Big Crunch

Last updated
An animation of the expected behavior of a Big Crunch Big Crunch.gif
An animation of the expected behavior of a Big Crunch

The Big Crunch is a hypothetical scenario for the ultimate fate of the universe, in which the expansion of the universe eventually reverses and the universe recollapses, ultimately causing the cosmic scale factor to reach zero, an event potentially followed by a reformation of the universe starting with another Big Bang. The vast majority of evidence indicates that this hypothesis is not correct. Instead, astronomical observations show that the expansion of the universe is accelerating rather than being slowed by gravity, suggesting that a Big Chill is more likely. [1] [2] [3] However, some physicists have proposed that a "Big Crunch-style" event could result from a dark energy fluctuation. [4]

Contents

The theory dates back to 1922, with Russian physicist Alexander Friedmann creating a set of equations showing that the end of the universe depends on its density. It could either expand or contract rather than stay stable. With enough matter, gravity could stop the universe's expansion and eventually reverse it. This reversal would result in the universe collapsing on itself, not too dissimilar to a black hole. [5]

The ending of the Big Crunch would get filled with radiation from stars and high-energy particles; when this is condensed and blueshifted to higher energy, it would be intense enough to ignite the surface of stars before they collide. [6] In the final moments, the universe would be one large fireball with a temperature of infinity, and at the absolute end, neither time, nor space would remain. [7]

Overview

The Big Crunch [8] scenario hypothesized that the density of matter throughout the universe is sufficiently high that gravitational attraction will overcome the expansion which began with the Big Bang. The FLRW cosmology can predict whether the expansion will eventually stop based on the average energy density, Hubble parameter, and cosmological constant. If the expansion stopped, then contraction will inevitably follow, accelerating as time passes and finishing the universe in a kind of gravitational collapse, turning the universe into a black hole.

Experimental evidence in the late 1990s and early 2000s (namely the observation of distant supernovas as standard candles; and the well-resolved mapping of the cosmic microwave background) [9] led to the conclusion that the expansion of the universe is not getting slowed by gravity but is instead accelerating. The 2011 Nobel Prize in Physics was awarded to researchers who contributed to this discovery. [1]

The Big Crunch theory also leads into another hypothesis known as the Big Bounce, in which after the big crunch destroys the universe, it does a sort of bounce, causing another big bang. [10] This could potentially repeat forever in a phenomenon known as a cyclic universe.

History

Richard Bentley, a churchman, and a scholar, in preparation for a lecture on Newton's theories and the rejection of atheism, sent a letter out to Sir Isaac Newton,

"If we're in a finite universe and all stars attract each other together, would they not all collapse to a singular point, and if we're in an infinite universe with infinite stars, would infinite forces in every direction not affect all of those stars?"

This question is known as Bentley's paradox, [11] a proto-theory of the Big Crunch. Although, it is now known that stars move around and aren't static.

Newton's copy of Principia, the book that caused Richard Bentley to send Newton the letter. Newton's Annotated copy of his Principia Mathematica.jpg
Newton's copy of Principia, the book that caused Richard Bentley to send Newton the letter.

Einstein's cosmological constant

Albert Einstein favored a completely unchanging model of the universe. He collaborated in 1917 with Dutch astronomer Willem de Sitter to help demonstrate that the theory of general relativity would work with a static model; Willem demonstrated that his equations could describe a very simple universe. Finding no problems initially, scientists adapted the model to describe the universe. However, they ran into a different form of Bentley's paradox. [13]

The theory of general relativity also described the universe as restless, contradicting information he found. Einstein realized that for a static universe to exist—which was observed at the time—an anti-gravity would be needed to counter the gravity contracting the universe together, adding an extra force that would ruin the equations in the theory of relativity. In the end, the cosmological constant, the name for the anti-gravity force, was added to the theory of relativity. [14]

Discovery of Hubble's law

Scatter plot that Hubble used to find the Hubble constant. Hubble constant.JPG
Scatter plot that Hubble used to find the Hubble constant.

