Academic literature on the topic 'Growing block universe'

AbstractThere are many questions we can ask about time, but perhaps the most fundamental is whether there are metaphysically interesting differences between past, present and future events. An eternalist believes in a block universe: past, present and future events are all on an equal footing. A gradualist believes in a growing block: he agrees with the eternalist about the past and the present but not about the future. A presentist believes that what is present has a special status. My first claim is that the familiar ways of articulating these views result in there being no substantive disagreement at all between the three parties. I then show that if we accept the controversial truthmaking principle, we can articulate a substantive disagreement. Finally, I apply this way of formulating the debate to related questions such as the open future and determinism, showing that these do not always line up in quite the way one would expect.

Celem mojego artykułu jest przedstawienie refleksji na temat związku między sposobem istnienia przeszłości (tym, jak wolno ją postrzegać) a podejściem do umierania oraz śmierci. Leżąca u podstaw moich rozważań interpretacja Platońskich słów „μελέτη θανάτου” (Fedon, 81 a) w zestawieniu z Parmenidejskim „τὸ γὰρ αὐτὸ νοεῖν ἐστίν τε καὶ εἶναι” (Περί φύσεως, B3) wydaje się dozwolonym i korzystnym intelektualnie rezultatem spojrzenia na te wyimki w świetle ἄσκησις: filozofii pojmowanej jako sposób rozumnego życia-umierania. Jednym z ważnych przesłań filozofii starożytnej zdaje się pogląd, że to, o czym da się pomyśleć, musi istnieć. Wówczas — jako że myślenie (wspominanie) o tym, co wydarzone, jawi się rzetelniejsze niż przewidywanie tego, co dopiero się zdarzy — należy przydać przeszłości odmienny status ontyczny aniżeli przyszłości. Jeśli zaś sięgnąć, dla przykładu, po współczesną teorię rosnącego wszechświata (C. D. Broad; growing [block] universe theory), wtedy wolno — być może — uznać czyjąś śmierć za kolejną warstwę jego istnienia, nie destruującą warstw poprzednich. Pozwala to zmienić postrzeganie przyszłego bądź aktualnego „braku” osoby zmarłej, jak i nieuniknionego zbliżania się (do) śmierci.

AbstractWe use data from large surveys of the local universe (SDSS+Galaxy Zoo) to show that the galaxy–black hole connection is linked to host morphology at a fundamental level. The fraction of early-type galaxies with actively growing black holes, and therefore the AGN duty cycle, declines significantly with increasing black hole mass. Late-type galaxies exhibit the opposite trend: the fraction of actively growing black holes increases with black hole mass.

AbstractWe discuss a numerical model for black hole (BH) growth and feedback that allows simultaneous tracking of the evolution of galaxies and their central BHs in fully cosmological simulations. After describing the main features of the numerical model adopted, we show how BHs in these simulations affect the properties of their host halos and how this in turn impacts the growth of the BHs themselves. We also present results from a set of simulations specifically designed to address the issue of BH assembly in the early Universe and discuss whether or not different extensions of the model, in particular rapidly spinning BHs and gravitational recoils, can hamper the formation of the first bright quasars.

The origin of super-massive black holes in the early universe remains poorly understood. Gravitational collapse of a massive primordial gas cloud is a promising initial process, but theoretical studies have difficulty growing the black hole fast enough. We report numerical simulations of early black hole formation starting from realistic cosmological conditions. Supersonic gas motions left over from the Big Bang prevent early gas cloud formation until rapid gas condensation is triggered in a protogalactic halo. A protostar is formed in the dense, turbulent gas cloud, and it grows by sporadic mass accretion until it acquires 34,000 solar masses. The massive star ends its life with a catastrophic collapse to leave a black hole—a promising seed for the formation of a monstrous black hole.

