macroscopic object
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Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 510
Author(s):  
Les Coleman

The first macroscopic object observed to have come from outside the solar system slipped back out of sight in early 2018. 1I/2017 U1 ‘Oumuamua offered a unique opportunity to test understanding of gravity, planetary formation and galactic structure against a true outlier, and astronomical teams from around the globe rushed to study it. Observations lasted several months and generated a tsunami of scientific (and popular) literature. The brief window available to study ‘Oumuamua created crisis-like conditions, and this paper makes a comparative study of techniques used by cosmologists against those used by financial economists in qualitatively similar situations where data conflict with the current paradigm. Analyses of ‘Oumuamua were marked by adherence to existing paradigms and techniques and by confidence in results from self and others. Some, though, over-reached by turning uncertain findings into graphic, detailed depictions of ‘Oumuamua and making unsubstantiated suggestions, including that it was an alien investigator. Using a specific instance to test cosmology’s research strategy against approaches used by economics researchers in comparable circumstances is an example of reverse econophysics that highlights the benefits of an extra-disciplinary lens.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Autti ◽  
S. L. Ahlstrom ◽  
R. P. Haley ◽  
A. Jennings ◽  
G. R. Pickett ◽  
...  

Abstract The ground state of a fermionic condensate is well protected against perturbations in the presence of an isotropic gap. Regions of gap suppression, surfaces and vortex cores which host Andreev-bound states, seemingly lift that strict protection. Here we show that in superfluid 3He the role of bound states is more subtle: when a macroscopic object moves in the superfluid at velocities exceeding the Landau critical velocity, little to no bulk pair breaking takes place, while the damping observed originates from the bound states covering the moving object. We identify two separate timescales that govern the bound state dynamics, one of them much longer than theoretically anticipated, and show that the bound states do not interact with bulk excitations.


2016 ◽  
Vol 25 (12) ◽  
pp. 1644020 ◽  
Author(s):  
Tsvi Piran

Copious production of gravitational radiation requires a compact source that moves relativistically. Such sources are rare and are found only in extreme cases such as the formation of a black hole in either via a gravitational collapse or via a merger. Noncompact, nonrelativistic objects emit gravitational radiation, however, this emission is extremely weak due to very large value of the Planck energy. The quantum nature of gravitons, namely the fact that a single graviton carries energy of order [Formula: see text] implies that macroscopic objects whose kinetic energy is less than the Planck energy emit gravitons quantum mechanically, emitting a single graviton at a time. This is a unique situation in which a macroscopic object behaves quantum mechanically. While it is impossible to check experimentally this quantum gravitational effect, it might be possible to carry out analogous electromagnetic experiments that will shed light on this macroscopic quantum mechanical behavior.


2014 ◽  
Vol 1035 ◽  
pp. 514-519
Author(s):  
Jing Bo Zhao ◽  
Hong Yao ◽  
Juan Na Jiang

In order to realize the macroscopic objects invisible in the visible region, according to the law of refraction, total internal reflection law and symmetry reduction transformation method, a new type of visible light stealth cloak was designed. The cloak was prepared using the ordinary homogeneous and isotropic glass materials, which can guide the light around the hidden region, and the direction of propagation of light has not changed. Thus the macroscopic object achieve the perfect stealth. The invisible cloak in air environment for arbitrary polarized visible light have stealth features, easy processing, low cost, has potential application value.


2014 ◽  
Vol 14 (3) ◽  
pp. 160-163 ◽  
Author(s):  
Roman Romashko ◽  
Timofey Efimov ◽  
Yuri Kulchin

Abstract Mass of macroscopic object is easily measured by a suitable balance. However, this approach becomes inapplicable if mass of microscopic object is to be determined. Alternative approach for mass measurement is based on using the micromechanical resonator as an inertial balance where oscillation frequency is shifted by small quantities of adsorbed mass. In this work we present experimental results of applying an adaptive interferometry technique based on dynamic hologram recorded in photorefractive CdTe crystal for measuring picogram mass adsorbed on micromechanical resonators with dimensions 215×40×15 μm3. It is also shown that the resonance micro-weighing system based on adaptive interferometer has potential for reducing the threshold of mass detection down to 10-17 g in the case of using a resonator with sub-micron dimensions


Science ◽  
2013 ◽  
Vol 339 (6121) ◽  
pp. 801-804 ◽  
Author(s):  
T. P. Purdy ◽  
R. W. Peterson ◽  
C. A. Regal

2008 ◽  
Author(s):  
C. P. McElhinney ◽  
B. M. Hennelly ◽  
J. B. McDonald ◽  
T. J. Naughton

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