Jun 15, GianCarlo Ghirardi, former professor of theoretical physics and then emeritus at the physics department of our university, passed away on 1st. GianCarlo Ghirardi. Angelo Bassi and Tullio Weber. University of Trieste, Trieste, Italy. Detlef Dürr. Ludwig-Maximilians University, Munich, Germany. PDF Full. Jun 4, The ICTP community is mourning the sudden passing of long-time colleague GianCarlo Ghirardi. Professor Ghirardi was associated with ICTP.

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In ghirardu information physics solution to the problem of measurementthe timing and location of the Heisenberg “cut” are identified with the interaction between quantum system and classical apparatus that leaves the apparatus in an irreversible stable state providing information to the observer.

Peculiar ‘measurement’ results for angular momenta, energies, and so on, emerge as pointer positions in appropriate experimental setups.

ICTP – In Memoriam

Giancarlo Ghirardi 28 October — 1 June was an Italian physicist and emeritus professor of theoretical physics at the University of Trieste. To be rigorous we would have to do what we did at first, namely, add points that would refer to all the other degrees of freedom of a system as complex as this.

He then moved to Trieste in August where he assumed a full-time teaching position with the theoretical physics gianvarlo at the University of Trieste. So there must be some kind of ‘collapse’ going on in addition, to enforce macroscopic narrowness. Ghirardi—Rimini—Weber theory Quantum mechanics foundations.

But in macroscopic systems, as a consequence of the prescribed equationspointers very rapidly point, and cats are very quickly killed or spared. Then came the Born interpretation. We can ask ourselves then: It gives the density in a multidimensional configuration space! This simple observation tells us that at a certain point between the level of microscopic events that giancar,o doubtlessly governed by the principle of superposition microsystems show the effects of interference and the level of the perception on the part of a conscious observer, the linearity has to be violated.


Particles are not attributed angular momenta, energies, etc. Why would that interpretation not have to face the embarrassing occurrence ghiraedi superpositions of states that are distinguishable at the macroscopic level?

GianCarlo Ghirardi – Citazioni di Google Scholar

Retrieved from ” https: When we watch the film, our own perceptive apparatus enters the picture. For simplicity we will suppose, with von Neumann, that the photon passes through the apparatus without changing its state. Renew your membership Member directory.

Some qualifications are in order. John Bell called this movable boundary a “shifty split,” and illustrated it with a sketch below. The orthodox approaches, whether the authors think they have made derivations or assumptions, are just fine FAPP — when used with the good taste and discretion picked up from exposure to good examples.

The treatment is oversimplified.

Giancarlo Ghirardi

We then can ask ourselves: As a consequence no prediction of standard quantum formalism for microsystems is changed in any appreciable way.

The problem is traditionally approached with reference to what is technically known as von Neumann ‘s ideal measurement process, named from the scientist who first formulated it in precise terms. This is not spelled out very explicitly. GianCarlo Ghirardi on Measurement In his elegantly written and nicely illustrated book, Sneaking a Look at God’s CardsGhirardi starts his discussion of the measurement problem by noting that the principle of superposition of states means that some observables lack a precise expectation value, so we can speak only of the probability of outcomes.


Schematic representation of the effect obtained by activating an ideal measuring apparatus by states having the precise polarizations that the apparatus is set up to reveal.

In Memoriam

The dynamics is not very precisely formulated either. It is perhaps the most complete collection of ‘scientific’ banknotes in the world. But this does not change in the least the objective “given” that such a superposition must be considered present whenever it is assumed that we have at our disposal an apparatus that reliably allows the identification of vertical or horizontal polarization of a photon, and that the interaction between the measured system and the measuring apparatus is a process that obeys the general laws of the theory.

We now prepare an initial state that is a linear combination of the two initial states considered above: Then the x s must not be confined to some vague macroscopic scale, but must extend to all scales.

So the wavefunction must be narrow as regards macroscopic variables. Like any physical theory, even quantum mechanics will have a limited field of application.