The long-term future of the universe

1979 ◽  
Vol 23 ◽  
pp. 265-277 ◽  
Author(s):  
Jamal N. Islam
Keyword(s):  
The Universe

scholarly journals COSMIC ACCELERATION AND CONCORDANCE FROM CAUSAL BACKREACTION WITH RECURSIVE NONLINEARITIES

2013 ◽  
Vol 22 (13) ◽  
pp. 1330026 ◽  
Author(s):  
BRETT BOCHNER
Keyword(s):  
Dark Energy ◽  
Large Scale ◽  
Cosmic Acceleration ◽  
Late Time ◽  
Clustering Model ◽  
Hierarchical Nature ◽  
The Universe ◽  
Far Future ◽  
Apparent Acceleration

We review the causal backreaction paradigm, in which the need for Dark Energy is eliminated via the generation of an apparent cosmic acceleration from the causal flow of inhomogeneity information coming in from distant structure-forming regions. The formalism detailed here incorporates the effects of "recursive nonlinearities": the process by which already-established metric perturbations will subsequently act to slow-down all future flows of inhomogeneity information. Despite such effects, we find viable cosmological models in which causal backreaction successfully serves as a replacement for Dark Energy, via the adoption of relatively large values for the dimensionless "strength" of the clustering evolution functions being modeled. These large values are justified by the hierarchical nature of clustering and virialization in the universe, which occurs on multiple cosmic length scales simultaneously; moreover, the clustering model amplitudes needed to match the apparent acceleration can be moderated via the incorporation of a model parameter representing the late-time slow-down of clustering due to astrophysical feedback processes. In summary, an alternative cosmic concordance can be achieved for a matter-only universe in which the apparent acceleration observed is generated entirely by causal backreaction effects. Lastly, considering the long-term fate of the universe, while the possibility of an "eternal" acceleration due to causal backreaction seems unlikely, this conclusion does not take into account the large-scale breakdown of cosmological isotropy in the far future, or the eventual ubiquity of gravitationally-nonlinear perturbations.

Pulsar timing and relativistic gravity

1992 ◽  
Vol 341 (1660) ◽  
pp. 117-134 ◽  
Keyword(s):  
Gravitational Waves ◽  
Binary Systems ◽  
Strong Field ◽  
Low Frequency ◽  
Rate Of Change ◽  
Pulsar Timing ◽  
Basic Physics ◽  
Time Standards ◽  
The Universe

In addition to being fascinating objects to study in their own right, pulsars are exquisite tools for probing a variety of issues in basic physics. Recycled pulsars, thought to have been spun up in previous episodes of mass accretion from orbiting companion stars, are especially well suited for such applications. They are extraordinarily stable clocks, approaching and perhaps exceeding the long-term stabilities of the best terrestrial time standards. Most of them are found in binary systems, with orbital velocities as large as 10 -3 c. They provide unique opportunities for measuring neutron star masses, thereby yielding fundamental astrophysical data difficult to acquire by any other means. And they open the way for high precision tests of the nature of gravity under conditions much more ‘relativistic ’ than found anywhere within the Solar System. Among other results, pulsar timing observations have convincingly established the existence of quadrupolar gravitational waves propagating at the speed of light. They have also placed interesting limits on possible departures of the strong-field nature of gravity from general relativity, on the rate of change of Newton’s constant, G , and on the energy density of low-frequency gravitational waves in the universe.

scholarly journals Landasan Fondasional Integrasi Keilmuan di UIN Maulana Malik Ibrahim Malang dan UIN Sunan Ampel Surabaya

2016 ◽  
Vol 10 (1) ◽  
pp. 248
Author(s):  
Husniyatus Salamah Zainiyati
Keyword(s):  
Higher Education ◽  
Religious Values ◽  
Learning Models ◽  
Intellectual Tradition ◽  
Islamic Studies ◽  
Local Tradition ◽  
The Universe ◽  
Object Of Knowledge

<p>This article deals with the foundational base for integration of sciences trough interdisciplinary Islamic studies, with particular reference to UIN Malang and Surabaya. There are eleven IAINs/STAINs which have been transformed into UIN, each university has their own concept of developing Islamic knowledge. UIN Malang has the concept of pohon ilmu (the tree of sciences) and UIN Surabaya has the concept of integrated twin towers with three pillars. Although different in developing the concept, the two universities share the same perspective of perceiving the relation between general and religious sciences. The integration of science does not refer to the classification of its subject, but rather to the object of knowledge so that religious values can be transformed into different disciplines. It is hoped that in the long term UIN—with the foundation of the Qur’ân and H}adîth—can motivate the emergence of new sciences as blessing for the universe, or at least give new alternatives for the existing sciences, such as Islamic economics. The integration of sciences also needs to be articulated in learning models which are developed while emphasizing harmony between the intellectual tradition of higher education and local tradition of pesantrens.</p>

