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Neil Turok Explains The Cyclic Universe Theory
Neil Turok Explains The Cyclic Universe Theory
Published: 2014/11/04
Channel: NourFoundation
Cyclic Universe
Cyclic Universe
Published: 2010/12/07
Channel: lucien khan
Cyclic Universe "Part
Cyclic Universe "Part '2" - (A Beginning and an End)
Published: 2013/07/22
Channel: lucien khan
Roger Penrose - Cyclic Universe Model
Roger Penrose - Cyclic Universe Model
Published: 2007/04/29
Channel: Gravitationalist
Cyclical Universe Theory   Origin of the Universe
Cyclical Universe Theory Origin of the Universe
Published: 2017/04/13
Channel: Universe
Business Model Innovation
Business Model Innovation
Published: 2013/10/22
Channel: HSGUniStGallen
Multiverse: An Alternative Theory
Multiverse: An Alternative Theory
Published: 2014/04/08
Channel: World Science Festival
Cyclic 7 Years Anniversary @ Iasi 11.03.2017 ( aftermovie)
Cyclic 7 Years Anniversary @ Iasi 11.03.2017 ( aftermovie)
Published: 2017/03/27
Channel: Cyclic Agency
Eskatozoa - Evidence Of Cyclic Universe
Eskatozoa - Evidence Of Cyclic Universe
Published: 2016/01/10
Channel: worlocked777
Cyclic Model of the Universe
Cyclic Model of the Universe
Published: 2017/05/14
Channel: digitalfruit
cyclical model of supervision essays
cyclical model of supervision essays
Published: 2016/11/30
Channel: Евгений Суворкин
Before the big bang 2 - Conformal Cyclic Cosmology explained
Before the big bang 2 - Conformal Cyclic Cosmology explained
Published: 2014/01/24
Channel: skydivephil
Model Test Flow Builder: Handling Cyclic flows
Model Test Flow Builder: Handling Cyclic flows
Published: 2016/10/04
Channel: Model Based Testing
Cyclic model
Cyclic model
Published: 2015/05/12
Channel: Bryan Palmer
The Cyclic Ekpyrotic Model
The Cyclic Ekpyrotic Model
Published: 2010/06/21
Channel: drcraigvideos
Creative Cyclic Model with full-bodied event horizons
Creative Cyclic Model with full-bodied event horizons
Published: 2015/06/08
Channel: digitalfruit
Cyclic Universe "Part 1" - (Debunking the Big Bang)
Cyclic Universe "Part 1" - (Debunking the Big Bang)
Published: 2013/07/19
Channel: lucien khan
Ekpyrotic Cyclic Universe - Stephen Barr, William Lane Craig, Alexander Vilenkin
Ekpyrotic Cyclic Universe - Stephen Barr, William Lane Craig, Alexander Vilenkin
Published: 2013/10/13
Channel: Chris Carlascio
cyclic model of Gorillas
cyclic model of Gorillas
Published: 2011/01/23
Channel: cat yeung
Creative Cyclic Model showing fluid flow
Creative Cyclic Model showing fluid flow
Published: 2016/09/09
Channel: digitalfruit
World Science U Live Session: Paul Steinhardt
World Science U Live Session: Paul Steinhardt
Published: 2015/10/27
Channel: World Science U
The Model - live @ Cyclic 7 Years Anniversary, Iasi - march 2017
The Model - live @ Cyclic 7 Years Anniversary, Iasi - march 2017
Published: 2017/03/18
Channel: The Model / Adult Central
Wheeler
Wheeler's curriculum model
Published: 2016/02/07
Channel: Marguerite Beckford
Creative Cyclic Model in playful 3-D
Creative Cyclic Model in playful 3-D
Published: 2012/09/23
Channel: digitalfruit
Cyclic Model proves Hinduism
Cyclic Model proves Hinduism's concept of the Universe H H Swami Sathyananda Saraswathi Tiruvadikal
Published: 2011/08/11
Channel: Sunil Nair
Two Paul Steinhardt Projects: The "Cyclic Universe" and "Quasicrystals"
Two Paul Steinhardt Projects: The "Cyclic Universe" and "Quasicrystals"
Published: 2014/01/14
Channel: WGBHForum
