Apparent Rotation and Jazzing in Leviant's Enigma Illusion

Perception ◽  
10.1068/p5542 ◽  
2007 ◽  
Vol 36 (6) ◽  
pp. 797-807 ◽  
Author(s):  
Kai Hamburger
Keyword(s):  
Apparent Rotation

scholarly journals Symmetric Parsec-Scale Radio Jets in NGC 4261

1998 ◽  
Vol 164 ◽  
pp. 63-64
Author(s):  
Dayton L. Jones ◽  
Ann E. Wehrle
Keyword(s):  
Accretion Disk ◽  
Rotation Axis ◽  
Position Angle ◽  
Narrow Gap ◽  
Apparent Rotation ◽  
Radio Jets

AbstractVLBA observations of NGC 4261 (3C 270) reveal highly symmetric radio structures at both 1.6 and 8.4 GHz. There is little evidence for free-free absorption in the inner few pc, despite the fact that HST imaging shows this galaxy to contain a nearly edge-on disk of gas and dust in its nucleus. However, at our highest resolution we find a narrow gap in emission just east of the radio core which we interpret as evidence for a small (sub-parsec) nearly edge-on accretion disk which is obscuring the base of the counterjet. The position angle of the pc-scale radio axis agrees with the position angle of the VLA-scale jets, which differs from the apparent rotation axis of the nuclear disk seen by HST.

scholarly journals Apparent rotation in three-dimensional space: Effects of temporal, spatial, and structural factors

1988 ◽  
Vol 43 (2) ◽  
pp. 179-188 ◽  
Author(s):  
James T. Todd ◽  
Robin A. Akerstrom ◽  
Francene D. Reichel ◽  
William Hayes
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Structural Factors ◽  
Apparent Rotation ◽  
Space Effects ◽  
Three Dimensional Space

Factors Influencing the Apparent Rotation of a Line on Radially Transformed Backgrounds

Perception ◽  
1983 ◽  
Vol 12 (3) ◽  
pp. 313-322 ◽  
Author(s):  
Nicholas J Wade ◽  
Michael T Swanston ◽  
Hiroshi Ono ◽  
Peter M Wenderoth
Keyword(s):  
Spatial Frequency ◽  
Oblique Line ◽  
Zoom Lens ◽  
Television System ◽  
Vertical Grating ◽  
Apparent Rotation ◽  
Factors Influencing ◽  
Constant Rate ◽  
Orientation Anisotropy ◽  
Angular Subtense

The expansion and contraction of a display consisting of a stationary grating with a superimposed inclined line leads to the apparent rotation of the line. This phenomenon has been investigated in six experiments with the use of a television system with a motorized zoom lens to effect such transformations. The maximum apparent line rotation occurs with the line at 45° to the grating. In experiment 1 a greater magnitude of apparent rotation was found with a vertical grating and an oblique line than vice versa. Zoom-out (contraction) also produced greater rotation than zoom-in (expansion). The orientation anisotropy was not dependent upon the orientation of the display to the retinal meridian (experiment 2): the extent of apparent line rotation was approximately the same with a vertical grating when the head was upright or tilted so that the retinal meridian was at 45°. At a constant rate of zooming, a zoom duration of 2 s produced a larger apparent line rotation than one of 1 s, but it was not influenced by the initial angular subtense of the superimposed line (experiment 3). Neither the spatial frequency of the grating nor the width of the line affected the apparent rotation (experiments 4, 5, and 6). Experiment 5 compared the apparent rotation when the display was zoomed (i) with a fixed surround and (ii) with a surround that also expanded during zooming. The magnitude of rotation in the latter condition was reduced to about 25% of that with a fixed surround. The results are discussed in terms of the discrepancy between the perceived transformations of the background grating and the superimposed line.

scholarly journals Disk Rotation Curves in Triaxial Potentials

1987 ◽  
Vol 127 ◽  
pp. 399-400
Author(s):  
Ortwin E. Gerhard ◽  
Mario Vietri
Keyword(s):  
Rotation Curve ◽  
Rotation Curves ◽  
Apparent Rotation ◽  
Disk Rotation ◽  
Cold Gas

The apparent rotation curve of cold gas in a triaxial potential often differs from that in an axisymmetric system in characteristic ways. The data argue for triaxial bulges in our Galaxy and several others.

Owyheeite from Rivertree, New South Wales

1962 ◽  
Vol 33 (259) ◽  
pp. 315-319 ◽  
Author(s):  
L. J. Lawrence
Keyword(s):  
New South ◽  
New South Wales ◽  
The Other ◽  
Polarization Effects ◽  
Apparent Rotation ◽  
South Wales ◽  
Intimate Association

SummaryOptical and other microproperties of owyheeite Pb5Ag2Sb6S15 are presented and details given of a new locality for this rare sulpho-salt. Apparent rotation of the plane of polarization (3·5°), microhardness (112 V.H.N.), and polarization effects are all very similar to those of the other feather ores, jamesonite and boulangerite. An intimate association with pyrargyrite is further noted.

Subjective Velocity Estimates of Apparent Movement following Visual Stimulation

1971 ◽  
Vol 33 (3_suppl) ◽  
pp. 1029-1030
Author(s):  
John K. Collins
Keyword(s):  
Visual Motion ◽  
Intertrial Interval ◽  
Visual Stimulation ◽  
Apparent Movement ◽  
Motion Aftereffect ◽  
Apparent Velocity ◽  
Stationary Target ◽  
Apparent Rotation ◽  
The Mean

Tracking the apparent movement of a stationary target following prior stimulation by rotation was used to estimate the subjective velocity of the visual motion aftereffect. 10 Ss were given 4 trials each with the apparent velocity averaged over a 10-sec. period following 60 sec. stimulation. The intertrial interval was 5 min. The mean apparent rotation was 1.5° per sec. with SD of 1.6°.

A New Phenomenon of Apparent Movement and its After-Effect

1950 ◽  
Vol 2 (3) ◽  
pp. 119-123 ◽  
Author(s):  
J. A. Deutsch
Keyword(s):  
Apparent Movement ◽  
Spiral Pattern ◽  
Flickering Light ◽  
After Effects ◽  
Apparent Rotation ◽  
Wide Range ◽  
After Effect

It is found that a stationary spiral pattern gives an appearance of movement in a flickering light, and, furthermore, that this apparent rotation gives rise to the same kind of after-effect as a spiral actually rotating. The illusion is obtainable over a wide range of conditions. Detailed results are given in the case of six subjects, but a large number of subjects experienced the illusion. The experimenter has as yet found no one who was not subject to the illusion itself. The after-effects are not universally experienced.

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