Skip to comments.Research team challenges the limits of famous quantum principle
Posted on 02/08/2014 4:04:33 PM PST by SunkenCiv
Almost a century ago, renowned quantum theorist Werner Heisenberg found fundamental limits on how well a quantum system can be prepared and measured, known as Heisenberg's uncertainty principle.
However, only the limit that pertains to the preparation of quantum systems has been quantified; the other two, relating to measurements, have long been a matter of debate, lacking a formal treatment.
These limits are: That it is impossible to jointly measure incompatible quantities, for instance, location and speed of a quantum object, with perfect accuracy; and that a measurement of one of these quantities necessarily disturbs the other.
Last year, UQ's Cyril Branciard proposed a new set of "uncertainty relations", for the joint measurement of incompatible quantities, which describe the minimal disturbance that will occur for a given measurement accuracy.
"Branciard's relations quantify how accurately we can measure," Mr Ringbauer said.
"Testing these relations, we are now able to show in the lab that we can actually reach this ultimate limit of accuracy," he said.
The study was published in January in the journal Physical Review Letters. A related work by Kaneda et al. in the same journal, has found similar results.
(Excerpt) Read more at phys.org ...
Heisenbergs uncertainty limits how sharp measurements can be performed on quantum systems. UQ researchers have now performed joint measurements of single photons, challenging the limits of quantum theory. Credit: Martin Ringbauer
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Posted on 1/22/2014 5:53:50 PM by ETL
Apparently, there is enough uncertainty in measuring the diameter of a proton , about a factor of five. Maybe we shouldn’t ooh and ahh so much. Especially when scientists, for whom I have great respect, weaponize their prestige to influence public perception and debate in untestable and even unknowable areas.
All scientific knowledge is nothing BUT defining statistical measurement thresholds.
In this case however, it seems that they’re addressing the issue of even HAVING a statistical measurement threshold, not refining it.
So I guess that counts as a discovery!
I would reply to this thread but the act of doing so would alter what I was going to say
OK, but how certain are they of their findings ??
My cat died.
Article speaks of “incompatible” quantities whereas Heisenberg spoke of conjugate quantities ( like position and momentum). ——?