This essay is focused on the questions of and responsibility for where, when, how and why communication and meetings through archaeology should take place. I have critically studied Swedish public archaeology through three diverse archaeological excava­tions, one took place in the end of the 1980s, and two others in 2012. I have asked for under what circum­stances and with which goals the public efforts become possible. I have inter­viewed leaders for the archaeological excavations and/or the public efforts and questi­o­ned how and why they reached out to the public. I also searched for results and effects in order to problematize and value the public activities. Through interpretation of the resear­ched material it becomes clear that economic issues as well as archaeo­logists interests and engagements are of vital importance for public archaeology. Co-operation in the local community and archaeological documentation is crucial for the deve­lopment of archaeology and its role in society. Keywords: Public archaeology, Community archaeology, Heritage, Communication, Manage­ment, Historic environment education, Time Travel, Living history / I denna uppsats ligger fokus på frågor som berör ansvaret för var, när, hur och varför kommunikation och möten genom arkeologin ska utföras. Med ett kritiskt förhållningssätt har jag studerat svensk publik arkeologi genom tre skilda arkeologiska utgrävningar, en utfördes i slutet på 1980-talet, och två andra år 2012. Jag har undersökt under vilka förutsättningar och med vilka mål de publika insatserna blivit möjliga. Jag har intervjuat ledare för de arkeologiska utgrävningarna och/eller publika insatserna och ställt frågor om hur och varför den publika arkeologin nått ut. Jag har även sökt efter resultat och effekter i syfte att problematisera och värdera den publika verksamheten. Genom min analys av det utforskade materialet står det klart att ekonomi så väl som arkeologers intresse och engagemang är avgörande för publik arkeologi. Samarbeten inom det lokala samhället och arkeologisk dokumentation är ytterst viktigt för utvecklingen av arkeologin och dess roll i samhället.

Thesis (M. Phil.)--University of Queensland, 2002. / Includes bibliographical references.

No description available.

Die vorliegende Arbeit erörtert Ansätze für „Zeitmaschinen“, die in Einklang mit der modernen Physik stehen. Besprochen werden u. a. die Tachyonen-Hypothese, Tiplers rotierender Zylinder, der Gödel-Kosmos, der Anti-de-Sitter-Kosmos und die sogenannten „Wurmlöcher“. Zugleich sollen Ansätze vorgestellt werden (z. B. Eternalismus, Viele-Welten-Modell, Prinzip der konsistenten Geschichte), die Lösungsversuche für die Paradoxien von Vergangenheitsreisen bieten. Obwohl erstaunlicherweise die fundamentalen Gesetze der Physik (abgesehen von extrem seltenen und makroskopisch nicht in Erscheinung tretenden quantenmechanischen Effekten) bei einer Zeitumkehr nicht verletzt sind, scheint es in der Natur doch ein grundsätzliches Verbot von Vergangenheitsreisen zu geben. Der Physiker Dieter Zeh, dessen Position im Schlusskapitel der Arbeit näher beleuchtet wird, vertritt die Auffassung, dass die Science-Fiction-Literatur zum Thema „Zeitreisen“ überwiegend auf einfachen begrifflichen Fehlern beruhe. Die in Anlehnung an die Allgemeine Relativitätstheorie konstruierten Vorgänge seien bestenfalls genauso „theoretisch möglich“ wie ein Gas, das sich von selbst in einer Ecke des Gefäßes versammelt. Um die Reisen in die Vergangenheit scheint es zu stehen wie mit einer Anfrage an Radio Jerewan; die Antwort lautet stets: „Im Prinzip ja, aber …“ Doch die Faszination dieser Idee wird weiterhin Stoff für die „Fiction“ liefern.

