scholarly journals The next generation of analogue gravity experiments

2020 ◽  
Vol 378 (2177) ◽  
pp. 20190239 ◽  
Author(s):  
M. J. Jacquet ◽  
S. Weinfurtner ◽  
F. König
Keyword(s):  
Next Generation ◽  
Analogue Gravity

scholarly journals On the limits of experimental knowledge

2020 ◽  
Vol 378 (2177) ◽  
pp. 20190235 ◽  
Author(s):  
P. W. Evans ◽  
K. P. Y. Thébault
Keyword(s):  
Scientific Practice ◽  
Inductive Reasoning ◽  
Reasonable Doubt ◽  
Next Generation ◽  
Experimental Knowledge ◽  
Analogue Gravity ◽  
Analogue Experiments ◽  
Genuine Knowledge

To demarcate the limits of experimental knowledge, we probe the limits of what might be called an experiment. By appeal to examples of scientific practice from astrophysics and analogue gravity, we demonstrate that the reliability of knowledge regarding certain phenomena gained from an experiment is not circumscribed by the manipulability or accessibility of the target phenomena. Rather, the limits of experimental knowledge are set by the extent to which strategies for what we call ‘inductive triangulation’ are available: that is, the validation of the mode of inductive reasoning involved in the source-target inference via appeal to one or more distinct and independent modes of inductive reasoning. When such strategies are able to partially mitigate reasonable doubt, we can take a theory regarding the phenomena to be well supported by experiment. When such strategies are able to fully mitigate reasonable doubt, we can take a theory regarding the phenomena to be established by experiment. There are good reasons to expect the next generation of analogue experiments to provide genuine knowledge of unmanipulable and inaccessible phenomena such that the relevant theories can be understood as well supported. This article is part of a discussion meeting issue ‘The next generation of analogue gravity experiments’.

scholarly journals Classical hydrodynamics for analogue space–times: open channel flows and thin films

2020 ◽  
Vol 378 (2177) ◽  
pp. 20190233 ◽  
Author(s):  
Germain Rousseaux ◽  
Hamid Kellay
Keyword(s):  
Thin Films ◽  
Elastic Waves ◽  
Open Channel ◽  
Channel Flows ◽  
Next Generation ◽  
Open Channel Flows ◽  
Analogue Gravity ◽  
Flow Phase ◽  
Analogue Experiments ◽  
New System

Here we review the way to build analogue space–times in open channel flows by looking at the flow phase diagram and the corresponding analogue experiments performed during the last years in the associated flow regimes. Thin films like the circular jump with different dispersive properties are discussed with the introduction of a brand new system for the next generation of analogue gravity experiments: flowing soap films with their capillary/elastic waves. This article is part of a discussion meeting issue ‘The next generation of analogue gravity experiments’.

scholarly journals Estimate of the superradiance spectrum in dispersive media

2020 ◽  
Vol 378 (2177) ◽  
pp. 20190236 ◽  
Author(s):  
Theo Torres
Keyword(s):  
Black Hole ◽  
Reflection Coefficient ◽  
Event Horizon ◽  
Vortex Flow ◽  
Theoretical Description ◽  
Dispersive Media ◽  
Next Generation ◽  
Rotating Black Hole ◽  
Analogue Gravity ◽  
The Many

In 2016, the Nottingham group detected the rotational superradiance effect. While this experiment demonstrated the robustness of the superradiance process, it still lacks a complete theoretical description due to the many effects at stage in the experiment. In this paper, we shine new light on this experiment by deriving an estimate of the reflection coefficient in the dispersive regime by means of a Wentzel–Kramers–Brillouin analysis. This estimate is used to evaluate the reflection coefficient spectrum of counter-rotating modes in the Nottingham experiment. Our finding suggests that the vortex flow in the superradiance experiment was not purely absorbing, contrary to the event horizon of a rotating black hole. While this result increases the gap between this experimental vortex flow and a rotating black hole, it is argued that it is in fact this gap that is the source of novel ideas. This article is part of a discussion meeting issue ‘The next generation of analogue gravity experiments’.

scholarly journals Hawking radiation in optics and beyond

2020 ◽  
Vol 378 (2177) ◽  
pp. 20190223 ◽  
Author(s):  
Raul Aguero-Santacruz ◽  
David Bermudez
Keyword(s):  
Hawking Radiation ◽  
Dielectric Material ◽  
Numerical Results ◽  
Next Generation ◽  
Hawking Effect ◽  
Physical Systems ◽  
Analogue Gravity ◽  
General Derivation

