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Related papers: Did time begin? Will time end?

200 papers

We argue that whether the universe is infinite or finite is less crucial than usually supposed. Paradoxes of repeating behaviour in the infinite, or eternal inflationary, universe can be alleviated by a realistic definition of differing…

General Relativity and Quantum Cosmology · Physics 2009-11-10 D. H. Coule

The time evolution of the universe is usually mathematically described under a continuous time and thus time reversible. Here, the consequences of studying the evolution of a homogenous isotropic universe by time continuous reversible…

General Physics · Physics 2019-10-23 Roland Riek

The Block Universe idea, representing spacetime as a fixed whole, suggests the flow of time is an illusion: the entire universe just is, with no special meaning attached to the present time. This view is however based on time-reversible…

General Relativity and Quantum Cosmology · Physics 2009-11-11 George F. R. Ellis

Two of the major achievements of Stephen Hawking are described in elementary terms. They are his work on the beginning of the universe and his work on the end of black holes. These are perhaps the scientific achievements for which he is…

History and Philosophy of Physics · Physics 2022-10-12 James Hartle

I present a discussion of some open issues in the philosophy of space-time theories. Emphasis is put on the ontological nature of space and time, the relation between determinism and predictability, the origin of irreversible processes in…

History and Philosophy of Physics · Physics 2015-03-19 Gustavo E. Romero

One hundred years ago we did not know how stars generate energy, the age of the Universe was thought to be only millions of years, and our Milky Way galaxy was the only galaxy known. Today, we know that we live in an evolving and expanding…

Astrophysics · Physics 2008-11-26 Michael S. Turner , J. Anthony Tyson

We provide a discussion of some main ideas in our project about the physical foundation of the time concept in cosmology. It is standard to point to the Planck scale (located at $\sim 10^{-43}$ seconds after a fictitious "Big Bang" point)…

General Relativity and Quantum Cosmology · Physics 2016-03-18 Svend E. Rugh , Henrik Zinkernagel

The expansion of our universe, when followed backward in time, implies that it emerged from a phase of huge density, the big bang. These stages are so extreme that classical general relativity combined with matter theories is not able to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Martin Bojowald

``One could imagine that as a result of enormously extended astronomical experience, the entire universe consists of countless identical copies of our Milky Way, that the infinite space can be partitioned into cubes each containing an…

Astrophysics · Physics 2007-05-23 Jean-Pierre Luminet , Boudewijn F. Roukema

The advent of the 1905 theory of relativity is rightly considered as a breakthrough moment in the history of physics; in particular. it is widely accepted that it brought a new conception of space and time. The purpose of this work is to…

History and Philosophy of Physics · Physics 2017-09-15 Mario Bacelar Valente

In a previous paper we proposed a new approach to the beginning of inflation -- a lingering universe. The universe begins in a lingering state with a nearly vanishing Hubble parameter. This calls into question the absolute age of the…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-09 Brandon Melcher , Arnab Pradhan , Scott Watson

It is advisable to avoid and, even better, demystify such grandiose terms as "infinity" or "singularity" in the description of the cosmos. Its proliferation does not positively contribute to the understanding of key concepts that are…

General Physics · Physics 2023-09-11 Emilio Elizalde

Intuitively, the totality of physical reality -- the Cosmos -- has a beginning only if (i) all parts of the Cosmos agree on the direction of time (the Direction Condition) and (ii) there is a boundary to the past of all non-initial…

History and Philosophy of Physics · Physics 2023-08-28 Daniel Linford

Last couple of decades have been the golden age for cosmology. High quality data confirmed the broad paradigm of standard cosmology but have thrusted upon us a preposterous composition for the universe which defies any simple explanation,…

General Relativity and Quantum Cosmology · Physics 2016-11-23 T. Padmanabhan

We investigate the cosmological behavior in a universe governed by time asymmetric extensions of general relativity, which is a novel modified gravity based on the addition of new, time-asymmetric, terms on the Hamiltonian framework, in a…

General Relativity and Quantum Cosmology · Physics 2015-11-11 Genly Leon , Emmanuel N. Saridakis

A new varying-$c$ cosmological model constructed using two additional assumptions, which was introduced in our previous work, is briefly reviewed and the dynamic equation of the model is derived distinctly from a semi-Newtonian approach.…

General Relativity and Quantum Cosmology · Physics 2010-09-28 Hossein Shojaie , Mehrdad Farhoudi

Current theoretical physics suggests the flow of time is an illusion: the entire universe just is, with no special meaning attached to the present time. This paper points out that this view, in essence represented by usual space-time…

General Relativity and Quantum Cosmology · Physics 2008-12-02 George F R Ellis

For a few years now, cosmology has a standard model. By this term, we mean a consistent theoretical background which is at the same time simple and broad enough to offer coherent explanations for the vast majority of cosmological phenomena.…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-26 Matthias Bartelmann

We put forward a multi-time theory, in frame of which the cosmic acceleration is a natural phenomenon without cosmological constant or anything like that. The main point of this theory is that each of the gravity interaction and…

General Relativity and Quantum Cosmology · Physics 2010-04-16 Hongsheng Zhang

Many believe that the deep question of "why is there something rather than nothing?" is unanswerable. The universe just is and no further explanation for its existence is possible. In this paper I explain why this question must have an…

General Physics · Physics 2012-05-15 Peter Lynds