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The notion of time is given a different footing in Quantum Mechanics and General Relativity, treated as a parameter in the former and being an observer dependent property in the later. From a operational point of view time is simply the…

Quantum Physics · Physics 2017-05-24 Kiran Khosla , Natacha Altamirano

The recently introduced concept of an "ideal quantum clock" (IQC) is extended. Especially it is shown that the time operator of an IQC is canonically conjugated to the Hamiltonian of the IQC in a certain pre-Hilbert space. Further it is…

Quantum Physics · Physics 2015-11-10 Walter Gessner

In earlier papers we showed unpredictability beyond quantum uncertainty in atomic clocks, ensuing from a proven gap between given evidence and explanations of that evidence. Here we reconceive a clock, not as an isolated entity, but as…

Quantum Physics · Physics 2015-04-17 F. Hadi Madjid , John M. Myers

In contemporary physics space and time are intertwined entities so that kinematical and dynamical quantities are expressed in the four-dimensional space-time. This formulation seems to contradict our every-day experience and perception…

General Physics · Physics 2023-05-23 Orfeu Bertolami

Physics is a model of nature able to both describe and predict the results of measurements made with respect to reference systems. These reference systems, in turn, are themselves physical and thus subject to the laws of physics. The…

Quantum Physics · Physics 2025-09-05 Henrique A. R. Knopki , Renato M. Angelo

Quantum Theory, similar to Relativity Theory, requires a new concept of space-time, imposed by a universal constant. While velocity of light $c$ not being infinite calls for a redefinition of space-time on large and cosmological scales,…

History and Philosophy of Physics · Physics 2021-04-21 Herbert Capellmann

The description of the universe evolving in time according to general relativity is given in comparison with the quantum description of the same universe in terms of semiclassical wave functions. The spacetime geometry is determined by the…

General Relativity and Quantum Cosmology · Physics 2015-12-09 V. E. Kuzmichev , V. V. Kuzmichev

In the field theories with twistor structure particles can be identified with (spacially bounded) caustics of null geodesic congruences defined by the twistor field. As a realization, we consider the ``algebrodynamical'' approach based on…

High Energy Physics - Theory · Physics 2007-05-23 Vladimir V. Kassandrov

Possible theoretical frameworks for measurement of (arrival) time in the nonrelativistic quantum mechanics are reviewed. It is argued that the ambiguity between indirect measurements by a suitably introduced time operator and direct…

Quantum Physics · Physics 2007-05-23 Piret Kuusk , Madis Koiv

Despite the obvious utility of the concept, it has often been argued that time does not exist. I take the opposite perspective: let's imagine that time does exist, and the universe is described by a quantum state obeying ordinary…

General Relativity and Quantum Cosmology · Physics 2008-11-25 Sean M. Carroll

Wavepackets in quantum mechanics spread and the Universe in cosmology expands. We discuss a formalism where the two effects can be unified. The basic assumption is that the Universe is determined by a unitarily evolving wavepacket defined…

General Relativity and Quantum Cosmology · Physics 2016-04-22 Marek Czachor , Andrzej Posiewnik

The space-time geometry is considered to be a physical geometry, i.e. a geometry described completely by the world function. All geometrical concepts and geometric objects are taken from the proper Euclidean geometry. They are expressed via…

General Physics · Physics 2007-05-23 Yuri A. Rylov

We study longstanding problem of cosmological clock in the context of Brans-Dicke theory of gravitation. We present the Hamiltonian formulation of the theory for a class of spatially homogenous cosmological models. Then, we show that…

General Relativity and Quantum Cosmology · Physics 2011-06-09 Hossein Farajollahi , Mehrdad Farhoudi , Hossein Shojaie

We show that finite physical clocks always have well-behaved signals, namely that every waiting-time distribution generated by a physical process on a system of finite size is guaranteed to be bounded by a decay envelope. Following this…

Quantum Physics · Physics 2024-06-21 Nuriya Nurgalieva , Ralph Silva , Renato Renner

We develop a new model for the Universe based on two key assumptions: first, the inertial energy of the Universe is a constant, and second, the total energy of a particle, the inertial plus the gravitational potential energy produced by the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Hossein Shojaie , Mehrdad Farhoudi

When dealing with highly accurate modeling of time and frequency transfers into arbitrarily moving dielectrics medium, it may be convenient to work with Gordon's optical spacetime metric rather than the usual physical spacetime metric.…

General Relativity and Quantum Cosmology · Physics 2020-03-25 Adrien Bourgoin

Time remains one of the least well understood concepts in physics, most notably in quantum mechanics. A central goal is to find the fundamental limits of measuring time. One of the main obstacles is the fact that time is not an observable…

Quantum Physics · Physics 2017-08-08 Paul Erker , Mark T. Mitchison , Ralph Silva , Mischa P. Woods , Nicolas Brunner , Marcus Huber

A proper time observable for a quantum clock is introduced and it is found that the proper time read by one clock conditioned on another clock reading a different proper time obeys classical time dilation in accordance with special…

General Relativity and Quantum Cosmology · Physics 2023-01-04 Takeshi Chiba , Shunichiro Kinoshita

The 3-space of a universe model is defined at a certain simultaneity. Hence space depends on which time is used. We find a general formula generating all known transformations to conformally flat spacetime coordinates, and work out the…

General Relativity and Quantum Cosmology · Physics 2011-03-25 Oyvind Gron , Steinar Johannesen

Several physical concepts, including the concept of time, are clarified herein by taking into account existing experimental data. In addition, the missing links among these physical concepts are established. This allows us to take another…

General Physics · Physics 2022-10-04 Robert Sadykov