tag:blogger.com,1999:blog-84679752167214165972024-03-21T18:54:12.209-04:00Optical Illusions 4 KidsOptical Illusions for kids of all ages, a safe site for kids to explore the wonders of optical illusions and explanations of optical illusions to calm the brain.Unknownnoreply@blogger.comBlogger14125tag:blogger.com,1999:blog-8467975216721416597.post-82915368982665309292009-03-11T04:50:00.002-04:002009-03-12T05:00:28.697-04:00Time for Optical Illusions 4 Kids<span style="color: rgb(255, 0, 0);font-size:130%;" ></span><blockquote><span style="color: rgb(255, 0, 0);font-size:130%;" >Warning:</span> This page contains some works of "anomalous motion illusion", which might make sensitive observers dizzy or sick. Should you feel dizzy, leave this page immediately.</blockquote><br /><center><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhJ4DqgcUYemOaLReX7muwQuZzT2w7jaceMRju1g8U_FP1JL0THtwflnJrDRue0NHih2jp4LuS5sJGieOmJsBP0nBQwh2b1ywDGvKThtO5sKJapKMjNLDnbANuFSCI12ZgZqPlDH5XuLHU/s1600/walt's+OI4K+clock.JPG" alt="Walt's Clock" border="0" /><br /><a href="http://home.hetnet.nl/%7Edeel3/index.html">Herman Verwaal</a><br />(c)2008<br />Used w/permission</center><br />Here is an anomalous motion illusion that was created for me by Herman. I thought that it was time to share it with y'all. If you don't see the motion, slowly move your eyes around the clock face.Unknownnoreply@blogger.com13tag:blogger.com,1999:blog-8467975216721416597.post-77641763011984675412009-03-10T22:25:00.000-04:002009-03-10T04:40:58.106-04:00Electric Motor Optical Illusion<span style="color: rgb(255, 0, 0);font-size:130%;" ></span><blockquote><span style="color: rgb(255, 0, 0);font-size:130%;" >Warning:</span> This page contains some works of "anomalous motion illusion", which might make sensitive observers dizzy or sick. Should you feel dizzy, leave this page immediately.</blockquote>This illusion was created by my friend, Herman Verwaal of Exloo, Netherland. Herman took up the creation of optical illusions and pop art after he retired. Unfortunately Herman's time on this planet ended last December. He will be missed but not forgotten. Long ago he gave me access to a large library of illusions that he had created he also gave me permission to display them on my blogs. Here is the second that I have featured on this blog.<br /><br /><center><a href="http://www.blogger.com/post-create.g?blogID=8467975216721416597"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_Br3ymsiMDKYlB7p2R-z7Isp-fS-Ir82rlls1b8y1llzFlWXHf5e2JTqdXsBqjTk3aaeti1ZdxlbyOmXOT1XBkQFMb1hCZ27jf8BIrlSNzlkaKylDghPJZPUpDdZGETMrBnLXcL01xak/s1600/electric_motor_optical_Illusion.png" alt="electric motor optical illusion" border="0" /></a><br /><a href="http://home.hetnet.nl/%7Edeel3/index.html">Herman Verwaal</a><br />(c)2008<br />Used w/permission<br /></center><br /><span class="fullpost">This is and example of an anomalous motion optical illusion. Also referred to as peripheral drift optical illusion. As your eyes scan the image the image appears to move. If however you manage to stare at just one point, without moving your eyes, all motion will stop.<br /><br />That is why this is referred to as a peripheral drift illusion. As your eyes drift across the image the motion is seen out of your peripheral vision. A more <span style="color: rgb(255, 0, 0);">detailed explanation</span> of this type of illusion <a href="http://www.psy.ritsumei.ac.jp/%7Eakitaoka/PDrift.pdf">can be found here</a> (as a PDF file).<br /><br /><span style="color: rgb(255, 0, 0);">Printer Alert----> </span>If you have access to a color printer this illusion works on paper too! Print it out to amaze your family or friends. </span>Unknownnoreply@blogger.com7tag:blogger.com,1999:blog-8467975216721416597.post-67070126546907015082009-03-08T22:10:00.008-04:002009-03-08T22:38:57.970-04:00Home Grown Optical Illusions<p> Here is a type of forced perspective optical illusion you can create with your digital camera and family or friends to help you out. The plus using a digital camera is that you can review your shot and adjust the subject as required to get it right.