The current monetary system has many issues associated with it like double spending, standard transaction fees, financial crisis, centralized power and private ledgers. Blockchain provides a remedy to all these ills by its basic structure, zero or minimal transaction fees and by providing a public ledger system which is visible to everyone who is the part of blockchain which makes it free from complications like double spending and financial crisis. Blockchain is basically a continuously growing list of records or public distributed ledger system called blocks linked and secured suing cryptography. Each block has multiple transaction details associated with it. It was introduced in the year 2009 by Satoshi Nakamoto, who is believed to be a Japanese man, born in 1974. Given the features and universal nature of the Blockchain, which include decentralized ledger system, proof of work and cryptography, one can appreciate that its implementation could result in far reaching changes in all domains.

There is growing notion that black holes may not contain curvature singularities (and that indeed nature in general may abhor such spacetime defects). This notion could have implications on our understanding of the evolution of primordial Black holes (PBHs) and possibly on their contribution to cosmic energy. This paper discusses the evolution of a nonsingular black hole (NSBH) based on a recent model [M. R. Mbonye and D. Kazanas, Phys. Rev. D. 72 (2005) 024016]. The model is used to discuss the time evolution of a primordial black hole (PBH), through the early radiation era of the universe to present, under the assumption that PBHs are nonsingular. In particular, we track the evolution of two benchmark PBHs, namely the one radiating up to the end of the cosmic radiation domination era, and the one stopping to radiate currently, and in each case determine some useful features including the initial mass mf and the corresponding time of formation tf. It is found that along the evolutionary history of the universe the distribution of PBH remnant masses (PBH-RM) PBH-RMs follows a power law. We believe such a result can be a useful step in a study to establish current abundance of PBH-MRs.

This research identifies the way the science of time travel is presented to the public through the medium of feature films, and discovers if this can be used to construct a comprehensive set of models about time travel and its consequences. There is no universally accepted understanding of what constitutes the nature of time. Even though the fundamental laws of physics do not prohibit time travel, scientists and philosophers do not agree about what would happen if backwards time travel ever became a reality. I identified models that scientists and philosophers have produced about the nature of time, time travel and other temporal phenomena. I then determined the model of time used in each of the 100 time travel films that I reviewed. I also used a verbal survey to elicit the personal models of time travel for each participant of three focus groups I conducted with members of the movie-going public. I compared these models of time with the personal models used by members of the movie-going public and synthesised them to develop a comprehensive set of 21 models of time. The "guyline" diagrams that I devised proved to be a very useful tool for analysing how the timelines of the time travellers behaved in each film. My research has shown that an investigation of time travel in films can indeed be used to construct useful models of time based on the evidence of the 21 models that I developed. Furthermore, I showed that both my models of time travel and my guyline diagrams helped to structure conversations about time with members of the movie-going public. The findings of this thesis can be used by scientists, philosophers, filmmakers and the public to help them clarify our thinking about time travel, the nature of time, how it is communicated, and also in future research.

This chapter examines the problem of time with regard to the unification of general relativity and quantum mechanics and advances in broad outline one direction that this unification might potentially follow, namely, a version of Broad’s growing block universe consistent with Whitehead’s late metaphysics and relativistic quantum field theory. The theories of time – eternalism, presentism and the growing block theory – are discussed in connection with three and four dimensional views of reality.

Chapter 2 identifies a distinct uptick in northern Black support for separate schools. The rise of scientific racism fueled anti-Black discrimination that accelerated alongside the first Great Migration and the Great Depression. Hostile whites segregated classrooms and buildings in defiance of state law as Black populations increased. At the same time, there is compelling evidence from New Jersey, New York, Ohio, Indiana, Illinois, and Michigan that Black families either passively accepted or actively requested separate classrooms and schools in order to access Black teachers. Many Black northerners believed separate schools would offer a higher quality education and more of the teaching and administrative jobs that sustained the Black middle class. Still, this position was far from universal, and many northern Black communities energetically resisted school segregation. A growing number of Black intellectuals and civil rights activists vehemently objected to any form of state-sponsored segregation and campaigned actively for school integration.

