Time Travel and Time Machines
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|||GET||| a Book That Was Lost Thirty-Five Stories 1St Edition
A BOOK THAT WAS LOST THIRTY-FIVE STORIES 1ST EDITION DOWNLOAD FREE Alan Mintz | 9781592642540 | | | | | The First Forty Nine Stories Hemingway Ernest 9780353247529 Adler Transcript of the original source. Nevertheless, the editors steadfastly maintain that average readers are capable of understanding far more than the critics deem possible. See also: Outline of science fiction. Wright, who drove a cab. Retrieved 27 February There was also a tanning bed used in an episode, a product that wasn't introduced to North America until Hollywood, here I come! Understanding Kurt Vonnegut. Conventions in fandom, often shortened as "cons," such as " comic-con " are held in cities around the worldcatering to a local, regional, national, or international membership. Neo-Fan's Guidebook. They also tend to support the space program and the idea of contacting extraterrestrial civilizations. Chicago Sun-Times. Retrieved 10 April Further information: Skiffy. Mary Shelley wrote a number of science fiction novels including Frankenstein; or, The Modern Prometheusand is considered a major writer of the Romantic Age. Science fiction at Wikipedia's sister projects. Escapist Magazine. I feel that with being a parent. Atlas Obscura. You want to see some jazz? The character, a peripheral one at first, became central. Views Read Edit View history. Feldman urged him to stay. Joining the Marines gave Driver a sense A Book That Was Lost Thirty-Five Stories 1st edition purpose and some distance from his conservative religious upbringing. Faster-than-light communication Wormholes. Respected authors of mainstream literature have written science fiction. Retrieved 4 March Wolfe, Gary K. Science fiction portal. This was almost certainly a cost-saving measure. -
GURPS4E Ultra-Tech.Qxp
Written by DAVID PULVER, with KENNETH PETERS Additional Material by WILLIAM BARTON, LOYD BLANKENSHIP, and STEVE JACKSON Edited by CHRISTOPHER AYLOTT, STEVE JACKSON, SEAN PUNCH, WIL UPCHURCH, and NIKOLA VRTIS Cover Art by SIMON LISSAMAN, DREW MORROW, BOB STEVLIC, and JOHN ZELEZNIK Illustrated by JESSE DEGRAFF, IGOR FIORENTINI, SIMON LISSAMAN, DREW MORROW, E. JON NETHERLAND, AARON PANAGOS, CHRISTOPHER SHY, BOB STEVLIC, and JOHN ZELEZNIK Stock # 31-0104 Version 1.0 – May 22, 2007 STEVE JACKSON GAMES CONTENTS INTRODUCTION . 4 Adjusting for SM . 16 PERSONAL GEAR AND About the Authors . 4 EQUIPMENT STATISTICS . 16 CONSUMER GOODS . 38 About GURPS . 4 Personal Items . 38 2. CORE TECHNOLOGIES . 18 Clothing . 38 1. ULTRA-TECHNOLOGY . 5 POWER . 18 Entertainment . 40 AGES OF TECHNOLOGY . 6 Power Cells. 18 Recreation and TL9 – The Microtech Age . 6 Generators . 20 Personal Robots. 41 TL10 – The Robotic Age . 6 Energy Collection . 20 TL11 – The Age of Beamed and 3. COMMUNICATIONS, SENSORS, Exotic Matter . 7 Broadcast Power . 21 AND MEDIA . 42 TL12 – The Age of Miracles . 7 Civilization and Power . 21 COMMUNICATION AND INTERFACE . 42 Even Higher TLs. 7 COMPUTERS . 21 Communicators. 43 TECH LEVEL . 8 Hardware . 21 Encryption . 46 Technological Progression . 8 AI: Hardware or Software? . 23 Receive-Only or TECHNOLOGY PATHS . 8 Software . 24 Transmit-Only Comms. 46 Conservative Hard SF. 9 Using a HUD . 24 Translators . 47 Radical Hard SF . 9 Ubiquitous Computing . 25 Neural Interfaces. 48 CyberPunk . 9 ROBOTS AND TOTAL CYBORGS . 26 Networks . 49 Nanotech Revolution . 9 Digital Intelligences. 26 Mail and Freight . 50 Unlimited Technology. 9 Drones . 26 MEDIA AND EDUCATION . 51 Emergent Superscience . -
The Wormhole Hazard
