Quantum measurement

Top-down cosmology

In theoretical physics, top-down cosmology is a proposal to regard the many possible past histories of a given event as having real existence. This idea of multiple histories has been applied to cosmology, in a theoretical interpretation in which the universe has multiple possible cosmologies, and in which reasoning backwards from the current state of the universe to a quantum superposition of possible cosmic histories makes sense. Stephen Hawking has argued that the principles of quantum mechanics forbid a single cosmic history, and has proposed cosmological theories in which the lack of a past boundary condition naturally leads to multiple histories, called the 'no-boundary proposal', the proposed Hartle–Hawking state. According to Hawking and Thomas Hertog, "The top-down approach we have described leads to a profoundly different view of cosmology, and the relation between cause and effect. Top down cosmology is a framework in which one essentially traces the histories backwards, from a spacelike surface at the present time. The noboundary histories of the universe thus depend on what is being observed, contrary to the usual idea that the universe has a unique, observer independent history." (Wikipedia).

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Teach Astronomy - Cosmology

http://www.teachastronomy.com/ Cosmology is the study of the universe, its history, and everything in it. It comes from the Greek root of the word cosmos for order and harmony which reflected the Greek belief that the universe was a harmonious entity where everything worked in concert to

From playlist 22. The Big Bang, Inflation, and General Cosmology

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What is the modern view of the cosmological constant?

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From playlist Science Unplugged: Cosmology

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What is the shape of the universe?

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From playlist Science Unplugged: Cosmology

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What happened during the Big Bang?

Subscribe to our YouTube Channel for all the latest from World Science U. Visit our Website: http://www.worldscienceu.com/ Like us on Facebook: https://www.facebook.com/worldscienceu Follow us on Twitter: https://twitter.com/worldscienceu

From playlist Science Unplugged: Cosmology

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Cosmology: A Big Bang and the Beginning of the Universe

If we want to learn about the universe, we have to start at the very beginning. How and when did the universe begin? Is it even possible to know about such things? Yes, it is! That's what cosmology is all about, the origin and development of the universe. Let's go over what astronomers kno

From playlist Astronomy/Astrophysics

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According to the big bang, can you give a thumbnail sketch of how the universe has evolved?

According to the big bang, can you give a thumbnail sketch of how the universe has evolved?

From playlist Science Unplugged: Cosmology

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Teach Astronomy - Newton's Cosmology

http://www.teachastronomy.com/ Newton's theory of gravity set the stage for physical cosmology, a study of the universe based on the idea of laws of physics that applied everywhere throughout space, and it gave rise to the idea of a clockwork universe, although we now know the universe is

From playlist 22. The Big Bang, Inflation, and General Cosmology

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Teach Astronomy - Scale of the Universe

http://www.teachastronomy.com/ The best way to think of the cosmological redshift z is in terms of the scale of the universe. We see regions near us as they are now, nothing has changed. That's at redshift zero, z equals zero, but in general redshift is defined as the present day scale o

From playlist 22. The Big Bang, Inflation, and General Cosmology

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Cosmology with Gravitational Waves (Lecture 3) by Archisman Ghosh

Program Cosmology - The Next Decade ORGANIZERS : Rishi Khatri, Subha Majumdar and Aseem Paranjape DATE : 03 January 2019 to 25 January 2019 VENUE : Ramanujan Lecture Hall, ICTS Bangalore The great observational progress in cosmology has revealed some very intriguing puzzles, the most i

From playlist Cosmology - The Next Decade

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Quantum Circuit Cosmology - S. Carroll - Workshop 1 - CEB T3 2018

Sean Carroll (California Institute) / 17.09.2018 Quantum Circuit Cosmology ---------------------------------- Vous pouvez nous rejoindre sur les réseaux sociaux pour suivre nos actualités. Facebook : https://www.facebook.com/InstitutHenriPoincare/ Twitter : https://twitter.com/InHenriPo

From playlist 2018 - T3 - Analytics, Inference, and Computation in Cosmology

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Cosmology | Lecture 8

Lecture 8 of Leonard Susskind's course on Cosmology. Recorded March 16, 2009 at Stanford University. This Stanford Continuing Studies course is the fifth of a six-quarter sequence of classes exploring the essential theoretical foundations of modern physics. The topics covered in this co

From playlist Lecture Collection | Modern Physics: Cosmology

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Aspects of Eternal Inflation, part 3 - Leonard Susskind

Aspects of Eternal Inflation, part 3 Leonard Susskind Stanford University July 20, 2011

From playlist PiTP 2011

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Lattice Holographic Cosmology and the Renormalization of the 2-Point Function...by Kostas Skenderis

PROGRAM NONPERTURBATIVE AND NUMERICAL APPROACHES TO QUANTUM GRAVITY, STRING THEORY AND HOLOGRAPHY (HYBRID) ORGANIZERS: David Berenstein (University of California, Santa Barbara, USA), Simon Catterall (Syracuse University, USA), Masanori Hanada (University of Surrey, UK), Anosh Joseph (II

From playlist NUMSTRING 2022

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Cosmology with Time Delay Strong Lensing by Kenneth Wong

Program Cosmology - The Next Decade ORGANIZERS : Rishi Khatri, Subha Majumdar and Aseem Paranjape DATE : 03 January 2019 to 25 January 2019 VENUE : Ramanujan Lecture Hall, ICTS Bangalore The great observational progress in cosmology has revealed some very intriguing puzzles, the most i

From playlist Cosmology - The Next Decade

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Uncovering Dark Matter Physics:from the Early Universe to near Field Cosmology by Vera Gluscevic

PROGRAM LESS TRAVELLED PATH TO THE DARK UNIVERSE ORGANIZERS: Arka Banerjee (IISER Pune), Subinoy Das (IIA, Bangalore), Koushik Dutta (IISER, Kolkata), Raghavan Rangarajan (Ahmedabad University) and Vikram Rentala (IIT Bombay) DATE & TIME: 13 March 2023 to 24 March 2023 VENUE: Ramanujan

From playlist LESS TRAVELLED PATH TO THE DARK UNIVERSE

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Where in the World are SUSY & WIMPS? - Nima Arkani-Hamed

Prospects in Theoretical Physics Particle Physics at the LHC and Beyond Topic: Where in the World are SUSY & WIMPS? Speaker: Nima Arkani-Hamed Date: July 20th, 2017

From playlist PiTP 2017

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Cosmological Perturbation Theory / CMB (Lecture 2) by D Pogosyan

Program Cosmology - The Next Decade ORGANIZERS : Rishi Khatri, Subha Majumdar and Aseem Paranjape DATE : 03 January 2019 to 25 January 2019 VENUE : Ramanujan Lecture Hall, ICTS Bangalore The great observational progress in cosmology has revealed some very intriguing puzzles, the most i

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GR And QG: The Next Hundred Years by T Padmanabhan

21 November 2016 to 10 December 2016 VENUE Ramanujan Lecture Hall, ICTS Bangalore Quantum Theory has passed all experimental tests, with impressive accuracy. It applies to light and matter from the smallest scales so far explored, up to the mesoscopic scale. It is also a necessary ingredie

From playlist Fundamental Problems of Quantum Physics

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How Big is the Universe? Part 1 of 2

An explanation of the size of the observable universe and why we cannot see beyond it. together with a forward look to a time when distant galaxies will no longer be visible.

From playlist Cosmology

Related pages

Consistent histories | Stephen Hawking