</p><p><span style="font-weight: bold;">Shuttle launch delayed due to hungry giant.</span><br /></p> <center><a href="http://www.flickr.com/photos/toastforbrekkie/234615767/" title="photo sharing"><img src="http://farm1.static.flickr.com/92/234615767_77f8b8a2ba.jpg" class="flickr-photo" alt="optical illusion" /></a><br /><span style="font-size:85%;"><a href="http://www.flickr.com/photos/toastforbrekkie/234615767/">Hot dog!</a><br />Flickr Artist: <a href="http://www.flickr.com/people/toastforbrekkie/">toastforbrekkie</a></span></center><span class="fullpost"><p style="font-weight: bold;">Prenatal vitamins creating larger kids!</p><center><a href="http://www.flickr.com/photos/42873250@N00/126772217/" title="photo sharing"><img src="http://farm1.static.flickr.com/45/126772217_4bb01b5c1b.jpg" class="flickr-photo" alt="optical illusion" /></a><br /><span style="font-size:85%;"><a href="http://www.flickr.com/photos/42873250@N00/126772217/">Giant Julia</a><br />Flickr Artist: <a href="http://www.flickr.com/people/42873250@N00/">dcbprime</a></span></center><br /><span style="font-weight: bold;">First Pocket Monsters now Pocket Friends</span><br /><p> </p> <center><a href="http://www.flickr.com/photos/cmormunkeez/3109277054/" title="photo sharing"><img src="http://farm4.static.flickr.com/3216/3109277054_7e050796ce.jpg" class="flickr-photo" alt="optical illusion" /></a><br /><span style="font-size:85%;"><a href="http://www.flickr.com/photos/cmormunkeez/3109277054/">originality</a><br />Flickr Artist: <a href="http://www.flickr.com/people/cmormunkeez/">pictures and stuffs</a></span></center><br /><span style="font-weight: bold;">Water out of a bottle?</span><br /><br /><center><a href="http://www.flickr.com/photos/ihatefog/2678429333/" title="photo sharing"><img src="http://farm4.static.flickr.com/3059/2678429333_caec2a1787.jpg" class="flickr-photo" alt="optical illusion" /></a><br /><span style="font-size:85%;"><a href="http://www.flickr.com/photos/ihatefog/2678429333/">Pour It On!</a><br />Flickr Artist: <a href="http://www.flickr.com/people/ihatefog/">ihatefog</a></span></center><br /><span style="font-weight: bold;">Her little brother had a growth spurt and is now out of control.</span><br /><br /><center><a href="http://www.flickr.com/photos/gizzleperizzle/3217846113/" title="photo sharing"><img src="http://farm4.static.flickr.com/3310/3217846113_785d50fd98.jpg" class="flickr-photo" alt="optical illusion" /></a><br /><span style="font-size:85%;"><a href="http://www.flickr.com/photos/gizzleperizzle/3217846113/">ARGH</a><br />Flickr Artist: <a href="http://www.flickr.com/people/gizzleperizzle/">robotstrut</a></span></center></span>Unknownnoreply@blogger.com4tag:blogger.com,1999:blog-8467975216721416597.post-637697169793669182007-07-26T00:24:00.005-04:002015-07-16T01:32:25.404-04:00Anomalous Motion Optical IllusionAKA Peripheral Drift Optical Illusion is characterized by anomalous motion that can be observed in peripheral vision.<br />
<span style="color: red; font-size: 130%;"></span><br />
<blockquote>
<span style="color: red; font-size: 130%;">Warning:</span> This page contains some works of "anomalous motion illusion", which might make sensitive observers dizzy or sick. Should you feel dizzy, leave this page immediately.</blockquote>
The above is a serious warning that I borrowed from the master of anomalous optical illusions, Professor Akiyoshi Kitaoka, of Ritsumeikan University, Kyoto, Japan.<br />
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Professor Kitaoka wasn't the first to notice that certain images appear to move if viewed in your peripheral vision. But he has studied the effect and perfected the creation of these optical illusions.<br />
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The first anomalous motion optical illusion is one that I created.<br />