Die vorliegende Arbeit erörtert Ansätze für „Zeitmaschinen“, die in Einklang mit der modernen Physik stehen. Besprochen werden u. a. die Tachyonen-Hypothese, Tiplers rotierender Zylinder, der Gödel-Kosmos, der Anti-de-Sitter-Kosmos und die sogenannten „Wurmlöcher“. Zugleich sollen Ansätze vorgestellt werden (z. B. Eternalismus, Viele-Welten-Modell, Prinzip der konsistenten Geschichte), die Lösungsversuche für die Paradoxien von Vergangenheitsreisen bieten. Obwohl erstaunlicherweise die fundamentalen Gesetze der Physik (abgesehen von extrem seltenen und makroskopisch nicht in Erscheinung tretenden quantenmechanischen Effekten) bei einer Zeitumkehr nicht verletzt sind, scheint es in der Natur doch ein grundsätzliches Verbot von Vergangenheitsreisen zu geben. Der Physiker Dieter Zeh, dessen Position im Schlusskapitel der Arbeit näher beleuchtet wird, vertritt die Auffassung, dass die Science-Fiction-Literatur zum Thema „Zeitreisen“ überwiegend auf einfachen begrifflichen Fehlern beruhe. Die in Anlehnung an die Allgemeine Relativitätstheorie konstruierten Vorgänge seien bestenfalls genauso „theoretisch möglich“ wie ein Gas, das sich von selbst in einer Ecke des Gefäßes versammelt. Um die Reisen in die Vergangenheit scheint es zu stehen wie mit einer Anfrage an Radio Jerewan; die Antwort lautet stets: „Im Prinzip ja, aber …“ Doch die Faszination dieser Idee wird weiterhin Stoff für die „Fiction“ liefern.

In this thesis properties of the G&ouml / del spacetime are analyzed and it is explicitly shown that there exist closed timelike curves in this spacetime. Geodesic motions for massive particles and light rays are investigated. One observes the focusing effect as a result of the solution of the geodesic equations. The time it takes for a free particle released from a point to come back to its starting point is calculated. A geometrical interpretation of the G&ouml / del spacetime is given and the question of what the G&ouml / del spacetime looks like is answered.

<p>This project argues that the nuclear bomb has made speculation an integral part of representing the material world. The bomb’s capability to cause an unprecedented extent of destruction and the constant state of latent war between nuclear-armed countries (expressed through arms race and high alert readiness) created a reality where the disasters in the future must be constantly speculated to understand the contemporary world’s material state. The tens of thousands of nuclear warheads sleeping in silos and submarines are not just the sum of their material components, but also incredibly compressed embodiments of future disasters that may be released at a moment’s notice. Regardless of the likelihood of nuclear conflicts (with which this dissertation is not concerned), the weapon exerts its influence as one of the most catastrophic possibilities even as it remains dormant. In considering the implications of nuclear weapons, all nations and people on the planet think not of what they are, but what they can do. The weapon’s possible future states define its present significance.</p><p> The inherent oxymoron of the nuclear bomb is thus that despite its staggering materiality, it is fiction as well. Any representation of the bomb that ponders its sole purpose—mass destruction—is inevitably speculative. While the degrees in which they reference empirical data vary, the narratives from which people around the world from heads of nations to common citizens learn anything at all about nuclear weaponry are forms of fiction, ranging from fantastical literary fictions to strategic fictions attempting to represent the power of the weapon that is itself fantastical. Not all representations of the weapon or nuclear war are, of course, taken seriously. Apocalyptic nuclear events are often used in popular nuclear fictions as a convenient excuse for dismantling the existing social structures and providing interesting backdrops for survivalist stories. The very fact that imaginations of hypothetical nuclear disasters have become an overused cliché all the while proliferation remains an active threat, however, also indicates that the world has been living with the horrifying prospect of nuclear disasters for decades without an actual event of the kind—that, in other words, the weapon has existed mostly as a fiction. The introduction of the nuclear bomb to the world in this sense marks a critical point in history beyond which the speculated future outcomes of the productions in the present increasingly becomes an integral part of understanding the latter.