The wormhole hazard S. Krasnikov∗ October 24, 2018 Abstract To predict the outcome of (almost) any experiment we have to assume that our spacetime is globally hyperbolic. The wormholes, if they exist, cast doubt on the validity of this assumption. At the same time, no evidence has been found so far (either observational, or theoretical) that the possibility of their existence can be safely neglected. 1 Introduction According to a widespread belief general relativity is the science of gravita- tional force. Which means, in fact, that it is important only in cosmology, or in extremely subtle effects involving tiny post-Newtonian corrections. However, this point of view is, perhaps, somewhat simplistic. Being con- arXiv:gr-qc/0302107v1 26 Feb 2003 cerned with the structure of spacetime itself, relativity sometimes poses prob- lems vital to whole physics. Two best known examples are singularities and time machines. In this talk I discuss another, a little less known, but, in my belief, equally important problem (closely related to the preceding two). In a nutshell it can be formulated in the form of two question: What princi- ple must be added to general relativity to provide it (and all other physics along with it) by predictive power? Does not the (hypothetical) existence of wormholes endanger that (hypothetical) principle? ∗Email: [email protected] 1 2 Global hyperbolicity and predictive power 2.1 Globally hyperbolic spacetimes The globally hyperbolic spacetimes are the spacetimes with especially sim- ple and benign causal structure, the spacetimes where we can use physical theories in the same manner as is customary in the Minkowski space. -
Summer 2017 Astron 9 Week 5 Final Version
RELATIVITY OF SPACE AND TIME IN POPULAR SCIENCE RICHARD ANANTUA PREDESTINATION (MON JUL 31) REVIEW OF JUL 24, 26 & 28 • Flying atomic clocks, muon decay, light bending around stars and gravitational waves provide experimental confirmation of relativity • In 1919, Einstein’s prediction for the deflection of starlight was confirmed by • The 1971 Hafele-Keating experiment confirmed • The 1977 CERN muon experiment confirmed • In 2016 LIGO confirmed the existence of REVIEW OF JUL 24, 26 & 28 • Flying atomic clocks, muon decay, light bending around stars and gravitational waves provide experimental confirmation of relativity • In 1919, Einstein’s prediction for the deflection of starlight was confirmed by Sir Arthur Eddington • The 1971 Hafele-Keating experiment confirmed motional and gravitational time dilation • The 1977 CERN muon experiment confirmed motional time dilation • In 2016 LIGO confirmed the existence of gravitational waves TIME TRAVEL IN RELATIVITY • Methods of time travel theoretically possible in relativity are • (Apparently) faster than light travel – window into the past? • Closed timelike curved • (Apparent) paradoxes with time travel • Kill your grandfather – past time travel may alter seemingly necessary conditions for the future time traveler to have started the journey • Predestination - apparent cause of past event is in the future SPECIAL RELATIVISTIC VELOCITY ADDITION • In special relativity, no object or information can travel faster than light, a fact reflected in the relativistic law of composition of velocities v &v vAB v = $% %' A !" v$%v%' (& * ) vBC B C • vAB is the (1D) velocity of A with respect to B • vBC is the (1D) velocity of B with respect to C POP QUIZ - FASTER THAN LIGHT TRAVEL • A spaceship traveling at v>c is returning from a moving planet (L0 away right before the journey). -
Engineering the Quantum Foam
Engineering the Quantum Foam Reginald T. Cahill School of Chemistry, Physics and Earth Sciences, Flinders University, GPO Box 2100, Adelaide 5001, Australia [email protected] _____________________________________________________ ABSTRACT In 1990 Alcubierre, within the General Relativity model for space-time, proposed a scenario for ‘warp drive’ faster than light travel, in which objects would achieve such speeds by actually being stationary within a bubble of space which itself was moving through space, the idea being that the speed of the bubble was not itself limited by the speed of light. However that scenario required exotic matter to stabilise the boundary of the bubble. Here that proposal is re-examined within the context of the new modelling of space in which space is a quantum system, viz a quantum foam, with on-going classicalisation. This model has lead to the resolution of a number of longstanding problems, including a dynamical explanation for the so-called `dark matter’ effect. It has also given the first evidence of quantum gravity effects, as experimental data has shown that a new dimensionless constant characterising the self-interaction of space is the fine structure constant. The studies here begin the task of examining to what extent the new spatial self-interaction dynamics can play a role in stabilising the boundary without exotic matter, and whether the boundary stabilisation dynamics can be engineered; this would amount to quantum gravity engineering. 1 Introduction The modelling of space within physics has been an enormously challenging task dating back in the modern era to Galileo, mainly because it has proven very difficult, both conceptually and experimentally, to get a ‘handle’ on the phenomenon of space. -