Edwin Hubble working in the Mount Wilson Observatory took measurements of the distances of galaxies and paired them with Vesto Silpher and Milton Humason's measurements of redshifts associated with said galaxies. He discovered a rough proportionality between the redshift of an object and its distance. Hubble plotted a trend line from 46 galaxies, studying and obtaining the Hubble Constant, which he deduced to be 500 km/s/Mpc, nearly seven times than what it is considered today, but still giving the proof that the universe was expanding and was not a static object. [15]

Abandonment of the cosmological constant

After publishing Hubble's discovery, Einstein completely abandoned the cosmological constant. In their simplest form, the equations generated a model of the universe that expanded or contracted. Contradicting what was observed, hence the creation of the cosmological constant. [16] After the confirmation that the universe was expanding, Einstein called his assumption that the universe was static his "biggest mistake." In 1931, Einstein visited Hubble to thank him for "providing the basis of modern cosmology." [17]

After this discovery, Einstein's and Newton's models of a contracting, yet static universe, were dropped for the model expanding universe model.

Cyclic universes

A theory called "Big Bounce" proposes that the universe could collapse to the state where it began and then initiate another Big Bang, so in this way, the universe would last forever but would pass through phases of expansion (Big Bang) and contraction (Big Crunch). [10] This means that there may be a universe in a state of constant Big Bangs and Big Crunches.

Cyclic universes were briefly considered by Albert Einstein in 1931. He theorized that there was a universe before the Big Bang, which ended in a Big Crunch, which could create a Big Bang as a reaction. Our universe could be in a cycle of expansion and contraction, a cycle possibly going on infinitely.

Ekpyrotic model

Depiction of two branes, the basis of the Ekpyrotic model. D3-brane et D2-brane.PNG
Depiction of two branes, the basis of the Ekpyrotic model.

There are more modern theories of Cyclic universes as well. The Ekpyrotic theory, formed by Paul Steinhardt, states that the Big Bang could have been caused by two parallel orbifold planes, referred to as branes colliding in a higher-dimensional space. [18] The four-dimension universe lies on one of the branes. The collision corresponds to the Big Crunch, then a Big Bang. The matter and radiation around us today are quantum fluctuations from before the branes. After several billion years, the universe has reached its modern state, and it will start contracting in another several billion years. dark energy corresponds to the force between the branes, allowing for problems, like the flatness and monopole in the previous theories to be fixed. The cycles can also go infinitely into the past and the future, and an attractor allows for a complete history of the universe. [19]

This fixes the problem of the earlier model of the universe going into heat death from entropy buildup. The new model avoids this with a net expansion after every cycle, stopping entropy buildup. However, there are still some flaws in this model. The basis of the theory, branes, are still not understood completely by string theorists, and the possibility that the scale invariant spectrum could be destroyed from the big crunch. While cosmic inflation and the general character of the forces—or the collision of the branes in the Ekpyrotic model—required to make vacuum fluctuations is known. A candidate from particle physics is missing. [20]

Conformal Cyclic Cosmology (CCC) model

A map of the CMB showing different hot spots around the universe. WMAP image of the CMB anisotropy.jpg
A map of the CMB showing different hot spots around the universe.

Physicist Roger Penrose advanced a general relativity-based theory called the conformal cyclic cosmology in which the universe expands until all the matter decays and is turned to light. Since nothing in the universe would have any time or distance scale associated with it, it becomes identical with the Big Bang (resulting in a type of Big Crunch which becomes the next Big Bang, thus starting the next cycle). [21] Penrose and Gurzadyan suggested that signatures of conformal cyclic cosmology could potentially be found in the cosmic microwave background; as of 2020, these have not been detected. [22]

There are also some flaws with this theory as well, skeptics pointed out that in order to match up an infinitely large universe to an infinitely small universe, that all particles must lose their mass when the universe gets old. However, Penrose presented evidence of CCC in the form of rings that had uniform temperature in the CMB, the idea being that these rings would be the signature in our aeon—An aeon being the current cycle of the universe that we're in—was caused by spherical gravitational waves caused by colliding black holes from our previous aeon. [23]

Loop quantum cosmology (LQC)

Loop quantum cosmology is a model of the universe that proposes a "quantum-bridge" between expanding and contracting universes. In this model quantum geometry creates a brand-new force which is negligible at low space-time curvature, but which rises very rapidly in the Planck regime, overwhelming classical gravity and resolving singularities of general relativity. Once the singularities are resolved the conceptual paradigm of cosmology changes, forcing one to revisit the standard issues—such as the horizon problem—from a new perspective. [24]