</p><p>The central concept with which I articulate the relationship between the present and the future created by nuclear weaponry is “eventuality.” Eventuality is a narrativization process through which a historical event develops into an anticipated future event as the original event’s outcome. A story about a fictional World War III involving nuclear weapons, for example, is a form of eventuality. The conceptual usefulness of eventuality is that it articulates the historical trend in the post-1945 era as well as the more recent years of climate change, in which hypothetical future events are increasingly represented not just for the purpose of knowing the future itself, but also reassessing the history to date. Eventuality establishes a causal relation between an event and its hypothetical future outcome—or its “eventual” as I call it. By drawing a line of synthetic history extending beyond the present, eventuality as a narrativization process defines the direction in which history has been heading up to the present. Compared to the postmodernist understanding of the representation of the past, eventuality is concerned with how human productions in the present already creates the future and, consequently, how the very ways in which we conceive the present is influenced by the possible futures.</p><p>To discuss the concept of eventuality in detail, the first chapter examines time travel narratives as ideal instances of eventuality. Eventuality consists in two operations running in opposite temporal directions—speculatively writing the future (prospection) and assessing history in light of that speculated future (retrospection). The literary genre that embodies this exact pair of movements is the time travel narrative. H. G. Wells’s novel <i>The Time Machine </i>(1895), the first scientific time travel story, creates a critical legacy for the genre: the assumption that the entirety of time already exists. The conceptualization of the already-existing future is important because it emphasizes the causal relation between the present and the future—the future which the time traveler witnesses is the direct outcome of his present. In the movie adaptation produced during the Cold War, the dystopian course of history is rewritten to be a nuclear war narrative, which suggests that the time travel narrative as a base frame has been appropriated by the desire to speculate the future born with the nuclear bomb. Then decades later the <i>Terminator </i>movies develop the time travel narrative as an instance of eventuality even further by creating a scenario in which the future is no longer just an uncharted territory to be explored, but an active force that has a direct sway over the present’s world. </p><p>Along with literary fictions of nuclear disasters, strategic studies on nuclear conflicts also attempt to represent the nonexistent events of future disasters. The historical significance of the advent of wargaming, a major form of nuclear strategic fiction, is that even the comparatively scientific and empirical study of nuclear war funded by the U.S. military is fundamentally speculative. The very formation and development of wargaming, in other words, is an indication that the nuclear weapon brings with it unknown possibilities for the future. The legitimacy of a wargame’s findings is dependent on that of the future projection used in the scenario. But since the latter is itself speculative and thus cannot be proven, the narrative logic of a wargame is circular or self-referential. This circularity is exactly the structure of the synthetic history in the <i>Terminator </i>films, which is a form of eventuality in which the present creates the future and the future retrospectively redefines the present.</p><p>The nuclear bomb, finally, also contributed to the advent of ecological worldview with its ecocidal nature and sheer extent of destructive capability. Geosciences in the U.S. experienced a rapid growth following the second World War, as the military pursued global surveillance for nuclear activities. Some of the same scientists who developed the weapons also began to study the interactions between radiation and the human body, as the workers in the weapons production lines began to experience radiation sickness. This kind of research was soon expanded to the study of radiation’s ecological effects on a broader scale involving not just the human bodies but also other environmental entities, organic and inorganic. Civilian research projects, in the meantime, found a widespread impact of weapons tests, including the “bone seeker” radioisotopes accumulated in the human body. Lastly, in terms of the more general way of understanding the world, the cases of radiation exposures discovered far away from the sources offered people around the world points of reference with which they could conceive an ecologically interconnected network on a planetary scale. </p>