The Model @ Cyber by Cyclic @ Casa Presei 7.04.2017
The Model @ Cyber by Cyclic @ Casa Presei 7.04.2017
Published: 2017/04/19
Channel: Cyclic Agency
Creative Cyclic Model in playful 3-D [alt view]
Creative Cyclic Model in playful 3-D [alt view]
Published: 2012/09/23
Channel: digitalfruit
Inflationary cosmology on trial
Inflationary cosmology on trial
Published: 2011/04/04
Channel: Vanderbilt University
The Oscillating Universe Theory Fails - William Lane Craig, PhD
The Oscillating Universe Theory Fails - William Lane Craig, PhD
Published: 2012/07/31
Channel: firstcauseargument
Reenginering systems Using The cyclic Model  Case Study: The University System Financial (SUF)
Reenginering systems Using The cyclic Model Case Study: The University System Financial (SUF)
Published: 2016/11/16
Channel: JOSE ALONSO Pérez-CRUZ
The Model @ Cyclic 7 Years Anniversary in Iasi/ Zona de agrement Ciric (11.03.2017)
The Model @ Cyclic 7 Years Anniversary in Iasi/ Zona de agrement Ciric (11.03.2017)
Published: 2017/03/17
Channel: Cyclic Agency
Roger Penrose - Modelo de Universo Cíclico (Cyclic Universe Model)
Roger Penrose - Modelo de Universo Cíclico (Cyclic Universe Model)
Published: 2010/04/22
Channel: lardhat
'The Cyclical Model,' COSMOGONY, July 2013
Published: 2013/07/27
Channel: John Likides
Cyclic Organic Farming model
Cyclic Organic Farming model
Published: 2015/12/16
Channel: SunShineLabz - Science Projects
Simulation of Concrete Shear Wall Under Cyclic Lateral Loading
Simulation of Concrete Shear Wall Under Cyclic Lateral Loading
Published: 2015/10/21
Channel: Ioannis Koutromanos
How to setup Cyclic Symmetry model in ANSYS Workbench Mechanical
How to setup Cyclic Symmetry model in ANSYS Workbench Mechanical
Published: 2016/08/13
Channel: SimuTech Group
Ontological Randomness and a Cyclic Universe
Ontological Randomness and a Cyclic Universe
Published: 2016/06/09
Channel: David R
Oscillating Universe Theory
Oscillating Universe Theory
Published: 2016/01/28
Channel: hunter wood
Cyclic steps in model bedrock of silica flour and kaolinite
Cyclic steps in model bedrock of silica flour and kaolinite
Published: 2016/02/08
Channel: UConn Sedimentology And Stratigraphy
Oscillating Models
Oscillating Models
Published: 2010/06/28
Channel: drcraigvideos
Two Paul Steinhardt Projects: "Cyclic Universe" and "Quasicrystals"
Two Paul Steinhardt Projects: "Cyclic Universe" and "Quasicrystals"
Published: 2013/05/07
Channel: Yvonne Stapp
How work Epic cyclic gear train model
How work Epic cyclic gear train model
Published: 2016/09/16
Channel: satish yadav
Oscillating Universe
Oscillating Universe
Published: 2013/09/26
Channel: Chris Carlascio
Cyclic Organic Farming..
Cyclic Organic Farming..
Published: 2016/08/07
Channel: Taranjeet Singh
Oscillating Universe Theory
Oscillating Universe Theory
Published: 2013/10/09
Channel: Piller Productions
Dr. William Craig on The Cyclic Ekpyrotic Model
Dr. William Craig on The Cyclic Ekpyrotic Model
Published: 2012/05/02
Channel: DrWilliamCraigVideos
Innovation Management Seminar (10.26.13), Part II
Innovation Management Seminar (10.26.13), Part II
Published: 2014/01/30
Channel: Stavros Sindakis
Cyclic Redundancy Check(CRC) example
Cyclic Redundancy Check(CRC) example
Published: 2015/05/12
Channel: The BootStrappers
Helicopter flight model test - cyclic/collective control
Helicopter flight model test - cyclic/collective control
Published: 2017/05/30
Channel: Worstplayer
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WIKIPEDIA ARTICLE

