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Reimagining of Schrodinger's Cat Breaks Quantum Mechanics -- and Stumps Physicists (nature.com)
In a multi-'cat' experiment, the textbook interpretation of quantum theory seems to lead to contradictory pictures of reality, physicists claim. New submitter Lanodonal shares a report: In the world's most famous thought experiment, physicist Erwin Schrodinger described how a cat in a box could be in an uncertain predicament. The peculiar rules of quantum theory meant that it could be both dead and alive, until the box was opened and the cat's state measured. Now, two physicists have devised a modern version of the paradox by replacing the cat with a physicist doing experiments -- with shocking implications.
Quantum theory has a long history of thought experiments, and in most cases these are used to point to weaknesses in various interpretations of quantum mechanics. But the latest version, which involves multiple players, is unusual: it shows that if the standard interpretation of quantum mechanics is correct, then different experimenters can reach opposite conclusions about what the physicist in the box has measured. This means that quantum theory contradicts itself.
The conceptual experiment has been debated with gusto in physics circles for more than two years -- and has left most researchers stumped, even in a field accustomed to weird concepts. "I think this is a whole new level of weirdness," says Matthew Leifer, a theoretical physicist at Chapman University in Orange, California. The authors, Daniela Frauchiger and Renato Renner of the Swiss Federal Institute of Technology (ETH) in Zurich, posted their first version of the argument online in April 2016. The final paper [PDF] appears in Nature Communications on 18 September.
Quantum theory has a long history of thought experiments, and in most cases these are used to point to weaknesses in various interpretations of quantum mechanics. But the latest version, which involves multiple players, is unusual: it shows that if the standard interpretation of quantum mechanics is correct, then different experimenters can reach opposite conclusions about what the physicist in the box has measured. This means that quantum theory contradicts itself.
The conceptual experiment has been debated with gusto in physics circles for more than two years -- and has left most researchers stumped, even in a field accustomed to weird concepts. "I think this is a whole new level of weirdness," says Matthew Leifer, a theoretical physicist at Chapman University in Orange, California. The authors, Daniela Frauchiger and Renato Renner of the Swiss Federal Institute of Technology (ETH) in Zurich, posted their first version of the argument online in April 2016. The final paper [PDF] appears in Nature Communications on 18 September.
The whole point of Schrodinger's cat experiment was to show that trying to apply certain quantum physics theories to reality resulted in absurd results.
To him (and Einstein), it was obvious that the cat could not be both alive and dead, and therefore the people pushing the superposition theory were obviously wrong.
It's a shame that his thought experiment has been taken to mean the exact opposite of what he was originally talking about.
The whole point of the Schrodinger's cat thought experiment was that quantum physics can apply to large scale things like cats and people, indirectly, if you design a mechanism to make it so.
No, the whole point was to point out the absurdity of the Copenhagen interpretation. Unfortunately, most people tend to miss this part and think that Schrödinger espoused the point of view that he was actually arguing against.
"Conscious observer" has nothing to do with it. The Geiger counter rigged to the poison is the observer that collapses the wave state.
Socialism: a lie told by totalitarians and believed by fools.
And the Copenhagen interpretation is the new "Bohr atom model" - almost no one believes it this century
A 2011 survey of attendees of a conference on quantum physics would disagree with you, with 42% of the respondents (a plurality) listing the Copenhagen interpretation as their favorite interpretation of quantum mechanics.
Anyhow, measurement devices collapse the wave state, removing this sort of uncertainty at the point of measurement.
Sorry -- what's your definition of the Copenhagen interpretation? Because, to my understanding, wave function collapse on measurement *is* the Copenhagen interpretation: "Here's the quantum regime. Here's the classic regime. The result of a 'measurement' is always classical. -- How do you go from quantum to classical? It doesn't matter, it just does. We have well defined procedures to extract the empirical (classical) measurement results from a given quantum result. Throw a black box over the 'how', then shut up and calculate."
You are correct.
And, by "measurement," we don't mean "humans looking at it."
The "measurement problem" was settled long ago in that there are a shit load of "measuring devices."
When a quantum interacts with anything , that's a measurement.
It little behooves the best of us to comment on the rest of us.