Challenges involved in space communications across wireless channels call for new approaches to radio systems. Due to the growing need for frequency change in modern wireless systems, an adaptive radio system has the highest demand. Software-defined radios (SDR) offer this type of adaptivity as well as compatibility with other standard platforms such as USRP/GNU radio. Despite limitations of this approach due to hardware components, viable modeling and simulation as well as deployable systems are possible using this platform. This chapter presents a detailed implementation procedure for a USRP/GNU radio-based SDR communication system that can be used for practical experiments as well as an academic lab in this field. In this experiment the USRP has been configured to receive signal from a local radio station using the BasicRX model daughterboard. The programmable USRP executes Python block code implemented in the GNU Radio Companion (GRC) on Ubuntu OS.

This chapter explores how the growing awareness of the global dimensions of development had made international organizations, especially the United Nations, crucial to development thinking and practice. International organizations' involvement in development proceeded in stages, converging toward “one size fits all,” universal technocratic knowledge, and solutions unconnected to cultural specificities, even if distinctive in their ideological orientation. In the 1990s, the naturalized French diplomat Stéphane Hessel wrote that development was a concept that informed the whole structure of the United Nations and gave it meaning. He claimed it took forty years to move from the black-and-white reasoning of the 1950s toward a more nuanced view. The chapter tells the story of this transformation. International organizations that had acted as agencies of civilization in late colonial times became arenas in which different ideas of modernity were articulated. Some, like the World Bank, were clearly the expression of a Western capitalist mindset, whereas others, like the United Nations, provided a home for both technocratic thinking and anti-imperialist ideas that differed from the prevailing modernization theory.

The survival of the Underground after 1989 rests on the collective memory it has shaped in relation to establishments. This relational pair is the convention that holds the Underground together: the pathway of underground-establishment is continuous, the communist era being articulated into the multi-temporal meaning and use of establishment. This chapter addresses the nature of transformation in the Underground after 1989—although the ecology embraces change and technology, the musical material remains the same. The Plastic People of the Universe have now become the oft-quoted rock group of the Czech Underground, symbolizing Eastern bloc communist oppression, Cold War logics of liberty and freedom, and music’s borderless humanity. The Plastics maintain this legacy in local and foreign discourse while performing repertoire from their forty-five years of ensemble history. Yet the chapter also points to how new musical practices and meanings have grown in the Merry Ghetto, suggesting an Underground Renaissance. The contemporary Underground festival U Skaláka functions as an environment to reaffirm these articulations between musicking and forms of freedom, politics and historical identity. Continuing to play and to listen to Underground music nowadays provides conditions for Undergrounders to continue living within their cultural ecology and thus helps us to understand self-reflexive notions of the political during communism as not ending with 1989 but rather adapting to different forms of creative and political suppression in contemporary times.

From the nation’s founding inclusion in and exclusion from the U.S. body politic has been racialized. Citizenship and whiteness have been defined in opposition to slavery and blackness, the free white man celebrated as the prototype of the liberty-loving American citizen. “The very structure of American citizenship is white,” political philosophers and historians repeatedly tell us. Yet U.S. democracy took form during one of the most radical periods of human history, the Age of Revolution when the political world appeared remade and the promise of freedom unlimited. Between the 1780s and the War of 1812, increasingly radical political movements crisscrossed the Atlantic challenging absolute monarchies, establishing post-colonial republics and questioning the legitimacy of human slavery. Born of such momentous times, how were U.S. citizenship and democracy constituted as powerful instruments of racial exclusion? How were the majority of US citizens and their political leaders able to reconcile their commitment to the equality of all men with the centuries-old practice of chattel slavery? This essay ponders that conundrum through an exploration of a rapidly growing literary genre, the Barbary captivity narratives, cheaply printed popular accounts of the seizure and enslavement of American sailors by Barbary “pirates.” Focusing on the period between the 1780s and the War of 1812, that epic time when revolutionary fervor — and most especially the Haitian Revolution — made the contradictory interplay of Atlantic slavery and universal rights impossible to ignore, this article will explore the role popular representations of white and black enslavement played in the construction of the new U.S. republic and U.S. citizenship.

