Making An Observation Without Making An Observation: “Seeing” Knowledge Embedded In The Physical World With One’s Own Eyes

In electron shelving, one kind of quantum jump in which an electron in an atom moves in a discontinuous fashion to another energy level, a person can "see" knowledge that a weak transition (which is very slow) has occurred since it is proven that a strong transition (which is very fast) has not occurred in the time in which the strong transition can occur. This is a null measurement. There is no physical detection of the photon in the weak transition. There is only the logical deduction that the weak transition occurred since one cannot detect the photon in the strong transition, the only other possible transition. Looking at the interruption in the fluorescence that occurs in the strong transition, a “dark” interval, is "seeing" the knowledge resulting from the logical deduction. The significance of a null measurement in leading to the conclusion that one can "see" the knowledge resulting from a logical deduction is discussed. The null measurement in the weak transition is one form of Einstein’s spooky action where something not physical occurring in the possible strong transition leads to the occurrence of the weak transition. (2021 April Meeting of the American Physical Society, https://meetings.aps.org/Meeting/APR21/Session/KP01.48)

Dynamical symmetrization of the state of identical particles

We propose a dynamical model for state symmetrization of two identical particles produced in spacelike-separated events by independent sources. We adopt the hypothesis that the pair of non-interacting particles can initially be described by a tensor product state since they are in principle distinguishable due to their spacelike separation. As the particles approach each other, a quantum jump takes place upon particle collision, which erases their distinguishability and projects the two-particle state onto an appropriately (anti-)symmetrized state. The probability density of the collision times can be estimated quasi-classically using the Wigner functions of the particles’ wavepackets, or derived from fully quantum mechanical considerations using an appropriately adapted time-of-arrival operator. Moreover, the state symmetrization can be formally regarded as a consequence of the spontaneous measurement of the collision time. We show that symmetric measurements performed on identical particles can in principle discriminate between the product and symmetrized states. Our model and its conclusions can be tested experimentally.

Urban–Rural Dichotomy in Planning: Review of Legal Framework in Four States of India

Current urbanisation trends in India show a quantum jump in number of ‘census towns’, which are not statutorily declared as urban areas, but have acquired all characteristics of urban settlements. Sizeable number of such census towns are not located near any Class 1 city. Lack of proper and timely planning has led to unplanned growth of these settlements. This article is based on a review of planning legislations, institutional framework and planning process of four states in India. The present article analyses the scope and limitations of the planning process adopted in the rapidly urbanising rural areas of these states. The findings reveal that states are still following a conventional approach to planning that treats ‘urban’ and ‘rural’ as separate categories and highlights the need for adopting an integrated territorial approach to planning of settlements.