You Zombies, Click and a Novel, 1632, Both of Which Are Available Online from Links in the Handout
Instructor's notes to F402 Time Travel in Science Fiction Session 1 – Introduction Welcome to F402, Time Travel in Science Fiction. The objective of this course is to help you to read, understand and enjoy stories in the genre. The course is in two parts; the first is Today's lecture and discussion on the genre while the second is class discussions of two stories of opposite types. click The reading assignment consists of a short story, All You Zombies, click and a novel, 1632, both of which are available online from links in the handout. click For the convenience of those who prefer dead trees, I have listed a number of anthologies1 containing All You Zombies. Reading Assignment for Sessions 2-3 click All You Zombies is one of two tour de force stories by Robert A. Heinlein that left their mark on the genre for decades. Please read All You Zombies prior to the next session click and 1632 click click Part One, chapters 1-14 prior to the third session. Esc Session 1 Keep in mind that science fiction is a branch of literature, so the normal criteria of, e.g., characterization, consistency, continuity, plot structure, style, apply; I welcome comments, especially from those who have expertise in those areas. In addition, while a science fiction author must rely on the willing suspension of disbelief, he should do so sparingly. There is a lapse of continuity in 1632 between chapters 8 and 9; see whether you can spot it. I will suggest specific discussion points to start each discussion, but please bring up any other issues that you believe to be important or interesting. -
Thermodynamics of Exotic Matter with Constant W = P/E Arxiv:1108.0824
Thermodynamics of exotic matter with constant w = P=E Ernst Trojan and George V. Vlasov Moscow Institute of Physics and Technology PO Box 3, Moscow, 125080, Russia October 25, 2018 Abstract We consider a substance with equation of state P = wE at con- stant w and find that it is an ideal gas of quasi-particles with the wq energy spectrum "p ∼ p that can constitute either regular matter (when w > 0) or exotic matter (when w < 0) in a q-dimensional space. Particularly, an ideal gas of fermions or bosons with the en- 4 3 ergy spectrum "p = m =p in 3-dimensional space will have the pres- sure P = −E. Exotic material, associated with the dark energy at E + P < 0, is also included in analysis. We determine the properties of regular and exotic ideal Fermi gas at zero temperature and derive a low-temperature expansion of its thermodynamical functions at fi- nite temperature. The Fermi level of exotic matter is shifted below the Fermi energy at zero temperature, while the Fermi level of regular matter is always above it. The heat capacity of any fermionic sub- stance is always linear dependent on temperature, but exotic matter has negative entropy and negative heat capacity. 1 Introduction arXiv:1108.0824v2 [cond-mat.stat-mech] 4 Aug 2011 The equation of state (EOS) is a fundamental characteristic of matter. It is a functional link P (E) between the pressure P and the energy density E. Its knowledge allows to predict the behavior of substance which appears in 1 various problems in astrophysics, including cosmology and physics of neutron stars. -
Closed Timelike Curves Make Quantum and Classical Computing Equivalent