Modularity, like the responsiveness that gives rise to it during development and evolution, is a universal property of living things and a fundamental determinant of how they evolve. Modularity refers to the properties of discreteness and dissociability among parts and integration within parts. There are many other words for the same thing, such as atomization (Wagner, 1995), individualization (Larson and Losos, 1996), autonomy (Nijhout, 1991b), dislocation (Schwanwitsch, 1924), decomposability (Wimsatt, 1981), discontinuity (Alberch, 1982), gene nets (Bonner, 1988), subunit organization (West-Eberhard, 1992a, 1996), compartments or compartmentation (Garcia-Bellido et al., 1979; Zuckerkandl, 1994; Maynard-Smith and Szathmary, 1995; Kirschner and Gerhart, 1998), and compartmentalization (Gerhart and Kirschner, 1997). One purpose of this chapter is to give consistent operational meaning to the concept of modularity in organisms. Seger and Stubblefield (1996, p. 118) note that organisms show “natural planes of cleavage” among organ systems, biochemical pathways, life stages, and behaviors that allow independent selection of different ones. They ask, “What determines where these planes of cleavage are located” and suggest that a “theory of organic articulations” may give insight into the laws of correlation, without specifying what the laws of articulation may be. Wagner (1995, p. 282) recognizes the importance of modularity and proposes a “building block” concept of homology where structural units often correspond to units of function, but concludes (after Rosenberg, 1985) that “there exists no way to distinguish an adequate from an inadequate atomization of the organisms.” Here I propose that modularity has a specific developmental basis (see also West-Eberhard, 1989, 1992a, 1996; see also Larson and Losos, 1996). Modular traits are subunits of the phenotype that are determined by the switches or decision points that organize development, whether of morphology, physiology, or behavior. Development can be seen as a branching series of decision points, including those caused by physical borders such as membranes or contact zones of growing or diffusing parts (e.g., see Meinhardt, 1982; see also chapter 5, on development). Each decision point demarcates the expression or use of a trait—a modular set—and subordinate branches demarcate lower level modular subunits, producing modular sets within modular sets.

