What is the relation of the human to the world and the things in it? Do the various forms of human interrogation of the world discover things, and with them, a world? That is, can we reduce Being to a separation of knower from what can be known, or of observer from what can be observed? This article interrogates the question of the human-world relation via an inter-disciplinary analysis. The “flesh of the world” phenomenology of Maurice Merleau-Ponty problematises the assumption that there is an inherent distinction between subject and object, by instead identifying the incarnation of both in the embodied act of perception. Merleau-Ponty’s philosophy of a reality-as-flesh will be employed alongside, and inside, physicist Niels Bohr’s demand that the constituent elements of physical reality emerge via the concurrent incarnation of the measurer and the measured during experimental procedures. Bohrian quantum physics is shown (in a manner which does not require the reader to be experienced in quantum theories) to evoke the co-manifestation of subject and object for which Merleau-Ponty argues. In blurring notions of observer and observed, an ontologically productive, rather than epistemologically interrogative, operation is identified. This is used to investigate the human-world relation, and to argue against the notion that this relation, as a condition for there being phenomena, separates knower from what can be known, or observer from what can be observed.
In general, it is difficult to evaluate measurement errors when the initial and final conditions of the measurement make it impossible to identify the correct value of the target observable. Ozawa proposed a solution based on the operator algebra of observables which has recently been used in experiments investigating the error-disturbance trade-off of quantum measurements. Importantly, this solution makes surprisingly detailed statements about the relations between measurement outcomes and the unknown target observable. In the present paper, we investigate this relation by performing a sequence of two measurements on the polarization of a photon, so that the first measurement commutes with the target observable and the second measurement is sensitive to a complementary observable. While the initial measurement can be evaluated using classical statistics, the second measurement introduces the effects of quantum correlations between the noncommuting physical properties. By varying the resolution of the initial measurement, we can change the relative contribution of the nonclassical correlations and identify their role in the evaluation of the quantum measurement. It is shown that the most striking deviation from classical expectations is obtained at the transition between weak and strong measurements, where the competition between different statistical effects results in measurement values well outside the range of possible eigenvalues.
The
W state, a canonical representative of multipartite quantum entanglement, plays a crucial role in quantum information science due to its robust entanglement properties. Quantum uncertainty relations, on the other hand, are a fundamental cornerstone of quantum mechanics. This paper introduces a novel approach to Identifying tripartite
W states by leveraging tripartite quantum uncertainty relations. By employing a specific set of non-commuting observables, we formulate an uncertainty-based criterion for identifying
W states and rigorously demonstrate its generality in distinguishing them from other tripartite entangled states, such as the Greenberger-Horne-Zeilinger state. Our approach bypasses the need for complete quantum state tomography, as it requires only the verification of a set of uncertainty inequalities for efficient
W-state identification. This work provides a new theoretical tool for identifying multipartite entangled states and underscores the significant role of quantum uncertainty relations in entanglement characterization.