Oliver Heaviside: an accidental time traveller

Author(s):  
Paul J. Nahin

A little discussed aspect of Heaviside's work in electromagnetics concerned faster-than-light (FTL) charged particles, precursors to the hypothetical tachyon and his discovery that such motion should produce a characteristic radiation signature (now called Cherenkov radiation ). When Heaviside wrote, the time travel implications of FTL were not known (Einstein was still a teenager), and in this paper some speculations are offered on what Heaviside would have thought of FTL time travel, and of the associated (now classic) time travel paradoxes, including the possibility (or not) of sending information into the past. This article is part of the theme issue ‘Celebrating 125 years of Oliver Heaviside's ‘Electromagnetic Theory’’.

2014 ◽  
Vol 7 (2) ◽  
pp. 136-151 ◽  
Author(s):  
Sung-Ae Lee

To displace a character in time is to depict a character who becomes acutely conscious of his or her status as other, as she or he strives to comprehend and interact with a culture whose mentality is both familiar and different in obvious and subtle ways. Two main types of time travel pose a philosophical distinction between visiting the past with knowledge of the future and trying to inhabit the future with past cultural knowledge, but in either case the unpredictable impact a time traveller may have on another society is always a prominent theme. At the core of Japanese time travel narratives is a contrast between self-interested and eudaimonic life styles as these are reflected by the time traveller's activities. Eudaimonia is a ‘flourishing life’, a life focused on what is valuable for human beings and the grounding of that value in altruistic concern for others. In a study of multimodal narratives belonging to two sets – adaptations of Tsutsui Yasutaka's young adult novella The Girl Who Leapt Through Time and Yamazaki Mari's manga series Thermae Romae – this article examines how time travel narratives in anime and live action film affirm that eudaimonic living is always a core value to be nurtured.


2020 ◽  
Author(s):  
Donna Rose Addis

Mental time travel (MTT) is defined as projecting the self into the past and the future. Despite growing evidence of the similarities of remembering past and imagining future events, dominant theories conceive of these as distinct capacities. I propose that memory and imagination are fundamentally the same process – constructive episodic simulation – and demonstrate that the ‘simulation system’ meets the three criteria of a neurocognitive system. Irrespective of whether one is remembering or imagining, the simulation system: (1) acts on the same information, drawing on elements of experience ranging from fine-grained perceptual details to coarser-grained conceptual information and schemas about the world; (2) is governed by the same rules of operation, including associative processes that facilitate construction of a schematic scaffold, the event representation itself, and the dynamic interplay between the two (cf. predictive coding); and (3) is subserved by the same brain system. I also propose that by forming associations between schemas, the simulation system constructs multi-dimensional cognitive spaces, within which any given simulation is mapped by the hippocampus. Finally, I suggest that simulation is a general capacity that underpins other domains of cognition, such as the perception of ongoing experience. This proposal has some important implications for the construct of ‘MTT’, suggesting that ‘time’ and ‘travel’ may not be defining, or even essential, features. Rather, it is the ‘mental’ rendering of experience that is the most fundamental function of this simulation system, enabling humans to re-experience the past, pre-experience the future, and also comprehend the complexities of the present.


Author(s):  
Donald C. Williams

This chapter is about the arrow or direction of time against the backdrop of the pure manifold theory. It is accepted that the fact that time has a direction ought to be explained. It is proposed that the arrow of time is grounded in deeper facts about the four-dimensional nature of each object in the manifold and in facts about the overall four-dimensional shape of the universe. Towards the end of the chapter the possibility of time travel is discussed. It is argued that time travel is metaphysically possible and that there is a reasonable and intelligible sense in which a time traveler can and cannot change the past, according to the pure manifold theory.


2021 ◽  
Vol 11 (8) ◽  
pp. 3711
Author(s):  
Selma Rizvić ◽  
Dušanka Bošković ◽  
Vensada Okanović ◽  
Ivona Ivković Kihić ◽  
Irfan Prazina ◽  
...  

Bosnia and Herzegovina (BH) has a very picturesque past. Founded in 11th century, it has always been a crossroads of faiths and civilizations. Extended Reality (XR) technologies can finally take us to time travel into this history, enable us to experience past events and meet historical characters. In this paper, we overview the latest applications we developed that use Virtual Reality (VR) video, Virtual and Augmented Reality (AR) for interactive digital storytelling about BH history. “Nine dissidents” is the first BH VR documentary, tackling a still tricky subject of dissidents in the Socialist Yugoslavia, artists and writers falsely accused, persecuted and still forbidden. “Virtual Museum of Old Crafts” aims to present and preserve crafts intangible heritage through Virtual Reality. “Battle on Neretva VR” is recreating a famous WWII battle offering the users to experience it and meet comrade Tito, the commander of the Yugoslav Liberation Army. “Sarajevo 5D” shows the cultural monuments from Sarajevo that do not exist anymore in physical form using Augmented Reality. Through user experience studies, we measure the user immersion and edutainment of these applications and show the potential of XR for the presentation and preservation of cultural heritage.