For Exoplanets, Anything Is Possible

2017 ◽  
Author(s):  
Sara Seager ◽  
Adolfo Plasencia
Keyword(s):  
Young People ◽  
Scientific Interest ◽  
The Universe

Sara Seager, the pioneering astrophysicist, mathematician and planetary scientist reflects in this dialogue about how exoplanets, the purpose of her science, discovered her before she discovered them. She also explains her relationship with mathematics and why for her physics is the most beautiful way to describe the universe, as well as explaining the growing scientific interest to discover planets that orbit a star different to our sun. Later, Sara explains that all astrophysics projects she works on are very long term and is consequently concerned about whether there will be enough young people in this world of immediacy with sufficient patience to become astronomers. She also goes on to explain why life capable of travelling across galaxies will be non biological, as well as discussing how, and with what help, she is facing the greatest challenge of her life: trying to find another Earth, in other words, another planet like Earth with signs of life.

scholarly journals Long-term implications of observing an expanding cosmological civilization

2017 ◽  
Vol 17 (1) ◽  
pp. 87-95 ◽  
Author(s):  
S. Jay Olson
Keyword(s):  
Angular Separation ◽  
Separation Distance ◽  
Speed Limit ◽  
Single Observation ◽  
Cosmic Expansion ◽  
Cosmological Distance ◽  
First Mover Advantage ◽  
Expansion Speed ◽  
The Universe

AbstractSuppose that advanced civilizations, separated by a cosmological distance and time, wish to maximize their access to cosmic resources by rapidly expanding into the universe. How does the presence of one limit the expansionistic ambitions of another, and what sort of boundary forms between their expanding domains? We describe a general scenario for any expansion speed, separation distance and time. We then specialize to a question of particular interest: What are the future prospects for a young and ambitious civilization if they can observe the presence of another at a cosmological distance? We treat cases involving the observation of one or two expanding domains. In the single-observation case, we find that almost any plausible detection will limit one's future cosmic expansion to some extent. Also, practical technological limits to expansion speed (well below the speed of light) play an interesting role. If a domain is visible at the time one embarks on cosmic expansion, higher practical limits to expansion speed are beneficial only up to a certain point. Beyond this point, a higher speed limit means that gains in the ability to expand are more than offset by the first-mover advantage of the observed domain. In the case of two visible domains, it is possible to be ‘trapped’ by them if the practical speed limit is high enough and their angular separation in the sky is large enough, i.e. one's expansion in any direction will terminate at a boundary with the two visible civilizations. Detection at an extreme cosmological distance has surprisingly little mitigating effect on our conclusions.

scholarly journals High precision particle astrophysics as a new window on the universe with an Antimatter Large Acceptance Detector In Orbit (ALADInO)

2021 ◽  
Author(s):  
R. Battiston ◽  
B. Bertucci ◽  
O. Adriani ◽  
G. Ambrosi ◽  
B. Baoudoy ◽  
...  
Keyword(s):  
Cosmic Radiation ◽  
Precise Measurement ◽  
Cosmic Ray ◽  
High Energy ◽  
Indirect Detection ◽  
High Energy Astrophysics ◽  
Large Acceptance ◽  
Scientific Questions ◽  
The Universe

AbstractMultimessenger astrophysics is based on the detection, with the highest possible accuracy, of the cosmic radiation. During the last 20 years, the advent space-borne magnetic spectrometers in space (AMS-01, Pamela, AMS-02), able to measure the charged cosmic radiation separating matter from antimatter, and to provide accurate measurement of the rarest components of Cosmic Rays (CRs) to the highest possible energies, have become possible, together with the ultra-precise measurement of ordinary CRs. These developments started the era of precision Cosmic Ray physics providing access to a rich program of high-energy astrophysics addressing fundamental questions like matter-antimatter asymmetry, indirect detection for Dark Matter and the detailed study of origin, acceleration and propagation of CRs and their interactions with the interstellar medium.In this paper we address the above-mentioned scientific questions, in the context of a second generation, large acceptance, superconducting magnetic spectrometer proposed as mission in the context of the European Space Agency’s Voyage2050 long-term plan: the Antimatter Large Acceptance Detector In Orbit (ALADInO) would extend by about two orders of magnitude in energy and flux sensitivity the separation between charged particles/anti-particles, making it uniquely suited for addressing and potentially solving some of the most puzzling issues of modern cosmology.

scholarly journals Krylov, Gnedich, and the Mythology of Friendship in Gogol’s The Tale of How Ivan Ivanovich Quarreled with Ivan Nikiforovich

Slovene ◽  
2015 ◽  
Vol 4 (2) ◽  
pp. 7-35
Author(s):  
Ekaterina E. Lyamina ◽  
Natalia V. Samover
Keyword(s):  
Everyday Life ◽  
Public Library ◽  
Main Idea ◽  
Real Relationship ◽  
Cultural Myth ◽  
Specific Position ◽  
The Universe