Closed Timelike Curves Make Quantum and Classical Computing Equivalent Scott Aaronson∗ John Watrous† MIT University of Waterloo Abstract While closed timelike curves (CTCs) are not known to exist, studying their consequences has led to nontrivial insights in general relativity, quantum information, and other areas. In this paper we show that if CTCs existed, then quantum computers would be no more powerful than classical computers: both would have the (extremely large) power of the complexity class PSPACE, consisting of all problems solvable by a conventional computer using a polynomial amount of memory. This solves an open problem proposed by one of us in 2005, and gives an essentially complete understanding of computational complexity in the presence of CTCs. Following the work of Deutsch, we treat a CTC as simply a region of spacetime where a “causal consistency” condition is imposed, meaning that Nature has to produce a (probabilistic or quantum) fixed-point of some evolution operator. Our conclusion is then a consequence of the following theorem: given any quantum circuit (not necessarily unitary), a fixed-point of the circuit can be (implicitly) computed in polynomial space. This theorem might have independent applications in quantum information. 1 Introduction The possibility of closed timelike curves (CTCs) within general relativity and quantum gravity theories has been studied for almost a century [11, 15, 13]. A different line of research has sought to understand the implications of CTCs, supposing they existed, for quantum mechanics, computation, and information [9, 8, 5]. In this paper we contribute to the latter topic, by giving the first complete characterization of the computational power of CTCs. -
The Philosophy and Physics of Time Travel: the Possibility of Time Travel
University of Minnesota Morris Digital Well University of Minnesota Morris Digital Well Honors Capstone Projects Student Scholarship 2017 The Philosophy and Physics of Time Travel: The Possibility of Time Travel Ramitha Rupasinghe University of Minnesota, Morris, [email protected] Follow this and additional works at: https://digitalcommons.morris.umn.edu/honors Part of the Philosophy Commons, and the Physics Commons Recommended Citation Rupasinghe, Ramitha, "The Philosophy and Physics of Time Travel: The Possibility of Time Travel" (2017). Honors Capstone Projects. 1. https://digitalcommons.morris.umn.edu/honors/1 This Paper is brought to you for free and open access by the Student Scholarship at University of Minnesota Morris Digital Well. It has been accepted for inclusion in Honors Capstone Projects by an authorized administrator of University of Minnesota Morris Digital Well. For more information, please contact [email protected]. The Philosophy and Physics of Time Travel: The possibility of time travel Ramitha Rupasinghe IS 4994H - Honors Capstone Project Defense Panel – Pieranna Garavaso, Michael Korth, James Togeas University of Minnesota, Morris Spring 2017 1. Introduction Time is mysterious. Philosophers and scientists have pondered the question of what time might be for centuries and yet till this day, we don’t know what it is. Everyone talks about time, in fact, it’s the most common noun per the Oxford Dictionary. It’s in everything from history to music to culture. Despite time’s mysterious nature there are a lot of things that we can discuss in a logical manner. Time travel on the other hand is even more mysterious. -
Light Rays, Singularities, and All That
Light Rays, Singularities, and All That Edward Witten School of Natural Sciences, Institute for Advanced Study Einstein Drive, Princeton, NJ 08540 USA Abstract This article is an introduction to causal properties of General Relativity. Topics include the Raychaudhuri equation, singularity theorems of Penrose and Hawking, the black hole area theorem, topological censorship, and the Gao-Wald theorem. The article is based on lectures at the 2018 summer program Prospects in Theoretical Physics at the Institute for Advanced Study, and also at the 2020 New Zealand Mathematical Research Institute summer school in Nelson, New Zealand. Contents 1 Introduction 3 2 Causal Paths 4 3 Globally Hyperbolic Spacetimes 11 3.1 Definition . 11 3.2 Some Properties of Globally Hyperbolic Spacetimes . 15 3.3 More On Compactness . 18 3.4 Cauchy Horizons . 21 3.5 Causality Conditions . 23 3.6 Maximal Extensions . 24 4 Geodesics and Focal Points 25 4.1 The Riemannian Case . 25 4.2 Lorentz Signature Analog . 28 4.3 Raychaudhuri’s Equation . 31 4.4 Hawking’s Big Bang Singularity Theorem . 35 5 Null Geodesics and Penrose’s Theorem 37 5.1 Promptness . 37 5.2 Promptness And Focal Points . 40 5.3 More On The Boundary Of The Future . 46 1 5.4 The Null Raychaudhuri Equation . 47 5.5 Trapped Surfaces . 52 5.6 Penrose’s Theorem . 54 6 Black Holes 58 6.1 Cosmic Censorship . 58 6.2 The Black Hole Region . 60 6.3 The Horizon And Its Generators . 63 7 Some Additional Topics 66 7.1 Topological Censorship . 67 7.2 The Averaged Null Energy Condition . -