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A cyclic model (or oscillating model) is any of several cosmological models in which the universe follows infinite, or indefinite, self-sustaining cycles. For example, the oscillating universe theory briefly considered by Albert Einstein in 1930 theorized a universe following an eternal series of oscillations, each beginning with a big bang and ending with a big crunch; in the interim, the universe would expand for a period of time before the gravitational attraction of matter causes it to collapse back in and undergo a bounce.

Overview[edit]

In the 1920s, theoretical physicists, most notably Albert Einstein, considered the possibility of a cyclic model for the universe as an (everlasting) alternative to the model of an expanding universe. However, work by Richard C. Tolman in 1934 showed that these early attempts failed because of the cyclic problem: according to the Second Law of Thermodynamics, entropy can only increase.[1] This implies that successive cycles grow longer and larger. Extrapolating back in time, cycles before the present one become shorter and smaller culminating again in a Big Bang and thus not replacing it. This puzzling situation remained for many decades until the early 21st century when the recently discovered dark energy component provided new hope for a consistent cyclic cosmology.[2] In 2011, a five-year survey of 200,000 galaxies and spanning 7 billion years of cosmic time confirmed that "dark energy is driving our universe apart at accelerating speeds."[3][4]

One new cyclic model is a brane cosmology model of the creation of the universe, derived from the earlier ekpyrotic model. It was proposed in 2001 by Paul Steinhardt of Princeton University and Neil Turok of Cambridge University. The theory describes a universe exploding into existence not just once, but repeatedly over time.[5][6] The theory could potentially explain why a repulsive form of energy known as the cosmological constant, which is accelerating the expansion of the universe, is several orders of magnitude smaller than predicted by the standard Big Bang model.

A different cyclic model relying on the notion of phantom energy was proposed in 2007 by Lauris Baum and Paul Frampton of the University of North Carolina at Chapel Hill.[7]

Other cyclic models include Conformal cyclic cosmology and Loop quantum cosmology.

The Steinhardt–Turok model[edit]

In this cyclic model, two parallel orbifold planes or M-branes collide periodically in a higher-dimensional space.[8] The visible four-dimensional universe lies on one of these branes. The collisions correspond to a reversal from contraction to expansion, or a big crunch followed immediately by a big bang. The matter and radiation we see today were generated during the most recent collision in a pattern dictated by quantum fluctuations created before the branes. After billions of years the universe reached the state we observe today; after additional billions of years it will ultimately begin to contract again. Dark energy corresponds to a force between the branes, and serves the crucial role of solving the monopole, horizon, and flatness problems. Moreover, the cycles can continue indefinitely into the past and the future, and the solution is an attractor, so it can provide a complete history of the universe.

As Richard C. Tolman showed, the earlier cyclic model failed because the universe would undergo inevitable thermodynamic heat death.[1] However, the newer cyclic model evades this by having a net expansion each cycle, preventing entropy from building up. However, there remain major open issues in the model. Foremost among them is that colliding branes are not understood by string theorists, and nobody knows if the scale invariant spectrum will be destroyed by the big crunch. Moreover, as with cosmic inflation, while the general character of the forces (in the ekpyrotic scenario, a force between branes) required to create the vacuum fluctuations is known, there is no candidate from particle physics.[9]

The Baum–Frampton model[edit]

This more recent cyclic model of 2007 makes a different technical assumption concerning the equation of state of the dark energy which relates pressure and density through a parameter w.[7][10] It assumes w < −1 (a condition called phantom energy) throughout a cycle, including at present. (By contrast, Steinhardt–Turok assume w is never less than −1.) In the Baum–Frampton model, a septillionth (or less) of a second (i.e. 10−24 seconds or less) before the would-be Big Rip, a turnaround occurs and only one causal patch is retained as our universe. The generic patch contains no quark, lepton or force carrier; only dark energy – and its entropy thereby vanishes. The adiabatic process of contraction of this much smaller universe takes place with constant vanishing entropy and with no matter including no black holes which disintegrated before turnaround.