Under this model, due to quantum geometry, the Big Bang is replaced by the Big Bounce with no assumptions or any fine tuning. The approach of effective dynamics has been used extensively in loop quantum cosmology to describe physics at the Planck scale, and also the beginning of the universe. Numerical simulations have confirmed the validity of effective dynamics, which provides a good approximation of the full loop quantum dynamics. It has been shown when states have very large quantum fluctuations at late times, meaning they do not lead to macroscopic universes as described by general relativity, but the effective dynamics departs from quantum dynamics near bounce and the later universe. In this case, the effective dynamics will overestimate the density at bounce, but it will still capture qualitative aspects extremely well. [25]

Empirical scenarios from physical theories

If a form of quintessence driven by a scalar field evolving down a monotonically decreasing potential that passes sufficiently below zero is the (main) explanation of dark energy and current data (in particular observational constraints on dark energy) is true as well, the accelerating expansion of the Universe would inverse to contraction within the cosmic near-future of the next 100 million years. According to an Andrei-Ijjas-Steinhardt study, the scenario fits "naturally with cyclic cosmologies and recent conjectures about quantum gravity". The study suggests that the slow contraction phase would "endure for a period of order 1 billion y before the universe transitions to a new phase of expansion". [26] [27] [28]

Effects

Paul Davies considered a scenario in which the Big Crunch happens about 100 billion years from the present. In his model, the contracting universe would evolve roughly like the expanding phase in reverse. First, galaxy clusters, and then galaxies, would merge, and the temperature of the cosmic microwave background (CMB) would begin to rise as CMB photons get blueshifted. Stars would eventually become so close together that they begin to collide with each other. Once the CMB becomes hotter than M-type stars (about 500,000 years before the Big Crunch in Davies' model), they would no longer be able to radiate away their heat and would cook themselves until they evaporate; this continues for successively hotter stars until O-type stars boil away about 100,000 years before the Big Crunch. In the last minutes, the temperature of the universe would be so great that atoms and atomic nuclei would break up and get sucked up into already coalescing black holes. At the time of the Big Crunch, all the matter in the universe would be crushed into an infinitely hot, infinitely dense singularity similar to the Big Bang. [29] The Big Crunch may be followed by another Big Bang, creating a new universe. [4]

In culture

In The Restaurant at the End of the Universe , a novel by Douglas Adams, the concept is that a restaurant, Milliways, is set up to allow patrons to observe the end of the Universe, or "Gnab Gib", as it is referred to, as they dine. [30] The term is sometimes used in the mainstream, for example (as "gnaB giB") in Physics I For Dummies and in a posting discussing the Big Crunch. [31]

See also

Related Research Articles

<span class="mw-page-title-main">Big Bang</span> Physical theory describing the expansion of the universe

The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. It was first proposed in 1927 by Roman Catholic priest and physicist Georges Lemaître. Various cosmological models of the Big Bang explain the evolution of the observable universe from the earliest known periods through its subsequent large-scale form. These models offer a comprehensive explanation for a broad range of observed phenomena, including the abundance of light elements, the cosmic microwave background (CMB) radiation, and large-scale structure. The overall uniformity of the universe, known as the flatness problem, is explained through cosmic inflation: a sudden and very rapid expansion of space during the earliest moments. However, physics currently lacks a widely accepted theory of quantum gravity that can successfully model the earliest conditions of the Big Bang.

<span class="mw-page-title-main">Physical cosmology</span> Branch of cosmology which studies mathematical models of the universe

Physical cosmology is a branch of cosmology concerned with the study of cosmological models. A cosmological model, or simply cosmology, provides a description of the largest-scale structures and dynamics of the universe and allows study of fundamental questions about its origin, structure, evolution, and ultimate fate. Cosmology as a science originated with the Copernican principle, which implies that celestial bodies obey identical physical laws to those on Earth, and Newtonian mechanics, which first allowed those physical laws to be understood.

In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe. The inflationary epoch is believed to have lasted from 10−36 seconds to between 10−33 and 10−32 seconds after the Big Bang. Following the inflationary period, the universe continued to expand, but at a slower rate. The re-acceleration of this slowing expansion due to dark energy began after the universe was already over 7.7 billion years old.

<span class="mw-page-title-main">Universe</span> Everything in space and time

The universe is all of space and time and their contents. It comprises all of existence, any fundamental interaction, physical process and physical constant, and therefore all forms of energy and matter, and the structures they form, from sub-atomic particles to entire galaxies. Space and time, according to the prevailing cosmological theory of the Big Bang, emerged together 13.787±0.020 billion years ago, and the universe has been expanding ever since. Today the universe has expanded into an age and size that is physically only in parts observable as the observable universe, which is approximately 93 billion light-years in diameter at the present day, while the spatial size, if any, of the entire universe is unknown.

