perspective
http://plus.maths.org/content/taxonomy/term/553
enVisual curiosities and mathematical paradoxes
http://plus.maths.org/content/visual-curiosities-and-mathematical-paradoxes
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Linda Becerra and Ron Barnes </div>
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<img class="imagefield imagefield-field_abs_img" width="100" height="100" alt="" src="http://plus.maths.org/content/sites/plus.maths.org/files/abstractpics/5/21%20Oct%202010%20-%2016%3A38/icon.jpg?1287675519" /> </div>
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<p>When your eyes see a picture they send an image to your brain, which your brain then has to make sense of. But sometimes your brain gets it wrong. The result is an optical illusion. Similarly in logic, statements or figures can lead to contradictory conclusions, which we call paradoxes. This article looks at examples of geometric optical illusions and paradoxes and gives explanations of what's really going on.</p>
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<p>When your eyes see a picture they send an image to your brain, which your brain then has to make sense of. But sometimes your brain gets it wrong. The result is an optical illusion. Similarly in logic, statements or figures can lead to contradictory conclusions; appear to be true but in actual fact are self-contradictory; or appear contradictory, even absurd, but in fact may be true. Here again it is up to your brain to make sense of these situations. Again, your brain may get it wrong. These situations are referred to as paradoxes.<p><a href="http://plus.maths.org/content/visual-curiosities-and-mathematical-paradoxes" target="_blank">read more</a></p>http://plus.maths.org/content/visual-curiosities-and-mathematical-paradoxes#commentsarchitectureBanach-Tarski paradoxBarber's Paradoxeschergeometryimpossible objectoptical illusionparadoxPenrose staircasePenrose triangleperspectiveRussell's ParadoxWed, 17 Nov 2010 14:06:13 +0000mf3445337 at http://plus.maths.org/contentThey never saw it coming
http://plus.maths.org/content/they-never-saw-it-coming
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Lewis Dartnell </div>
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<img class="imagefield imagefield-field_abs_img" width="100" height="100" alt="" src="http://plus.maths.org/content/sites/plus.maths.org/files/issue33/features/dartnell_motion/icon.jpg?1104537600" /> </div>
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Most of us have heard of "stealth" - a technology used by the military to disguise craft from enemy radar. But nature's stealth fighters are not so well known - creatures that use motion camouflaging to approach their prey undetected. <b>Lewis Dartnell</b> looks at the vector mathematics behind the phenomenon. </div>
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<div class="pub_date">January 2005</div>
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<h2>Motion camouflaging and nature's stealth fighters</h2>
<p><i>The word "stealth" is often associated with high-tech bombers built to be invisible to enemy radar. This technology works through the aircraft's surface being specially designed and having a covering of radar-absorbent skin that ensures minimal radio waves are reflected back to the enemy radar transmitter.</i></p><p><a href="http://plus.maths.org/content/they-never-saw-it-coming" target="_blank">read more</a></p>http://plus.maths.org/content/they-never-saw-it-coming#comments33motion camouflagingperspectiveSat, 01 Jan 2005 00:00:00 +0000plusadmin2260 at http://plus.maths.org/contentGetting into the picture
http://plus.maths.org/content/getting-picture
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Antonio Criminisi with Rachel Thomas </div>
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<img class="imagefield imagefield-field_abs_img" width="100" height="100" alt="" src="http://plus.maths.org/content/sites/plus.maths.org/files/issue23/features/criminisi/icon.jpg?1041379200" /> </div>
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Imagine stepping inside your favourite painting, walking around the light-filled music room of Vermeer's "The Music Lesson" or exploring the chapel in the "Trinity" painted by Masaccio in the 15th century. Using the <b>mathematics of perspective</b>, researchers are now able to produce three-dimensional reconstructions of the scenes depicted in these works. </div>
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<div class="pub_date">January 2003</div>
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<h2>How a picture is made</h2>
<p>When you look at a photograph of a scene, visual cues - such as converging straight lines, shading effects, receding regular patterns and shadows - are processed by your brain to retrieve consistent information about the real scene. Lines parallel to each other in the real scene (such as the tiles on a floor) are imaged as converging lines in the photograph which intersect at a point called
the <i>vanishing point</i>.<p><a href="http://plus.maths.org/content/getting-picture" target="_blank">read more</a></p>http://plus.maths.org/content/getting-picture#comments23mathematics and artmatrixperspectiveprojective geometryWed, 01 Jan 2003 00:00:00 +0000plusadmin2216 at http://plus.maths.org/content