* Astronomy

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RE: TIME

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Controversially, Physicist Argues Time Is Real

Is time real, or the ultimate illusion?
Most physicists would say the latter, but Lee Smolin challenges this orthodoxy in his new book, "Time Reborn" (Houghton Mifflin Harcourt, April 2013), which he discussed here Wednesday (April 24) at the Rubin Museum of Art.
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The Physics of Time

Thu, 18 Dec 08

Duration: 43 mins

Melvyn Bragg and guests discuss the physics of time. With Jim Al-Khalili, Ian Stewart and Monica Grady.

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BBC Podcast: Measurement of Time

Thu, 29 Mar 12

Duration: 42 mins

Melvyn Bragg and his guests discuss the measurement of time. Early civilisations used the movements of heavenly bodies to tell the time, then mechanical clocks emerged in Europe in the medieval period. For hundreds of years clocks were inaccurate but now atomic clocks are capable of keeping time to a second in 15 million years. Melvyn Bragg is joined by Kristen Lippincott, Former Director of the Royal Observatory, Greenwich; Jim Bennett, Director of the Museum of the History of Science at the University of Oxford and Jonathan Betts, Senior Curator of Horology at the Royal Observatory, Greenwich.

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Cosmic Journeys: When Will Time End?

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Title: Hyperbolic metamaterial interfaces: Hawking radiation from Rindler horizons and the "end of time"
Authors: Igor I. Smolyaninov, Ehren Hwang, Evgenii Narimanov

Extraordinary rays in a hyperbolic metamaterial behave as particle world lines in a three dimensional (2+1) Minkowski spacetime. We analyse electromagnetic field behaviour at the boundaries of this effective spacetime depending on the boundary orientation. If the boundary is perpendicular to the space-like direction in the metamaterial, an effective Rindler horizon may be observed which produces Hawking radiation. On the other hand, if the boundary is perpendicular to the time-like direction an unusual physics situation is created, which can be called "the end of time". It appears that in the lossless approximation electromagnetic field diverges at the interface in both situations. Experimental observations of the "end of time" using plasmonic metamaterials confirm this conclusion.

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The Origin of the Universe and the Arrow of Time

Sean Carroll, Ph.D.
Senior Research Associate in Physics
California Institute of Technology

Villanova University

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Louis Armstrong We Have All The Time In The World

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* Einstein's general theory of relativity predicts that time ends at moments called singularities, such as when matter reaches the center of a black hole or the universe collapses in a "big crunch." Yet the theory also predicts that singularities are physically impossible.
* A way to resolve this paradox is to consider times death as gradual rather than abrupt. Time might lose its many attributes one by one: its directionality, its notion of duration and its role in ordering events causally. Finally, time might give way to deeper, timeless physics.

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Title: Does the Cosmos have two times? Multi-time and cosmic acceleration
Authors: Hongsheng Zhang
(Version v6)

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 electromagnetic interaction has its own time, respectively. Also we give a concrete model of this theory which can exactly simulate \Lambda CDM. Further we discuss the possible observations which may improve this theory in the future.

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