This final chapter opens with Toussaint Louverture in Santo Domingo in 1802, preoccupied with the possibility of a new French invasion. In February, General Leclerc invaded Cape Haitian in the north; Toussaint was captured by French troops and taken to France as prisoner. Although his demise occurred for various reasons, most problematic are the tactics he embraced during the period of 1793-1799, wherein he neglected the interests of the former enslaved people and instead allied himself with the upper class and military interests. The rallying cry of “freedom for all” for the population of the former French colony did not imply that formerly enslaved masses could enjoy autonomy or freely cultivate edible crops on their own properties. While not all rebel leaders fit into the same social category, they did have different interests than the former slaves. Trouillot reminds readers that a true revolution produces profound social changes, inverting the old social order; and thus formerly-enslaved people should have all become property owners. However, the competing revolutionary leaders (including Rigaud, Beauvais, and Toussaint) stunted this possibility, neglecting the needs of the poor majority. It was chiefly the economic aspect of independence that divided Toussaint from the masses. After taking control of the former colony, Toussaint imposed import and export taxes that benefited European countries and the United States instead of Haitians; U.S.-built warehouses popped up on the capital’s wharf, and Saint-Domingue remained economically dependent. The former slaves benefited in no way from growing the sugar, coffee or cotton that they were required to produce during Toussaint’s reign; they were punished for planting food crops. Worse still, Toussaint required that the ex-slaves “respect” the integrity of former plantations by staying and working on them, while he distributed free land to rebel officers. The idea of “freedom” thus lost its resonance amongst the masses. Although members of the State of Saint-Domingue and the ruling class gained economically, it was at the expense of the former enslaved workers. From this point, the behavior of the Haitian State was that of sitting heavily upon the new nation, since their economic and political interests were at odds with one another. A host of contradictions emerged: Dependence/ Independence, Plantations/Small Farms, Commodity/Food crops, White/Black, Mulatto/Black, Mulatto/White, Catholic/Vodou, and French/Creole. Although the Constitution of 1801 abolished slavery and supposedly “guaranteed freedom” to all, it reinforced these fundamental contradictions. The “Moyse Affair” in late 1801 illustrates Trouillot’s understanding of Toussaint’s betrayal of the Haitian people. Moyse, Toussaint’s adopted nephew, had populist political ideas that attracted the black masses. Fearing his potentially subversive ambitions, Toussaint had Moyse judged by a military commission that included Christophe, Vernet, and Pageaux. Moyse was condemned to death and executed, effectively crushing the interests of the masses. Throughout the Revolution Toussaint maintained power by crafting coalitions amongst a wide variety of social classes and competing interests. The dominance of the new military class was a social contradiction that had to be masked, and Toussaint’s actions showed a will to conceal it. Aspects of this problematic behavior and ideology have reappeared in Haiti under Dessalines, Christophe, Salomon, Estimé, Duvalier and others. Official discourse is grounded in several central notions that are easily manipulated by Haitian leaders: first, the notion of “family,” allowing the concealed dominance of one group and the privileging the organized Catholic religion; second, the idea that Haitians should “respect property”; and, the myth of nèg kapab (“capable people”) who possess an inherent right to govern and oppress the people. The political concept of “family,” common throughout Africa and countries with African descendants, was employed by Toussaint as a form of social control: throughout the revolution Toussaint refers to the new Haitian society as a family in order to advance his own “paternal” political objectives and conceal its many contradictions. The state—which his ideology came to epitomize—began to take advantage of the people; it was akin to a vèvè, a matrix holding society together, and a Gordian knot, where complex and twisted socio-economic contradictions favoring a certain class were inscribed. Although Toussaint was kidnapped by the invasion of Leclerc in 1802, this motivated the Haitian masses to stand up and fight for independence from France, which ultimately led to freedom. Thus, living up to the surname of “Louverture” that was given him, Toussaint indeed opened the barrier to independence and warrants appreciation for that. When one revisits the ideology of Toussaint Louverture, and concurrently that of the state of Saint-Domingue, one must not forget that, in spite of all its weaknesses, libèté jénéral (“freedom for all”, or “universal freedom” in today’s terms) was originally a powerful unifying factor, which merits recognition: it helped Toussaint’s troops defeat the British, crush Hédouville, etc. Toussaint was betrayed by plantation owners and French and American commissioners alike, and he always maintained some faith in France, even if the masses did not. Trouillot implies that Toussaint understood the direction in which he wanted to go, but he got lost on the way. To his credit, Toussaint’s experience demonstrated that liberty without political independence was a senseless notion, and others (such as Dessalines) were able to break with his approach and capitalize on this lesson. The book closes with Grinn Prominnin declaring that he is exhausted and that everyone must return to discuss the situation tomorrow to reach a conclusion. The scene remains peaceful, the people complacent. Trouillot suggests that, more than 170 years after the revolution, the task of bringing about real social change in Haiti—and seeing the ambitions of the Revolution fulfilled—remains starkly inert. Readers easily infer that Haiti’s stagnant socio-economic and political situation (in 1977) is due not only to the as yet unfulfilled promises of the Revolution and War for Independence, but also to the escalating damages wreaked upon the Haitian nation by the Duvalier regime and its manipulative cronyism coupled with its totalitarian indigenist ideology.