Das Verfahren der akustischen Laufzeittomographie nutzt die Abhängigkeit der Schallgeschwindigkeit von den Parametern Temperatur und Strömung entlang des Ausbreitungsweges akustischer Signale, um diese Parameter zu bestimmen. Es wird ein Algorithmus vorgestellt, der eine tomographische Rekonstruktion der 2-dimensionalen Strömungsfelder innerhalb eines Messgebietes erlaubt, wobei die räumliche Auflösung des Vektorfeldes der Auflösung des Temperaturfeldes entspricht. Neben Ergebnissen von Simulationen verschiedener Strömungssituationen wird eine Anwendung vorgestellt, welches die Anwendbarkeit des Verfahrens zur Detektion von Strömungs- und Temperaturverteilung in einem abgeschlossenen Raum demonstriert. / Acoustic travel time tomography uses the dependency of sound speed from temperature and flow properties along the propagation path to measure these parameters. An algorithm is introduced which is capable of resolving the two-dimensional flow field within a certain measuring area comparable to the resolution of the temperature field. Different flow fields have been simulated in order to show the reconstruction properties of the algorithm. Furthermore an experiment has been carried out, which demonstrates the applicability of the acoustic tomographic method to detect temperature and flow fields indoor.

A scenario in which modern machine learning models are trained is to make use of past data to be able to make predictions about the future. When working with multiple structured and time-labeled datasets, it has become a more common practice to make use of a join operator called the Point-in-Time join, or PIT join, to construct these datasets. The PIT join matches entries from the left dataset with entries of the right dataset where the matched entry is the row whose recorded event time is the closest to the left row’s timestamp, out of all the right entries whose event time occurred before or at the same time of the left event time. This feature has long only been a part of time series data processing tools but has recently received a new wave of attention due to the rise of the popularity of feature stores. To be able to perform such an operation when dealing with a large amount of data, data engineers commonly turn to large-scale data processing tools, such as Apache Spark. However, Spark does not have a native implementation when performing these joins and there has not been a clear consensus by the community on how this should be achieved. This, along with previous implementations of the PIT join, raises the question: ”How to perform fast and resource efficient Pointin- Time joins in Apache Spark?”. To answer this question, three different algorithms have been developed and compared for performing a PIT join in Spark in terms of resource consumption and execution time. These algorithms were benchmarked using generated datasets using varying physical partitions and sorting structures. Furthermore, the scalability of the algorithms was tested by running the algorithms on Apache Spark clusters of varying sizes. The results received from the benchmarks showed that the best measurements were achieved by performing the join using Early Stop Sort-Merge Join, a modified version of the regular Sort-Merge Join native to Spark. The best performing datasets were the datasets that were sorted by timestamp and primary key, ascending or descending, using a suitable number of physical partitions. Using this new information gathered by this project, data engineers have been provided with general guidelines to optimize their data processing pipelines to be able to perform more resource-efficient and faster PIT joins. / Ett vanligt scenario för maskininlärning är att träna modeller på tidigare observerad data för att för att ge förutsägelser om framtiden. När man jobbar med ett flertal strukturerade och tidsmärkta dataset har det blivit vanligare att använda sig av en join-operator som kallas Point-in-Time join, eller PIT join, för att konstruera dessa datauppsättningar. En PIT join matchar rader från det vänstra datasetet med rader i det högra datasetet där den matchade raden är den raden vars registrerade händelsetid är närmaste den vänstra raden händelsetid, av alla rader i det högra datasetet vars händelsetid inträffade före eller samtidigt som den vänstra händelsetiden. Denna funktionalitet har länge bara varit en del av datahanteringsverktyg för tidsbaserad data, men har nyligen fått en ökat popularitet på grund av det ökande intresset för feature stores. För att kunna utföra en sådan operation vid hantering av stora mängder data vänder sig data engineers vanligvis till storskaliga databehandlingsverktyg, såsom Apache Spark. Spark har dock ingen inbyggd implementation för denna join-operation, och det finns inte ett tydligt konsensus från Spark-rörelsen om hur det ska uppnås. Detta, tillsammans med de tidigare implementationerna av PIT joins, väcker frågan: ”Vad är det mest effektiva sättet att utföra en PIT join i Apache Spark?”. För att svara på denna fråga har tre olika algoritmer utvecklats och jämförts med hänsyn till resursförbrukning och exekveringstid. För att jämföra algoritmerna, exekverades de på genererade datauppsättningar med olika fysiska partitioner och sorteringstrukturer. Dessutom testades skalbarheten av algoritmerna genom att köra de på Spark-kluster av varierande storlek. Resultaten visade att de bästa mätvärdena uppnåddes genom att utföra operationen med algoritmen early stop sort-merge join, en modifierad version av den vanliga sort-merge join som är inbyggd i Spark, med en datauppsättning som är sorterad på tidsstämpel och primärnyckel, antingen stigande eller fallande. Fysisk partitionering av data kunde även ge bättre resultat, men det optimala antal fysiska partitioner kan variera beroende på datan i sig. Med hjälp av denna nya information som samlats in av detta projekt har data engineers försetts med allmänna riktlinjer för att optimera sina databehandlings-pipelines för att kunna utföra mer resurseffektiva och snabbare PIT joins