The paper questions the origins of Nikolai Gogol’s The Tale of How Ivan Ivanovich Quarreled with Ivan Nikiforovich (1833) and its specific position in the Mirgorod collection. The authors identify and analyze an important and overlooked level of allusions of the tale—that of the literary everyday life of the Russian capital in 1820s–early 1830s, eagerly observed and “digested” by the young Gogol. The article demonstrates how and why the phenomenon of a long-term friendship between Nikolai Gnedich and Ivan Krylov, two prominent figures of literary St. Petersburg who were poets, librarians, and neighbors, was created by the neo-classical milieu of Alexey Olenin, the director of the Imperial Public Library. It also points out that the harmony of this cultural myth contrasted with the reality of the Gnedich-Krylov relationship (which faded away soon after Gnedich’s retirement and his move to another apartment), a development that was certainly known to Gogol. The main idea of The Tale of How Ivan Ivanovich Quarreled with Ivan Nikiforovich—the sudden break in a great friendship followed by the destruction of the universe in which it flourished—seems to have been influenced by the tension created by the contrast between the men’s real relationship and the myth of their great friendship. The numerous features linking Ivan Ivanovich and Ivan Nikiforovich to Gnedich and Krylov, respectively, are not to be interpreted as a case of a direct prototypicality, however; Gogol’s paired friends-enemies also appear to reflect a development of themes from the Russian folklore bestiary.

scholarly journals Joining efforts to destroy a mighty empire: the Delphic oracle reloaded!

2021 ◽  
Vol 10 (34) ◽  
pp. 1-3
Author(s):  
Carlos Renato Zacharias
Keyword(s):  
Suicide Attempt ◽  
Active Substance ◽  
The World ◽  
Scientific Approach ◽  
Long Time ◽  
High Dilutions ◽  
The Universe

Whether in short or long term, it seems that history always repeats itself! We started in 2011 under the announcement of another collective suicide attempt by organized by Merseyside Skeptics Society, with followers in various cities all over the world! The reasoning behind this movement is quite clear: if homeopathic medicines are highly diluted, then it can not be found one even molecule of the supposed active substance, inside it. Hence the campaign slogan: Homeopathy: there is nothing in it! ... It seems that the story wants to repeat again! If we join efforts to satisfy the skeptics, the prophecy of the Skeptics’ Oracle will be fulfilled: "respect the Avogadro’s limit and we no longer fight against homeopathy”! If we go forward with this fight, we will destroy ourselves, the homeopathy and all science behind the high dilutions, leaving nothing for the skeptics do, unless, quietly to observe our self-destruction! ... If we want to get into a true battle, then we should review and reflect on our scientific approach to the phenomenon of the HD and homeopathy. And we don’t need to bother in requesting a space in the universe of science, because this decision is not entitled to the skeptics. Further, this place is already booked since a long time! We should only be dedicated to the difficult task of uncovering the phenomenon behind the HD and Homeopathy, in order to fill our space in an honorable manner!

scholarly journals The search for life in our Solar System and the implications for science and society

2011 ◽  
Vol 369 (1936) ◽  
pp. 594-606 ◽  
Author(s):  
Christopher P. McKay
Keyword(s):  
Solar System ◽  
Environmental Ethics ◽  
Life Forms ◽  
Tree Of Life ◽  
Science And Society ◽  
The Comparative Study ◽  
Diversity Of Life ◽  
The Universe ◽  
Second Genesis

The search for another type of life in the Solar System addresses the fundamental question of life in the Universe. To determine if life forms we discover represent a second genesis, we must find biological material that would allow us to compare that life to the Earth’s phylogenetic tree of life. An organism would be alien if, and only if, it did not link to our tree of life. In our Solar System, the worlds of interest for a search for life are Mars, Europa, Enceladus and, for biochemistry based on a liquid other than water, Titan. If we find evidence for a second genesis of life, we will certainly learn from the comparative study of the biochemistry, organismal biology and ecology of the alien life. The discovery of alien life, if alive or revivable, will pose fundamentally new questions in environmental ethics. We should plan our exploration strategy such that we conduct biologically reversible exploration. In the long term we would do well, ethically and scientifically, to strive to support any alien life discovered as part of an overall commitment to enhancing the richness and diversity of life in the Universe.

scholarly journals Long-term Research

2011 ◽  
Vol 17 (4) ◽  
pp. 295
Author(s):  
Graham R Fulton
Keyword(s):  
Broad Spectrum ◽  
Field Research ◽  
Bufo Marinus ◽  
Long Time ◽  
The Media ◽  
The Universe

IN earlier issues Broad-Spectrum-Academics’ Essays have covered Cane Toads (Bufo marinus), squirrels, the media and the universe. Rick Shine wrote as a herpetologist and as a leader in ecological field-research while Fred Watson wrote as an astronomer engaging us with rocket science, telescopes and a squirrel living in an Arizonan mountain-top. Both these luminaries have one obvious thing in common with the author in this issue: they have been doing it for a long time.

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