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<img alt="purple nurple optical illusion" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjvcVX_TAaO5vJzoy2qfwOg2SVpeaNe81k7dSqBgWbsYIpUBCkwGUjlmkEGU1XmV6O_euKk03I-VpHc8_Nl9ilhyphenhyphen_Te5iplbKYd-x2qhdaanQR_g3E-0Ap2uGXaLFGS7Fn2VYX_3jXMoE4/s1600/purple-nurple.png" /><br /><br /><span property="dct:title" xmlns:dct="http://purl.org/dc/terms/">Sea Sickness </span></center>
<center>
<span property="dct:title" xmlns:dct="http://purl.org/dc/terms/">(AKA The Purple Nurple)</span><br />by <a href="http://opticalillusions4kids.blogspot.com/2007/07/anomolous-motion-optical-illusion.html" property="cc:attributionName" rel="cc:attributionURL" xmlns:cc="http://creativecommons.org/ns#">Walter Anthony</a><br />is licensed under a <a href="http://creativecommons.org/licenses/by-nc-sa/4.0/" rel="license">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License</a>.<br /><a href="http://creativecommons.org/licenses/by-nc-sa/4.0/" rel="license"><img alt="Creative Commons License" src="https://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png" style="border-width: 0px;" /><br />(c)2007</a>
</center>
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Keep in mind that this is a static image. It is not animated in any way. but as your vision moves back and forth the center area seems to be moving toward the center (contracting) and the outer edges seem to be moving away (expanding) from the center. Also worth noting is that if you fixate on a point in the center and don't move your eyes this anomalous motion will stop.<br />
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The next optical illusion is by the professor himself.<span class="fullpost"> Take a look at these snakes, do they rotate? For an even more amazing experience click on the image. It should open in a new window and take up the entire screen. Remember this image is not animated.</span><br />
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<span class="fullpost"><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgyI6ZuAVFMcdOThaX67wM3AAyd7bJTqwajFauLFhyc3IX6qTF_UHqsy6I3Mvt-RVyquoaof5GORGFrnXaky5Qch4ZWsfbtOErz4EIADZfT0lnMdGDIIscmRwcQ3sKX5LMmkfR1bbGuTMY/s1600-h/rotsnake9.gif" onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" target="_blank"><img alt="" border="0" id="BLOGGER_PHOTO_ID_5171179248898282386" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgyI6ZuAVFMcdOThaX67wM3AAyd7bJTqwajFauLFhyc3IX6qTF_UHqsy6I3Mvt-RVyquoaof5GORGFrnXaky5Qch4ZWsfbtOErz4EIADZfT0lnMdGDIIscmRwcQ3sKX5LMmkfR1bbGuTMY/s800/rotsnake9.gif" style="cursor: pointer;" width="600" /></a><br />"<a href="http://www.psy.ritsumei.ac.jp/%7Eakitaoka/rotsnakee.html">Rotating snakes</a> #9"<br />Each snake appears to rotate.<br />Copyright A.Kitaoka 2004 (October 7)<br />Used w/permission</span></center>
<span class="fullpost"><br /><span style="color: red;">Printer Alert----> </span>If you have access to a color printer this illusion works on paper too! Print out a large version to amaze your family or friends. </span><span class="fullpost"><br /><br /><span style="color: red;">Explanation----></span> Professor Kitaoka has provided a more detailed <a href="http://www.psy.ritsumei.ac.jp/%7Eakitaoka/PDrift.pdf">explanation of the peripheral drift illusion</a> in PDF. </span><br />
<span class="fullpost"><br />Finally the last example is from a friend, Herman Verwaal from Exloo, Netherlands. Since he has retired he has taken to creating optical illusions of all types. Here is one of his anomalous motion optical illusions. Notice the attempted motion this time is side to side (lateral).</span><br />
<center>
<span class="fullpost"><img alt="Moving Bulge 2" border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjeVqJeGGuLRMwu1NwKsB7nVIq46nRjkP5_4p_5BhSKjBxBzKTcpqPKyKH6I_t_Fy06WqqQy8rzv9wMbqiRRKjyoATKi_obinfoOnFP0LrARHTZTyKlRkO0CHQhmNwD4dD9TkcSJ5h3yuw/s800/HV-movingbulge2.png" /><br /><a href="http://home.wanadoo.nl/h.verwaal/">Herman Verwaal</a><br />(c)2008<br />Used w/permission</span></center>