Hawking radiation was originally proposed in astrophysics, but it has been generalized and extended to other physical systems receiving the name of analogue Hawking radiation. In the last two decades, several attempts have been made to measure it in a laboratory, and one of the most successful systems is in optics. Light interacting in a dielectric material causes an analogue Hawking effect, in fact, its stimulated version has already been detected and the search for the spontaneous signal is currently ongoing. We briefly review the general derivation of Hawking radiation, then we focus on the optical analogue and present some novel numerical results. Finally, we call for a generalization of the term Hawking radiation. This article is part of a discussion meeting issue ‘The next generation of analogue gravity experiments’.

scholarly journals Analogue gravity on a superconducting chip

2020 ◽  
Vol 378 (2177) ◽  
pp. 20190224 ◽  
Author(s):  
Miles P. Blencowe ◽  
Hui Wang
Keyword(s):  
Black Hole ◽  
Tunnel Junction ◽  
Microwave Circuits ◽  
Acoustic Resonator ◽  
Unruh Effect ◽  
Next Generation ◽  
Analogue Gravity ◽  
Film Bulk Acoustic Resonator ◽  
Josephson Tunnel ◽  
Film Bulk

We describe how analogues of a Hawking evaporating black hole as well as the Unruh effect for an oscillatory, accelerating photodetector in vacuum may be realized using superconducting, microwave circuits that are fashioned out of Josephson tunnel junction and film bulk acoustic resonator elements. This article is part of a discussion meeting issue ‘The next generation of analogue gravity experiments’.

scholarly journals Polariton fluids for analogue gravity physics

2020 ◽  
Vol 378 (2177) ◽  
pp. 20190225 ◽  
Author(s):  
M. J. Jacquet ◽  
T. Boulier ◽  
F. Claude ◽  
A. Maître ◽  
E. Cancellieri ◽  
...  
Keyword(s):  
Event Horizon ◽  
Water Wave ◽  
Fluid Flows ◽  
Two Dimensional ◽  
Next Generation ◽  
Curved Space ◽  
Analogue Gravity ◽  
The Creation ◽  
Bathtub Vortex

Analogue gravity enables the study of fields on curved space–times in the laboratory. There are numerous experimental platforms in which amplification at the event horizon or the ergoregion has been observed. Here, we demonstrate how optically generating a defect in a polariton microcavity enables the creation of one- and two-dimensional, transsonic fluid flows. We show that this highly tuneable method permits the creation of horizons. Furthermore, we present a rotating geometry akin to the water-wave bathtub vortex. These experiments usher in the possibility of observing stimulated as well as spontaneous amplification by the Hawking, Penrose and Zeld’ovich effects in fluids of light. This article is part of a discussion meeting issue ‘The next generation of analogue gravity experiments’.

scholarly journals Optical analogues of black-hole horizons

2020 ◽  
Vol 378 (2177) ◽  
pp. 20190232 ◽  
Author(s):  
Yuval Rosenberg
Keyword(s):  
General Relativity ◽  
Black Hole ◽  
Refractive Index ◽  
Quantum Mechanics ◽  
Hawking Radiation ◽  
Black Hole Horizon ◽  
Next Generation ◽  
Hands On ◽  
Analogue Gravity ◽  
Classical Fields

Hawking radiation is unlikely to be measured from a real black hole, but can be tested in laboratory analogues. It was predicted as a consequence of quantum mechanics and general relativity, but turned out to be more universal. A refractive index perturbation produces an optical analogue of the black-hole horizon and Hawking radiation that is made of light. We discuss the central and recent experiments of the optical analogue, using hands-on physics. We stress the roles of classical fields, negative frequencies, ‘regular optics’ and dispersion. Opportunities and challenges ahead are briefly mentioned. This article is part of a discussion meeting issue ‘The next generation of analogue gravity experiments’.

1477: Durability of Next Generation Flexible Ureteroscopes: Randomized Prospective Study

2004 ◽  
Vol 171 (4S) ◽  
pp. 389-389
Author(s):  
Manoj Monga ◽  
Ramakrishna Venkatesh ◽  
Sara Best ◽  
Caroline D. Ames ◽  
Courtney Lee ◽  
...  
Keyword(s):  
Prospective Study ◽  
Next Generation ◽  
Flexible Ureteroscopes
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