2021 ◽  
Vol 11 (3) ◽  
pp. 43-49
Author(s):  
Hamdoon A. Khan ◽  

With the consideration of the light which carries the photon particles, the Lorentz transformation was constructed with an impressive mathematical approach. But the generalization of that equation for all the velocities of the universe is direct enforcement on other things not to travel faster than light. It has created serious issues in every scientific research that was done in the last century based on the special theory of relativity. This paper replaces the velocity of light with some other velocities and shows us the possible consequences and highlights the issues of special relativity. If I travel through my past or future and was able to see another me there, who would be the real Hamdoon I or the one I see there in the past or future! If the real one is only me, the one I saw, is not me, so, I could not travel through my or someone else's past or future. Therefore, no one can travel through time. If both of us are the same, can the key of personal identity be duplicated or be separated into two or more parts? These are some of the fundamental philosophical arguments that annihilate the concept of time travel which is one of the sequels of special relativity.


2018 ◽  
Vol 374 (1763) ◽  
pp. 20170405 ◽  
Author(s):  
Heather M. Kharouba ◽  
Jayme M. M. Lewthwaite ◽  
Rob Guralnick ◽  
Jeremy T. Kerr ◽  
Mark Vellend

Over the past two decades, natural history collections (NHCs) have played an increasingly prominent role in global change research, but they have still greater potential, especially for the most diverse group of animals on Earth: insects. Here, we review the role of NHCs in advancing our understanding of the ecological and evolutionary responses of insects to recent global changes. Insect NHCs have helped document changes in insects' geographical distributions, phenology, phenotypic and genotypic traits over time periods up to a century. Recent work demonstrates the enormous potential of NHCs data for examining insect responses at multiple temporal, spatial and phylogenetic scales. Moving forward, insect NHCs offer unique opportunities to examine the morphological, chemical and genomic information in each specimen, thus advancing our understanding of the processes underlying species’ ecological and evolutionary responses to rapid, widespread global changes. This article is part of the theme issue ‘Biological collections for understanding biodiversity in the anthropocene’.


Author(s):  
Steven Moran ◽  
Nicholas A. Lester ◽  
Eitan Grossman

In this paper, we investigate evolutionarily recent changes in the distributions of speech sounds in the world's languages. In particular, we explore the impact of language contact in the past two millennia on today's distributions. Based on three extensive databases of phonological inventories, we analyse the discrepancies between the distribution of speech sounds of ancient and reconstructed languages, on the one hand, and those in present-day languages, on the other. Furthermore, we analyse the degree to which the diffusion of speech sounds via language contact played a role in these discrepancies. We find evidence for substantive differences between ancient and present-day distributions, as well as for the important role of language contact in shaping these distributions over time. Moreover, our findings suggest that the distributions of speech sounds across geographic macro-areas were homogenized to an observable extent in recent millennia. Our findings suggest that what we call the Implicit Uniformitarian Hypothesis, at least with respect to the composition of phonological inventories, cannot be held uncritically. Linguists who would like to draw inferences about human language based on present-day cross-linguistic distributions must consider their theories in light of even short-term language evolution. This article is part of the theme issue ‘Reconstructing prehistoric languages’.


Disputatio ◽  
2020 ◽  
Vol 12 (57) ◽  
pp. 137-165
Author(s):  
Ned Markosian

AbstractI argue that time travel to the past is impossible, given a certain metaphysical theory, namely, The Dynamic Theory of Time. I first spell out my particular way of capturing the difference between The Dynamic Theory of Time and its rival, The Static Theory of Time. Next I offer four different arguments for the conclusion that The Dynamic Theory is inconsistent with the possibility of time travel to the past. Then I argue that, even if I am wrong about this, it will still be true that The Dynamic Theory entails that you should not want to travel back to the past. Finally, I conclude by considering a puzzle that arises for those who believe that time travel to the past is metaphysically impossible: What exactly are we thinking about when we seem to be thinking about traveling back in time? For it certainly does not feel like we are thinking about something that is metaphysically impossible.


2005 ◽  
Vol 20 (29) ◽  
pp. 6897-6899 ◽  
Author(s):  
S. P. KNURENKO ◽  
A. A. IVANOV ◽  
V. A. KOLOSOV ◽  
Z. E. PETROV ◽  
I. YE. SLEPTSOV ◽  
...  

Fraction of energy, E em /E0, transferred to the electron-photon component of EAS at E0 = 1015 ± 1019 eV was estimated by using the Cherenkov radiation data and the data on charged particles obtained at the Yakutsk EAS array. The results are compared with predictions of different models for energy dissipation into the EAS electron-photon component and with calculations performed with different primary nuclei content. In the energy ranges 1015 ± 1016 eV and 1018 ± 1019 eV , the ratio E em /E0 is equal to (77 ± 2)% and (88 ± 2)%, respectively, that does not contradict to a mixed composition of primary particles in the first energy interval and purely proton composition in the second one.


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