Impossability Theory

Time Travel ◽  
2020 ◽  
pp. 128-144
Author(s):  
Nikk Effingham
Keyword(s):  
Time Travel ◽  
Metaphysical Possibility ◽  
Physical Possibility ◽  
Selection Of

My preferred solution to the Grandfather Paradox is to say that time travellers have the ability to do the metaphysically impossible (and so I can kill my grandfather), even though they never will. This requires physical possibility to outstrip metaphysical possibility. This chapter argues that, given the dialectic one must be in when considering the Grandfather Paradox, it’s reasonable to assume just that. It then argues that, given that assumption, impossability theory follows. The rest of the chapter explains Jack Spencer’s argument for the same conclusion, before discussing how impossability theory can be applied to a selection of paradoxes other than the Grandfather Paradox, and which have nothing to do with time travel.

Changing the Past

Time Travel ◽  
2020 ◽  
pp. 66-90
Author(s):  
Nikk Effingham
Keyword(s):  
Time Travel ◽  
Metaphysical Possibility ◽  
The Past ◽  
The Future ◽  
Temporal Dimensions

Here’s a paradox: time travel is possible; were it possible, you could change the past; it’s impossible to change the past. This chapter argues that we can resolve this paradox in two different ways. One way, the ‘Ludovician’ method, is to accept that changing the past is impossible but deny that time travel requires changing the past (and, as part of the chapter’s discussion, it argues both that Ludovicianism is incompatible with the future being open and that the ‘bilking’ argument isn’t problematic). Another way introduces ‘indexed worlds’—i.e. worlds with extra universes or extra-temporal dimensions—at which the past can be changed. The chapter argues for the metaphysical possibility of both Ludovician and indexed worlds.

scholarly journals The Metaphysical Possibility of Time Travel Fictions

Erkenntnis ◽  
2021 ◽  
Author(s):  
Nikk Effingham
Keyword(s):  
Fixed Points ◽  
Time Travel ◽  
Metaphysical Possibility ◽  
The Past

AbstractIn some stories, time travellers cannot change the past. It is widely accepted that this is metaphysically possible. In some stories, time travellers can change the past. Many philosophers have explained how that, too, is metaphysically possible. This paper considers narratives where sometimes the past can change and sometimes it cannot, arguing that this is also something that is possible. Further, I argue that we can make sense of stories where some events appear to be ‘fixed points in time’.

scholarly journals Time Travel and Time Machines

2011 ◽  
Author(s):  
Chris Smeenk ◽  
Christian Wüthrich
Keyword(s):  
Loop Quantum Gravity ◽  
Recent Literature ◽  
Time Travel ◽  
Quantum Theories ◽  
Physical Possibility ◽  
Quantum Behavior ◽  
Theories Of Gravity ◽  
Time Machines ◽  
Full Quantum ◽  
Rule Out

This chapter examines the logical, metaphysical, and physical possibility of time travel understood in the sense of the existence of closed worldlines that can be traced out by physical objects, arguing that none of the purported paradoxes rule out time travel on the grounds of either logic or metaphysics. More relevantly, modern space–time theories such as general relativity seem to permit models that feature closed worldlines. The chapter discusses what this apparent physical possibility of time travel means, and, furthermore, reviews the recent literature on so-called time machines, of devices that produce closed worldlines where none would have existed otherwise. Finally, it investigates what the implications of the quantum behavior of matter might be for the possibility of time travel, and explicates in what sense time travel might be possible according to leading contenders for full quantum theories of gravity such as string theory and loop quantum gravity.

Interfacing with the past: Archival digitization and the construction of digital depository

2020 ◽  
pp. 135485652097299
Author(s):  
Sharon Ringel
Keyword(s):  
Time Travel ◽  
The Political ◽  
Technical Process ◽  
National Library ◽  
Digital History ◽  
The Past ◽  
Archival Documents ◽  
Digital Collection ◽  
Cultural Tensions ◽  
Selection Of

This article examines the construction of a digital collection. Using a theoretical framework adapted from digital history and historiography, it will investigate the implications of archival digitization. Through an empirical study of the National Library of Israel’s digital depository of ephemera entitled ‘Time Travel’, the article demonstrates how the selection of archival records for digital preservation, the design of the search interface, and the crowdsourcing of metadata collection are all directing archive users toward certain narratives about Israeli history and away from others. Drawing on interviews with professionals, analysis of reports, and investigations of user experience, I will unearth the political, religious, and cultural tensions that lie beneath the surface of ‘Time Travel’. This research demonstrates that digitization of archival documents is not just a technical process but a cultural, social, and political one as well.

