38,756 research outputs found
Probability in the Everett World: Comments on Wallace and Greaves
It is often objected that the Everett interpretation of QM cannot make sense
of quantum probabilities, in one or both of two ways: either it can't make
sense of probability at all, or it can't explain why probability should be
governed by the Born rule. David Deutsch has attempted to meet these
objections. He argues not only that rational decision under uncertainty makes
sense in the Everett interpretation, but also that under reasonable
assumptions, the credences of a rational agent in an Everett world should be
constrained by the Born rule. David Wallace has developed and defended
Deutsch's proposal, and greatly clarified its conceptual basis. In particular,
he has stressed its reliance on the distinguishing symmetry of the Everett
view, viz., that all possible outcomes of a quantum measurement are treated as
equally real. The argument thus tries to make a virtue of what has usually been
seen as the main obstacle to making sense of probability in the Everett world.
In this note I outline some objections to the Deutsch-Wallace argument, and to
related proposals by Hilary Greaves about the epistemology of Everettian QM.
(In the latter case, my arguments include an appeal to an Everettian analogue
of the Sleeping Beauty problem.) The common thread to these objections is that
the symmetry in question remains a very significant obstacle to making sense of
probability in the Everett interpretation.Comment: 17 pages; no figures; LaTe
Playing popular science
Popular science is a critical form of science communication and dissemination. While scientific journals and detailed textbooks are well suited to dissemination of detailed theories and findings within academic communities, there is a definitive need to inform the general public of key scientific concepts and challenges. Indeed, this is increasingly seen as a central part of any research project or funding bid: in the United Kingdom, the Research Councils stipulate a need to consider public engagement and outreach in research proposals For scientists, the popular science book has long been a medium of choice, primarily because they already have a great deal of experience in writing. But in recent years scientific researchers have been increasingly engaged with other forms of popular science communication, including radio and television broadcasting. Early careers researchers are now provided with training in these areas, including guidance on how to develop programme proposals and how to write, present, direct, and edit materials for print, the airwaves, and screen. In effect, today’s scientists are expected to engage directly with popular science journalism not merely as scientific advisors, but as the writers, directors, and broadcasters.This event involved an exhibition and discussion of four popular science games, co-designed by scientific experts and designed and developed by students at Abertay University. The four games were: (1) Namaka by Crowbar Games Co-designed by Ecotoxicologist Dr Brian Quinn (2) Tides: A Shark Tale by Benthos Games Co-designed by Immunologist and sharks expert Dr Helen Dooley (3) Orbs by Quantessential Games Co-designed by Quantum Physicist Dr Erik Gauger (4) Cell Cycle by Type 3 Games Co-designed by Cell Biologist and cancer researcher Dr Adrian Sauri
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The Language of the cybersouls
Debates about technology are mostly staged in a grand setting: presented as the sinister toolkit of authoritarian organisations, or as the progressive fabric of the future. Yet everyone is involved in technology as part of every microscopic action in every humdrum life. How do theories about technology cope with this political spectrum? One option is to treat technology as we treat language and specifically use Wittgenstein’s language games as an analogy. So that technology, like language, becomes inseparable from us and an intimate part of us, and this merging of technology and the human transforms us all into cyborgs
Are There Quantum Effects Coming from Outside Space-time? Nonlocality, free will and "no many-worlds"
Observing the violation of Bell's inequality tells us something about all
possible future theories: they must all predict nonlocal correlations. Hence
Nature is nonlocal. After an elementary introduction to nonlocality and a brief
review of some recent experiments, I argue that Nature's nonlocality together
with the existence of free will is incompatible with the many-worlds view of
quantum physics.Comment: Talk presented at the meeting "Is Science Compatible with Our Desire
for Freedom?" organised by the Social Trends Institute at the IESE Business
School in Barcelona, Octobre 201
Cheat Sensitive Quantum Bit Commitment
We define cheat sensitive cryptographic protocols between mistrustful parties
as protocols which guarantee that, if either cheats, the other has some nonzero
probability of detecting the cheating. We give an example of an unconditionally
secure cheat sensitive non-relativistic bit commitment protocol which uses
quantum information to implement a task which is classically impossible; we
also describe a simple relativistic protocol.Comment: Final version: a slightly shortened version of this will appear in
PRL. Minor corrections from last versio
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