Einstein vs Quantum Mechanics Why did Albert Einstein have so much difficulty accepting Quantum Mechanics ?
Albert Einstein one of the most famous physicist in the world and very much popular for mass-energy equivalence that is E = mc2
Then Why did Albert Einstein have so much difficulty accepting Quantum Mechanics? Quantum Mechanics is very vast subject to study and is very difficult to understand but in short we can conclude that Quantum Mechanics implies that a particle such as ELECTRON can pass through TWO HOLES AT ONE TIME
His study of quantum mechanics’ “spookiness” led to a slew of new developments, including quantum teleportation and quantum cryptography, but he wasn’t entirely persuaded by the theory — and the story behind that is just as interesting as the theory itself. Quantum mechanics is a strange science. It means that a particle, such as an electron, may simultaneously pass through two holes.
More famously, German physicist Erwin Schrödinger’s equations demonstrated that a cat could end up in a strange quantum state where it was neither alive nor dead. None of this drew Einstein’s attention. He was convinced that quantum mechanics was right, but he was desperate to find a way to “complete” the theory so that it made sense.
Most quantum physicists at the time followed the “shut up and measure” philosophy: get on with the job and don’t think about metaphysical questions — just get the results.
Heisenberg’s Uncertainty Principle, which states, among other things, that it is impossible to determine both the location and the momentum of a particle simultaneously to arbitrary precision, was used against Einstein by his critics. When anyone takes a measurement of a particle’s location, the particle is disturbed, and its momentum shifts. How can those two items be described together if they can’t be measured at the same time?
Opponents assumed Einstein didn’t grasp quantum mechanics, but he understood the issue was more serious. Then, oh my goodness, Eureka! Einstein came up with a way to describe quantum mechanics’ problems in 1935. He’d make a compelling case for how position could be determined without disrupting the particle! Einstein (with American physicists Boris Podolsky and Nathan Rosen) discovered quantum entanglement.
Quantum entanglement between two particles means that the quantum wave function representing them can’t be mathematically factored into two bits, one for each particle. This has significant ramifications. Entanglement occurs when two particles become specially bound in a “spooky” way that was ultimately revealed by Einstein’s claims and subsequent experiments.
Einstein, Podolsky, and Rosen (known as EPR) realised that quantum mechanics predicted entangled states, in which two particles’ locations and momenta are completely correlated no matter how far apart they are. That was significant to Einstein, who assumed that whatever was done to the first particle would not cause any immediate disruption to the second particle. This was dubbed “no-spooky-action-at-a-distance” by him.
Assume that a girl named Alice measures the position of the first particle while a boy named Bob measures the position of the second particle at the same time. Because of the perfect correlation, Alice knows the outcome of Bob’s measurement as soon as she takes her own measurement. Her prediction for Einstein’s magical entangled states is dead on — no errors at all.
Then Einstein concluded that this could only happen because Bob’s particle had the exact location predicted by Alice. Nothing will shift at Bob’s position due to Alice’s calculation, which cannot affect the second particle. Since the measurements of Bob and Alice are separated by space, Einstein deduced that a hidden variable must exist to explain the precisely defined value of the position of the second particle measured by Bob.
Similarly, Alice can now predict Bob’s particle’s momentum with utter accuracy without disrupting it. Then, assuming no strange behaviour, Einstein stated that, regardless of Alice’s calculation, the momentum of Bob’s particle could be precisely determined. As a result, Bob’s particle has exact values for both position and momentum, which goes against the Heisenberg Uncertainty Principle.
The inconsistency between quantum mechanics as we know it and the assumption of “no-spooky-action-at-a-distance” was demonstrated by Einstein’s claim. Einstein believed that the easiest solution to the problem was to add hidden variables that were compatible with no spooky behaviour, completing quantum mechanics.
Of course, the most straightforward solution is that Einstein’s entanglement does not exist in nature. There have been suggestions that entanglement decays with the spatial separation of the particles, in which case quantum mechanics and spooky behavior will be incompatible. Einstein’s entanglement had to be confirmed experimentally.
Chien-Shiung Wu, also known as Madame Wu or the First Lady of Physics, from Columbia University was the first to demonstrate Einstein’s entanglement in the laboratory. She demonstrated an Einstein-type association between the polarization of two well-separated photons, which are light particles that are tiny and localized. Einstein was taken seriously by John Bell, a physicist at CERN, who decided to establish a hidden variable theory along the lines proposed by Einstein. He studied Madame Wu’s states, but when he looked closely at their forecasts for some minor adjustments in measurements, he discovered an unexpected result.
Finding such a hidden variable theory would be unlikely, according to quantum mechanics. For Einstein’s secret variables and quantum mechanics, experimental measurements will yield different results. This meant that either quantum mechanics was incorrect, or that any secret variable theory capable of completing quantum mechanics had to allow for “spooky-action-at-a-distance.”
In a nutshell, experimentalists John Clauser, Alain Aspect, Anton Zeilinger, Paul Kwiat, and colleagues tested Einstein’s hidden variable theories using the Bell proposal. So far, all evidence points to quantum mechanics. When two particles get entangled, it seems that whatever happens to one will immediately impact the other, even though the particles are separated!
Have experiments shattered Einstein’s hopes for a better theory? That’s not the case. Photons, not large particles like electrons or atoms, have been the subject of previous studies. They also don’t work for very large systems. As a result, I don’t believe Einstein would give up just yet. He believes that the rules for actual particles are different.
Australian scientists are experimenting with atoms and even miniature structures that have been cooled to the point where they have lost all thermal jittering in order to test Einstein’s and Bell’s theories. Who knows what they’ll come across? What about my contribution? After seeing scientists could amplify and detect the tiny quantum fluctuations of optical amplitudes when working with compressed states of light in the 1980s, I came up with a way to test for the original Einstein’s entanglement.
These are equivalent to “place” and “momentum” in quantum mechanics, and the experiment opened up a whole new way of evaluating Einstein’s entanglement. Experiments in a variety of environments have since verified this mesoscopic form of Einstein’s entanglement, bringing us closer to understanding Schrödinger’s cat.