Lecture 40: Science Fact Or Science Fiction? Time Travel
Lecture 40: Science Fact or Science Fiction? Time Travel Key Ideas Travel into the future: Permitted by General Relativity Relativistic starships or strong gravitation Travel back to the past Might be possible with stable wormholes The Grandfather Paradox Hawking’s Chronology Protection Conjecture Into the future…. We are traveling into the future right now without trying very hard. Can we get there faster? What if you want to celebrate New Years in 3000? Simple: slow your clock down relative to the clocks around you. This is permitted by Special and General Relativity Accelerated Clocks According to General Relativity Accelerated clocks run at a slower rate than a clock moving with uniform velocity Choice of accelerated reference frames: Starship accelerated to relativistic (near-light) speeds Close proximity to a very strongly gravitating body (e.g. black holes) A Journey to the Galactic Center Jane is 20, Dick is 22. Jane is in charge of Mission Control. Dick flies to the Galactic Center, 8 kpc away: Accelerates at 1g half-way then Decelerates at 1g rest of the way Studies the Galactic Center for 1 year, then Returns to Earth by the same route Planet of the Warthogs As measured by Dick’s accelerated clock: Round trip (including 1 year of study) takes ~42 years He return at age 22+42=64 years old Meanwhile back on Earth: Dick’s trip takes ~52,000 yrs Jane died long, long ago After a nuclear war, humans have been replaced by sentient warthogs as the dominant species Advantages to taking Astro 162 Dick was smart and took Astro 162 Dick knew about accelerating clocks running slow, and so he could conclude “Ah, there’s been a nuclear war and humans have been replaced by warthogs”. -
The Causal Hierarchy of Spacetimes 3
The causal hierarchy of spacetimes∗ E. Minguzzi and M. S´anchez Abstract. The full causal ladder of spacetimes is constructed, and their updated main properties are developed. Old concepts and alternative definitions of each level of the ladder are revisited, with emphasis in minimum hypotheses. The implications of the recently solved “folk questions on smoothability”, and alternative proposals (as recent isocausality), are also summarized. Contents 1 Introduction 2 2 Elements of causality theory 3 2.1 First definitions and conventions . ......... 3 2.2 Conformal/classical causal structure . ............ 6 2.3 Causal relations. Local properties . ........... 7 2.4 Further properties of causal relations . ............ 10 2.5 Time-separation and maximizing geodesics . ............ 12 2.6 Lightlike geodesics and conjugate events . ............ 14 3 The causal hierarchy 18 3.1 Non-totally vicious spacetimes . ......... 18 3.2 Chronologicalspacetimes . ....... 21 3.3 Causalspacetimes ................................ 21 3.4 Distinguishingspacetimes . ........ 22 3.5 Continuouscausalcurves . ...... 24 3.6 Stronglycausalspacetimes. ........ 26 ± arXiv:gr-qc/0609119v3 24 Apr 2008 3.7 A break: volume functions, continuous I ,reflectivity . 30 3.8 Stablycausalspacetimes. ....... 35 3.9 Causally continuous spacetimes . ......... 39 3.10 Causallysimplespacetimes . ........ 40 3.11 Globallyhyperbolicspacetimes . .......... 42 4 The “isocausal” ladder 53 4.1 Overview ........................................ 53 4.2 Theladderofisocausality . ....... 53 4.3 Someexamples.................................... 55 References 57 ∗Contribution to the Proceedings of the ESI semester “Geometry of Pseudo-Riemannian Man- ifolds with Applications in Physics” (Vienna, 2006) organized by D. Alekseevsky, H. Baum and J. Konderak. To appear in the volume ‘Recent developments in pseudo-Riemannian geometry’ to be published as ESI Lect. Math. Phys., Eur. Math. Soc. Publ. House, Z¨urich, 2008.