scispace - formally typeset
Topic

Rotation

About: Rotation is a(n) research topic. Over the lifetime, 84289 publication(s) have been published within this topic receiving 599685 citation(s). The topic is also known as: spinning & rotary motion.

...read more

Papers
More filters

Journal ArticleDOI
Roger N. Shepard1, Jacqueline Metzler1Institutions (1)
19 Feb 1971-Science
TL;DR: The time required to recognize that two perspective drawings portray objects of the same three-dimensional shape is found to be a linearly increasing function of the angular difference in the portrayed orientations of the two objects.

...read more

Abstract: The time required to recognize that two perspective drawings portray objects of the same three-dimensional shape is found to be (i) a linearly increasing function of the angular difference in the portrayed orientations of the two objects and (ii) no shorter for differences corresponding simply to a rigid rotation of one of the two-dimensional drawings in its own picture plane than for differences corresponding to a rotation of the three-dimensional object in depth.

...read more

5,025 citations


08 Mar 2001-
TL;DR: A comprehensive theory incorporating both translational and rotational mechanisms may explain the diverse patterns of wing motion displayed by different species of insects.

...read more

Abstract: The enhanced aerodynamic performance of insects results from an interaction of three distinct yet interactive mechanisms: delayed stall, rotational circulation, and wake capture. Delayed stall functions during the translational portions of the stroke, when the wings sweep through the air with a large angle of attack. In contrast, rotational circulation and wake capture generate aerodynamic forces during stroke reversals, when the wings rapidly rotate and change direction. In addition to contributing to the lift required to keep an insect aloft, these two rotational mechanisms provide a potent means by which the animal can modulate the direction and magnitude of flight forces during steering maneuvers. A comprehensive theory incorporating both translational and rotational mechanisms may explain the diverse patterns of wing motion displayed by different species of insects.

...read more

2,133 citations


Journal ArticleDOI
Abstract: Rotation periods are reported for 14 main-sequence stars, bringing the total number of such stars with well-determined rotation periods to 41. It is found that the mean level of their Ca n H and K emission (averaged over 15 years) is correlated with rotation period, as expected. However, there is a further dependence of the emission on spectral type. When expressed as the ratio of chromospheric flux to total bolometric flux, the emission is well correlated with the parameter Pohs/Tc, where Pohs is the observed rotation period and tc(B—V) is a theoretically-derived convective overturn time, calculated assuming a mixing length to scale height ratio a ~ 2. This finding is consonant with general predictions of dynamo theory, if the relation between chromospheric emission and dynamo-generated magnetic fields is essentially independent of rotation rate and spectral type for the stars considered. The dependence of mean chromospheric emission on rotation and spectral type is essentially the same for stars above and below the Vaughan-Preston “gap,” thus casting doubt on explanations of the gap in terms of a discontinuity in dynamo characteristics. Subject headings: Ca n emission — convection — stai

...read more

1,547 citations


Journal ArticleDOI
31 Jan 2000-
TL;DR: Using a focused laser beam, a Bose-Einstein condensate of 87Rb confined in a magnetic trap is stirred and the formation of a vortex is observed for a stirring frequency exceeding a critical value.

...read more

Abstract: Summary form only given. We report on an experiment performed with a gaseous Bose-Einstein condensate, which is analogous to the rotating bucket experiment performed with liquid He. The atoms are confined in a static, cylindrically symmetric Ioffe-Pritchard magnetic trap upon which we superimpose a nonaxisymmetric, attractive dipole potential created by a stirring laser beam. The combined potential leads to a cigar-shaped harmonic trap with a slightly anisotropic transverse profile. The transverse anisotropy is rotated as the gas is evaporatively cooled to Bose-Einstein condensation, and it plays the role of the bucket wall roughness. Pictures taken at various rotation frequencies, after a ballistic expansion of the condensate, clearly show that for fast enough rotation frequencies, we can generate one or several "holes" in the transverse density distribution corresponding to vortices. We discuss our determination of the critical frequency for the single and multiple vortex formation, and we report measurements of the nucleation time and the lifetime of the vortex state.

...read more

1,359 citations



Network Information
Related Topics (5)
Rotation around a fixed axis

4K papers, 52.8K citations

88% related
Angular velocity

13.5K papers, 155.2K citations

87% related
Acceleration

46.8K papers, 453.4K citations

86% related
Inertial frame of reference

5.1K papers, 63.2K citations

85% related
Circular motion

2.4K papers, 28.9K citations

84% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202218
20211,302
20202,629
20193,343
20184,305
20173,921

Top Attributes

Show by:

Topic's top 5 most impactful authors

Rafael A. García

26 papers, 943 citations

Stéphane Mathis

23 papers, 587 citations

Petri J. Käpylä

19 papers, 559 citations

André Maeder

19 papers, 691 citations

S. M. Abo-Dahab

15 papers, 243 citations