Constrict Theories

Time Travel ◽  
2020 ◽  
pp. 103-108
Author(s):  
Nikk Effingham
Keyword(s):  
Thought Experiment ◽  
Laws Of Nature ◽  
Time Travel ◽  
Metaphysical Possibility ◽  
Law Of Nature ◽  
Chronology Protection ◽  
Self Consistency ◽  
Rule Out

‘Constrict theories’ are those theories whereby a law of nature resolves the Grandfather Paradox. This chapter introduces two such positions: the Chronology Protection Conjecture (whereby the laws rule out time travel) and Novikov’s Principle of Self-Consistency (which says that time travel is possible but that the laws of nature will ensure that there are no paradoxes). This chapter argues that because the Grandfather Paradox is a thought experiment, and aims to conclude something about metaphysical possibility, these theories are irrelevant. The chapter ends by discussing whether we should reinterpret the Grandfather Paradox as arguing for time travel’s physical impossibility instead.

scholarly journals Study of a Relationship between the Criteria for Selection of the Transport Technology for the Passengers Carriage using the Dematel Method

2020 ◽  
Vol 22 (4) ◽  
pp. 46-55
Author(s):  
Svetla Stoilova
Keyword(s):  
Decision Making ◽  
Road Transport ◽  
Business Group ◽  
Time Travel ◽  
Operating Costs ◽  
Transport Costs ◽  
Ticket Price ◽  
Criteria For Evaluation ◽  
Criteria For Selection ◽  
Selection Of

This study defines criteria and sub-criteria for evaluation of the transport technology for carriage of passengers by railway and road transport. The main criteria are divided into four groups: business, environmental, social and technological, named BEST analysis. Twenty-four sub-criteria have been examined. The method of multi-criteria analysis Decision Making Trial and Evaluation Laboratory (DEMATEL) has been applied to analyse importance and the relations between the criteria. Results show that e criteria of the great importance are business group (29.47%) and technological group (27.49%). The sub-criteria: transport costs for fuel (7.83%); ticket price (8.29%); time travel (6.99%); directness (6.47%) and direct operating costs (6.30%) are the most important. The defined criteria and subcriteria can be applied for evaluation, comparison and selection the transportation variant.

Cognitive gadgets and cognitive priors

2019 ◽  
Vol 42 ◽  
Author(s):  
Gian Domenico Iannetti ◽  
Giorgio Vallortigara
Keyword(s):  
Cognitive Neuroscience ◽  
Selection Of

Abstract Some of the foundations of Heyes’ radical reasoning seem to be based on a fractional selection of available evidence. Using an ethological perspective, we argue against Heyes’ rapid dismissal of innate cognitive instincts. Heyes’ use of fMRI studies of literacy to claim that culture assembles pieces of mental technology seems an example of incorrect reverse inferences and overlap theories pervasive in cognitive neuroscience.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

Measurements of the Cape Astrometric Survey of the Southern Hemisphere

1978 ◽  
Vol 48 ◽  
pp. 515-521
Author(s):  
W. Nicholson
Keyword(s):  
Southern Hemisphere ◽  
Automatic Measuring ◽  
Measuring Machine ◽  
Final Selection ◽  
Selection Of

SummaryA routine has been developed for the processing of the 5820 plates of the survey. The plates are measured on the automatic measuring machine, GALAXY, and the measures are subsequently processed by computer, to edit and then refer them to the SAO catalogue. A start has been made on measuring the plates, but the final selection of stars to be made is still a matter for discussion.

Application of Improved Voltage Compensation in the SEM to Imaging of Organic Materials

1973 ◽  
Vol 31 ◽  
pp. 444-445
Author(s):  
P.J. Killingworth ◽  
M. Warren
Keyword(s):  
Electron Beam ◽  
Organic Materials ◽  
Operating Parameters ◽  
Low Density ◽  
Beam Diameter ◽  
Incident Electron Beam ◽  
Specimen Material ◽  
Voltage Compensation ◽  
Selection Of ◽  
Scanning Electron

Ultimate resolution in the scanning electron microscope is determined not only by the diameter of the incident electron beam, but by interaction of that beam with the specimen material. Generally, while minimum beam diameter diminishes with increasing voltage, due to the reduced effect of aberration component and magnetic interference, the excited volume within the sample increases with electron energy. Thus, for any given material and imaging signal, there is an optimum volt age to achieve best resolution.In the case of organic materials, which are in general of low density and electric ally non-conducting; and may in addition be susceptible to radiation and heat damage, the selection of correct operating parameters is extremely critical and is achiev ed by interative adjustment.

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