<span class="mw-page-title-main">Accelerating expansion of the universe</span> Cosmological phenomenon

Observations show that the expansion of the universe is accelerating, such that the velocity at which a distant galaxy recedes from the observer is continuously increasing with time. The accelerated expansion of the universe was discovered in 1998 by two independent projects, the Supernova Cosmology Project and the High-Z Supernova Search Team, which used distant type Ia supernovae to measure the acceleration. The idea was that as type Ia supernovae have almost the same intrinsic brightness, and since objects that are farther away appear dimmer, the observed brightness of these supernovae can be used to measure the distance to them. The distance can then be compared to the supernovae's cosmological redshift, which measures how much the universe has expanded since the supernova occurred; the Hubble law established that the farther away that an object is, the faster it is receding. The unexpected result was that objects in the universe are moving away from one another at an accelerating rate. Cosmologists at the time expected that recession velocity would always be decelerating, due to the gravitational attraction of the matter in the universe. Three members of these two groups have subsequently been awarded Nobel Prizes for their discovery. Confirmatory evidence has been found in baryon acoustic oscillations, and in analyses of the clustering of galaxies.

<span class="mw-page-title-main">Gravitational singularity</span> Condition in which spacetime itself breaks down

A gravitational singularity, spacetime singularity or simply singularity is a condition in which gravity is predicted to be so intense that spacetime itself would break down catastrophically. As such, a singularity is by definition no longer part of the regular spacetime and cannot be determined by "where" or "when". Gravitational singularities exist at a junction between general relativity and quantum mechanics; therefore, the properties of the singularity cannot be described without an established theory of quantum gravity. Trying to find a complete and precise definition of singularities in the theory of general relativity, the current best theory of gravity, remains a difficult problem. A singularity in general relativity can be defined by the scalar invariant curvature becoming infinite or, better, by a geodesic being incomplete.

<i>A Brief History of Time</i> 1988 book by Stephen Hawking

A Brief History of Time: From the Big Bang to Black Holes is a book on theoretical cosmology by English physicist Stephen Hawking. It was first published in 1988. Hawking wrote the book for readers who had no prior knowledge of physics.

The ultimate fate of the universe is a topic in physical cosmology, whose theoretical restrictions allow possible scenarios for the evolution and ultimate fate of the universe to be described and evaluated. Based on available observational evidence, deciding the fate and evolution of the universe has become a valid cosmological question, being beyond the mostly untestable constraints of mythological or theological beliefs. Several possible futures have been predicted by different scientific hypotheses, including that the universe might have existed for a finite and infinite duration, or towards explaining the manner and circumstances of its beginning.

A non-standard cosmology is any physical cosmological model of the universe that was, or still is, proposed as an alternative to the then-current standard model of cosmology. The term non-standard is applied to any theory that does not conform to the scientific consensus. Because the term depends on the prevailing consensus, the meaning of the term changes over time. For example, hot dark matter would not have been considered non-standard in 1990, but would have been in 2010. Conversely, a non-zero cosmological constant resulting in an accelerating universe would have been considered non-standard in 1990, but is part of the standard cosmology in 2010.

The Big Bounce hypothesis is a cosmological model for the origin of the known universe. It was originally suggested as a phase of the cyclic model or oscillatory universe interpretation of the Big Bang, where the first cosmological event was the result of the collapse of a previous universe. It receded from serious consideration in the early 1980s after inflation theory emerged as a solution to the horizon problem, which had arisen from advances in observations revealing the large-scale structure of the universe.

A cyclic 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.

In physical cosmology, structure formation is the formation of galaxies, galaxy clusters and larger structures from small early density fluctuations. The universe, as is now known from observations of the cosmic microwave background radiation, began in a hot, dense, nearly uniform state approximately 13.8 billion years ago. However, looking at the night sky today, structures on all scales can be seen, from stars and planets to galaxies. On even larger scales, galaxy clusters and sheet-like structures of galaxies are separated by enormous voids containing few galaxies. Structure formation attempts to model how these structures were formed by gravitational instability of small early ripples in spacetime density or another emergence.

<span class="mw-page-title-main">Paul Steinhardt</span> American theoretical physicist (born 1952)

Paul Joseph Steinhardt is an American theoretical physicist whose principal research is in cosmology and condensed matter physics. He is currently the Albert Einstein Professor in Science at Princeton University, where he is on the faculty of both the Departments of Physics and of Astrophysical Sciences.

