Windows 7 Activation Key
auther: date:2013-06-20
sources:http://www.heroninstruments.com/permalink/
Object moves in mysterious ways Watch a line sweep across a screen and its direction of motion is easily perceived.Windows 7 Activation Key But when the same line is viewed through an opening, it appears to change course (see animation above). The perceived motion seems to be determined by the shape of the aperture and the line's orientation, rather than its true behaviour, so why do we experience this effect? According to Dale Purves and his team from Duke University, North Carolina, we're tricked because our brain assumes that the line in the video is a 2D projection originating from a linear object moving in 3D space. Since it's impossible to determine the real world source of the projected line, we rely on a mental model formed by accumulated experience and presume that the object is moving in that direction. Purves and his team tested the theory by using a variety of 3D sources and examining the linear motion produced through different shaped openings. They confirmed that, in each case, the motion we perceive represents the most common scenario. In the circular cutout, the line-segment *geometrically* follows a diagonal path in keeping with the larger line-segment. In the rectangular cutout, it follows a vertical path going down. It's not an optical illusion, it's a geometrical fact--the subtended portion of the line-segment behaves *geometrically* in a different fashion depending on the subtending geometrical cutout, the direction of motion of the larger segment, and the relationship between the two. An easy proof of this is to compute an equation of the center of the subtended line-segment with respect to time and verify that its motion is in keeping with its observed motion in the cutout, which would verify that this is not an optical illusion, but rather a geometrical phenomenon. Said more simply, these are just different lines moving in different ways with and without the apertures. If the lines varied in color along the length then this would be a different story. Then, when looking through the aperture, we would perceive that the line is longer than that being displayed. Sure, in the second case, the diagonal line could be a sliding segment of a longer line moving in a different direction but it isn't. It is simply a short diagonal line sliding down the rectangular aperture.
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