Zeitreisen und Reisen mit Überlichtgeschwindigkeit sind zwei Menschheitsträume; sie beflügeln die Fantasie und bieten Stoff für skurrile Geschichten. Eine Arbeit zum Thema „Zeitreisen und Reisen mit Überlichtgeschwindigkeit“ zwingt zu einer Auseinandersetzung mit dem Begriff der „Zeit“. Die Vielschichtigkeit und der antinomische Charakter dieses Begriffes machen es schwer, „Zeit“ genauer zu fassen. Zeit tritt uns entgegen als Form der Wahrnehmung in ihrer zutiefst subjektiven Seite, als biologischer Rhythmus, als soziales Phänomen im Sinne einer kollektiven Zeitbestimmung, aber eben auch als physikalischer Parameter. Einsteins Relativitätstheorie revolutioniert unsere Vorstellungen von Raum und Zeit, indem sie sich vom newton-mechanischen Konzept des absoluten Raumes und der absoluten Zeit löst. Sie macht aber das, was bei Wells zehn Jahre vorher noch reine Fiktion war, zu einem für die Physik diskussionswürdigen Thema, nämlich das „Problem der Zeitreisen“. Einsteins Spezielle Relativitätstheorie (1905) erlaubt durch den von ihr vorhergesagten Effekt der Zeitdilatation „Reisen in die Zukunft“, und die Einstein’sche Gravitationstheorie lässt geschlossene zeitartige Linien als Lösungen ihrer Gleichungen zu (z. B. Gödel-Kosmos, Anti-de-Sitter-Kosmos). Allerdings würde eine Reise auf einer Zeitschleife sofort ein ganzes Bündel von Paradoxien (z. B. Großvater-Paradoxon, Informationsparadoxon) und semantischen Inkonsistenzen nach sich ziehen. Obwohl erstaunlicherweise die fundamentalen Gesetze der Physik (abgesehen von extrem seltenen und makroskopisch nicht in Erscheinung tretenden quantenmechanischen Effekten) bei einer Zeitumkehr nicht verletzt würden, scheint es in der Natur doch ein grundsätzliches Verbot von Vergangenheitsreisen zu geben. Der Physiker Dieter Zeh, dessen Position im Schlusskapitel der Arbeit näher beleuchtet wird, vertritt die Auffassung, dass die Science-Fiction-Literatur zum Thema „Zeitreisen“ überwiegend auf einfachen begrifflichen Fehlern beruhe. Die in Anlehnung an die Allgemeine Relativitätstheorie konstruierten Vorgänge seien bestenfalls genauso „theoretisch möglich“ wie ein Gas, das sich von selbst in einer Ecke des Gefäßes versammelt. Die vorliegende Arbeit erörtert Ansätze für „Zeitmaschinen“ und superluminale Prozesse, die in Einklang mit der modernen Physik stehen. Besprochen werden u. a. die Tachyonen-Hypothese, Tiplers rotierender Zylinder, der Gödel-Kosmos, der Anti-de-Sitter-Kosmos, die sogenannten „Wurmlöcher“ und die Alcubierre-Metrik. Zugleich sollen Ansätze vorgestellt werden (z. B. Eternalismus, Viele-Welten-Modell, Prinzip der konsistenten Geschichte), die Lösungsversuche für die Paradoxien von Vergangenheitsreisen bieten. Um die Reisen in die Vergangenheit und Reisen mit Überlichtgeschwindigkeit scheint es zu stehen wie mit einer Anfrage an Radio Jerewan; die Antwort lautet stets: „Im Prinzip ja, aber …“ Doch die Faszination dieser Idee wird weiterhin Stoff für die „Fiction“ liefern. / Time travel and superluminal travel are two of mankind's dreams. They inspire our imagination and provide material for bizarre stories. A work on the subject of time travel and superluminal travel forces us to re-examine our concept of "time". The complexity and the contradictory nature this subject makes it difficult to be more precise about "time". On its deepest subjective side, time is a means of perception, a biological rhythm, a social phenomenon in terms of our collective understanding of time. But it is also a physical parameter. Einstein's Theory of Relativity revolutionised our idea of space and time by freeing us from the Newtonian concept of absolute space and absolute time. The "problem of time travel", a subject that Wells wrote about just ten years before as mere fiction, was now a discussion worthy of physics. Einstein's Special Theory of Relativity (1905), by predicting the effects of time dilation, allowed for "travels into the future" and Einstein's Theory of Gravity used closed time-like lines for solutions to calculations about time travel (for example, the Gödel Universe and the Anti-de Sitter Universe). However, a trip to a time warp would immediately involve a whole set of paradoxes (for example, the grandfather paradox and the information paradox) and semantic inconsistencies. Surprisingly, the fundamental laws of physics (apart from extremely rare and non-emergent macroscopic quantum mechanical effects) are not violated by the concept of time reversal. Yet, in nature, there still seems to be a fundamental prohibition against time travel to the past. Physicist Dieter Zeh, whose position is more closely presented in the final chapter of this work, supports the view that science fiction literature on the subject of "time travel" is overwhelmingly based on simple conceptual errors. The processes used in this literature, which are based on the General Theory of Relativity, at best, are just as "theoretically possible" as a gas which gathers itself into the corner of a container. This work discusses approaches for "time machines" and superluminal travel which are consistent with modern physics. Some of the discussions that will be presented are the tachyon hypothesis, Tipler's rotating cylinder, the Gödel Universe, the Anti-de Sitter Universe, so-called "wormholes" and the Alcubierre-metric. At the same time, approaches will be presented (for example, Eternalism, the Many-Worlds Interpretation and the Consistent Histories Approach) that will provide attempts to find a solution for paradoxes regarding time travel to the past. Questions about time travel to the past and superluminal travel are like the questions asked on Radio Yerevan. The answer is always, "In principle yes, but…" But the fascination about time travel will continue to provide material for "fiction".