<span class="mw-page-title-main">History of the Big Bang theory</span> History of a cosmological theory

The history of the Big Bang theory began with the Big Bang's development from observations and theoretical considerations. Much of the theoretical work in cosmology now involves extensions and refinements to the basic Big Bang model. The theory itself was originally formalised by Father Georges Lemaître in 1927. Hubble's Law of the expansion of the universe provided foundational support for the theory.

The expansion of the universe is the increase in distance between gravitationally unbound parts of the observable universe with time. It is an intrinsic expansion, so it does not mean that the universe expands "into" anything or that space exists "outside" it. To any observer in the universe, it appears that all but the nearest galaxies recede at speeds that are proportional to their distance from the observer, on average. While objects cannot move faster than light, this limitation applies only with respect to local reference frames and does not limit the recession rates of cosmologically distant objects.

In physical cosmology and astronomy, dark energy is an unknown form of energy that affects the universe on the largest scales. Its primary effect is to drive the accelerating expansion of the universe. Assuming that the lambda-CDM model of cosmology is correct, dark energy is the dominant component of the universe, contributing 68% of the total energy in the present-day observable universe while dark matter and ordinary (baryonic) matter contribute 26% and 5%, respectively, and other components such as neutrinos and photons are nearly negligible. Dark energy's density is very low: 6×10−10 J/m3, much less than the density of ordinary matter or dark matter within galaxies. However, it dominates the universe's mass–energy content because it is uniform across space.

Conformal cyclic cosmology (CCC) is a cosmological model in the framework of general relativity and proposed by theoretical physicist Roger Penrose. In CCC, the universe iterates through infinite cycles, with the future timelike infinity of each previous iteration being identified with the Big Bang singularity of the next. Penrose popularized this theory in his 2010 book Cycles of Time: An Extraordinary New View of the Universe.

A black hole cosmology is a cosmological model in which the observable universe is the interior of a black hole. Such models were originally proposed by theoretical physicist Raj Pathria, and concurrently by mathematician I. J. Good.

The initial singularity is a singularity predicted by some models of the Big Bang theory to have existed before the Big Bang. The instant immediately following the initial singularity is part of the Planck epoch, the earliest period of time in the history of our universe.