The idea that the universe "comes back empty" is a central new idea of this cyclic model, and avoids many difficulties confronting matter in a contracting phase such as excessive structure formation, proliferation and expansion of black holes, as well as going through phase transitions such as those of QCD and electroweak symmetry restoration. Any of these would tend strongly to produce an unwanted premature bounce, simply to avoid violation of the second law of thermodynamics. The surprising w < −1 condition may be logically inevitable in a truly infinitely cyclic cosmology because of the entropy problem. Nevertheless, many technical back up calculations are necessary to confirm consistency of the approach. Although the model borrows ideas from string theory, it is not necessarily committed to strings, or to higher dimensions, yet such speculative devices may provide the most expeditious methods to investigate the internal consistency. The value of w in the Baum–Frampton model can be made arbitrarily close to, but must be less than, −1.

Cyclic steady-state model[edit]

Astrophysicist Geoffrey Burbidge proposes a realistic cyclic steady-state model (2008) in which the universe continuously goes through stages of expansion and contraction, each cycle on a length far greater than 1012 years, with very hot and massive active galaxies and black holes playing roles in the formation of elements in each cycle. The model attempts to address issues with standard Lambda-CDM cosmology, including the lack of viable or confirmed non-baryonic dark matter sources, uncertainty regarding dark energy, early galaxy formation and constraints on inflation, while also reconciling and taking account with recent observations and element abundances without the need of additional new physics beyond the Standard Model.[11]

Other cyclic models[edit]

  • Conformal cyclic cosmology—a general relativity based theory due to Roger Penrose in which the universe expands until all the matter decays and is turned to light—so there is nothing in the universe that has any time or distance scale associated with it. This permits it to become identical with the Big Bang, so starting the next cycle.
  • Loop quantum cosmology which predicts a "quantum bridge" between contracting and expanding cosmological branches.

See also[edit]

Physical cosmologies:

Religion:

Notes[edit]

  1. ^ a b R. C. Tolman (1987) [1934]. Relativity, Thermodynamics, and Cosmology. New York: Dover. ISBN 0-486-65383-8. LCCN 34032023. 
  2. ^ P. H. Frampton (2006). "On Cyclic Universes". arXiv:astro-ph/0612243Freely accessible. 
  3. ^ Dark Energy Is Driving Universe Apart: NASA's Galaxy Evolution Explorer Finds Dark Energy Repulsive
  4. ^ The WiggleZ Dark Energy Survey: Direct constraints on blue galaxy intrinsic alignments at intermediate redshifts
  5. ^ P. J. Steinhardt, N. Turok (2001). "Cosmic Evolution in a Cyclic Universe". Physical Review D. 65 (12): 126003. Bibcode:2002PhRvD..65l6003S. arXiv:hep-th/0111098Freely accessible. doi:10.1103/PhysRevD.65.126003. 
  6. ^ P. J. Steinhardt, N. Turok (2001). "A Cyclic Model of the Universe". Science. 296 (5572): 1436–1439. Bibcode:2002Sci...296.1436S. PMID 11976408. arXiv:hep-th/0111030Freely accessible. doi:10.1126/science.1070462. 
  7. ^ a b L. Baum, P. H. Frampton (2007). "Entropy of Contracting Universe in Cyclic Cosmology". Modern Physics Letters A. 23: 33. Bibcode:2008MPLA...23...33B. arXiv:hep-th/0703162Freely accessible. doi:10.1142/S0217732308026170. 
  8. ^ P. J. Steinhardt, N. Turok (2004). "The Cyclic Model Simplified". New Astronomy Reviews. 49 (2–6): 43–57. Bibcode:2005NewAR..49...43S. arXiv:astro-ph/0404480Freely accessible. doi:10.1016/j.newar.2005.01.003. 
  9. ^ P. Woit (2006). Not Even Wrong. London: Random House. ISBN 978-0-09-948864-4. 
  10. ^ L. Baum and P. H. Frampton (2007). "Turnaround in Cyclic Cosmology". Physical Review Letters. 98 (7): 071301. Bibcode:2007PhRvL..98g1301B. PMID 17359014. arXiv:hep-th/0610213Freely accessible. doi:10.1103/PhysRevLett.98.071301. 
  11. ^ Burbridge, Geoffrey (14 November 2008). "A Realistic Cosmological Model Based on Observations and Some Theory Developed over the Last 90 Years". arXiv:0811.2402Freely accessible [astro-ph]. 

Further reading[edit]

External links[edit]

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