References

  1. 1 2 "The Nobel Prize in Physics 2011". NobelPrize.org. Retrieved 2020-09-27.
  2. ↑ Falk, Dan (22 June 2020). "This Cosmologist Knows How It's All Going to End". Quanta Magazine. Retrieved 2020-09-27.
  3. ↑ Perlmutter, Saul (April 2003). "Supernovas, Dark Energy, and the Accelerating Universe". Physics Today . 56 (4): 53–60. Bibcode:2003PhT....56d..53P. doi: 10.1063/1.1580050 . ISSN   0031-9228.
  4. 1 2 Sutter, Paul (March 2023). "Dark energy could lead to a second (and third, and fourth) Big Bang, new research suggests". Space.com.
  5. ↑ "Friedmann universe | cosmology | Britannica". www.britannica.com. Retrieved 2022-12-15.
  6. ↑ Mack, Katie (2020). The end of everything (astrophysically speaking). New York. p. 65. ISBN   978-1-9821-0354-5. OCLC   1148167457.{{cite book}}: CS1 maint: location missing publisher (link)
  7. ↑ Rosenthal, Vlad (2011). From the Big Bang to the Big Crunch and Everything in Between A Simplified Look at a Not-So-Simple Universe. iUniverse. p. 194. ISBN   9781462016990.
  8. ↑ McSween, Steve (2015). "Big Crunch Universe - Big Crunch Universe Reconsidering a contracting universe and redshifts". Big Crunch Universe. Retrieved 2022-09-21.
  9. ↑ Wang, Yun; Kratochvil, Jan Michael; Linde, Andrei; Shmakova, Marina (2004). "Current observational constraints on cosmic doomsday". Journal of Cosmology and Astroparticle Physics. 2004 (12): 006. arXiv: Astro-ph/0409264 . Bibcode:2004JCAP...12..006W. doi:10.1088/1475-7516/2004/12/006. S2CID   56436935.
  10. 1 2 "Jennifer Bergman, The Big Crunch, Windows to the Universe (2003)". Archived from the original on 2010-03-16. Retrieved 2009-02-15.
  11. ↑ Croswell, Ken (2001). The universe at midnight : observations illuminating the cosmos. New York: Free Press. ISBN   0-684-85931-9. OCLC   47073310.
  12. ↑ Hoskin, Micheal (1985). "Stukeley's Cosmology and the Newtonian Origin of Olber's Paradox". Cambridge University. 16 (2): 77. Bibcode:1985JHA....16...77H. doi:10.1177/002182868501600201. S2CID   117384709.
  13. ↑ Tertkoff, Ernie. Chodos, Alan; Ouellette, Jennifer (eds.). "Einstein's Biggest Blunder". APS. 14 (7).
  14. ↑ Lemonick, Michael D. "Why Einstein was wrong about being wrong". phys.org. Retrieved 2022-12-16.
  15. ↑ Bunn, E. F. (2009). "The Kinematic Origin of the Cosmological Redshift." American Journal of Physics . 77 (8): 688–694. arXiv:0808.1081. Bibcode:2009AmJPh..77..688B. doi:10.1119/1.3129103. S2CID 1365918.
  16. ↑ "WMAP- Cosmological Constant or Dark Energy". map.gsfc.nasa.gov. Retrieved 2022-12-16.
  17. ↑ Isaacson, Walter (2007). Einstein : his life and universe. New York. ISBN   978-0-7432-6473-0. OCLC   76961150.{{cite book}}: CS1 maint: location missing publisher (link)
  18. ↑ Steinhardt, Paul; Turok, Neil (24 April 2004). "The Cyclic Model Simplified". New Astronomy Reviews. 49 (2–6): 43–57. arXiv: astro-ph/0404480 . Bibcode:2005NewAR..49...43S. doi:10.1016/j.newar.2005.01.003. S2CID   16034194.
  19. ↑ Tolman, Richard C. (1987). Relativity, thermodynamics, and cosmology. New York: Dover Publications. ISBN   0-486-65383-8. OCLC   15365972.
  20. ↑ Woit, Peter (2007). Not even wrong : the failure of string theory and the continuing challenge to unify the laws of physics. London: Vintage. ISBN   978-0-09-948864-4. OCLC   84995224.
  21. ↑ Penrose, Roger. "Cycles of Time: An Extraordinary New View of the Universe [Hardcover]." (2011).
  22. ↑ Jow, Dylan L.; Scott, Douglas (2020-03-09). "Re-evaluating evidence for Hawking points in the CMB". Journal of Cosmology and Astroparticle Physics. 2020 (3): 021. arXiv: 1909.09672 . Bibcode:2020JCAP...03..021J. doi:10.1088/1475-7516/2020/03/021. ISSN   1475-7516. S2CID   202719103.
  23. ↑ "New evidence for cyclic universe claimed by Roger Penrose and colleagues". Physics World. 2018-08-21. Retrieved 2022-12-15.
  24. ↑ Ashtekar, Abhay (30 November 2008). "Loop Quantum Cosmology: An Overview". General Relativity and Gravitation. arXiv: 0812.0177 .
  25. ↑ Singh, Parampreet (14 September 2014). "Loop Quantum Cosmology and the Fate of Cosmological Singularities" (PDF). Department of Physics and Astronomy, Louisiana State University. 42. Baton Rouge, Louisiana 70803, USA: 121. arXiv: 1509.09182 . Bibcode:2014BASI...42..121S.{{cite journal}}: CS1 maint: location (link)
  26. ↑ Yirka, Bob. "Predicting how soon the universe could collapse if dark energy has quintessence". phys.org. Retrieved 14 May 2022.
  27. ↑ "The universe could stop expanding 'remarkably soon', study suggests". livescience.com. 2 May 2022. Retrieved 14 May 2022.
  28. ↑ Andrei, Cosmin; Ijjas, Anna; Steinhardt, Paul J. (12 April 2022). "Rapidly descending dark energy and the end of cosmic expansion". Proceedings of the National Academy of Sciences. 119 (15): e2200539119. arXiv: 2201.07704 . Bibcode:2022PNAS..11900539A. doi: 10.1073/pnas.2200539119 . ISSN   0027-8424. PMC   9169868 . PMID   35380902. S2CID   247476377.
  29. ↑ Davies, Paul (1997). The Last Three Minutes: Conjectures About The Ultimate Fate of the Universe. Basic Books. ISBN   978-0-465-03851-0.
  30. ↑ Douglas Adams. The Restaurant at the End of the Universe.
  31. ↑ "The High-Z SN Search Description".
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.