<span class="fullpost"><br /><br />Well there you have examples of three forms of anomalous motion optical illusions.<br /><br />1. Expanding/Contracting<br />2. Rotational<br />3. Lateral<br /><br />A quick thank you to Professor Kitaoka and Herman Verwaal for allowing me to share these illusions with you.</span>Unknownnoreply@blogger.com88tag:blogger.com,1999:blog-8467975216721416597.post-51074531483503712942007-07-18T00:06:00.002-04:002008-02-28T08:30:51.599-05:00Color Contrast Optical IllusionThe below two cubes share some things in common. The creator of this optical illusion states the following. <blockquote>"Despite the fundamental difference in the apparent colour of the 'blue' tiles on top of the left cube, and the 'yellow' tiles on the top of the right cube, all the tiles are in fact physically identical (grey in both cases)."</blockquote><img style="cursor: pointer; float: right;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiiLG8UjC3fYWnpmzPBHgbrp7R4kTHYtjNAoR6aZsA9apTyRuRUQyBngL4XQtWFWxpkI3yyTWp_qAiH6JG8ZHxmdY38rlAsDBikhk4VKDJOfX0UlWR5u8MgUvNRiFtmXyBgn5k29P5vAaU/s200/colour_cube_top-blue-yellow.png" alt="" id="BLOGGER_PHOTO_ID_5090611226654548018" border="0" />I'll take this one step further and let you know that the <a href="http://opticalillusions4kids.blogspot.com/2007/06/color-perception-project-1.html">RGB value</a> for all 11 squares mentioned is exactly the same R:136 G:136 B:136. The blue and yellow squares mentioned are the exact same color as the gray block to the right.<br /><center><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgdNbev1Za5TBik_uA_Jt-mcNxwxoEKUU93F4n3GuCOjxgXb5xmNr58jYI498CrFU528RfqNiHx8YENfz1C27COCohWF2Hh0LlA1RfVnPdgD_hNbaIvtxXYumSzuUsa7Yo1IMkW3MddrAM/s1600/colour_cube_580_wht_bkg.png"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgdNbev1Za5TBik_uA_Jt-mcNxwxoEKUU93F4n3GuCOjxgXb5xmNr58jYI498CrFU528RfqNiHx8YENfz1C27COCohWF2Hh0LlA1RfVnPdgD_hNbaIvtxXYumSzuUsa7Yo1IMkW3MddrAM/s1600/colour_cube_580_wht_bkg.png" alt="" border="0" /></a><br /><a href="http://www.purveslab.net/main/">Dale Purves M.D.</a><br /><a href="http://www.lottolab.org/Home%20page.html">R. Beau Lotto</a><br />(c)2007<br /></center><br />But they are not the only tiles on these cubes that look different but are exactly the same. Can you spot the other tiles that look different but are actually the same exact color?<br /><br /><span class="fullpost"><center><a href="http://opticalillusions4kids.blogspot.com/2007/07/photograph-optical-illusions.html#" onmouseout="MM_swapImgRestore()"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjXTPl2C8ffgYcpQ8WS7hzSXlJoCrB7jSCJz-ug03A70uCKTV59rxdBbiRbyD38wLldNCziUnqOPwiXFaes22FKuZgc-PHY0e8Fbew-i5UGHzLFqRUtD9niMkgzsivqv5_jPXJrCOpuNwM/s1600/colour_cube_580_wht_bkg-reveal.png" name="colourcube" onmouseover="MM_swapImage('colourcube','','https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhjN25Xu0LhX7SpQiX0Qy-vXzGwWAcaD0YRwnqXD-v4ZAvZp_gArRc7p_k_SIt4GjbfqRz03ZPOIHPWmHIKzJiDxsB4K1EFHDnamkYNGcJ2_-_bzc3skjBLE2ZGLop38LyuNwAzZjCBZi0/s1600/colour_cube_580_wht_bkg-a.png',1)" border="0" height="355" width="580" /></a><br /></center><br />The truth is that the optical illusion for tiles numbered 1 are the result of <a href="http://www.purveslab.net/research/explanation/color/color.html">color contrast</a> and the optical illusion for tiles numbered 2 and 3 are the result of <a href="http://www.purveslab.net/research/explanation/brightness/brightness.html">brightness contrast</a>.<br /><br />With that said you must have no doubts that what I'm stating as fact is true. What's that you say? You don't believe it? Ok, OK already, quiet down. I guess we will just have to take the steps needed to prove that I am correct.<br /><br /></span><span class="fullpost"><span style="color: rgb(255, 0, 0);">Project</span>: Proving all the 1, 2, or 3 tiles are </span><span class="fullpost">respectively </span><span class="fullpost">all the same color.<br /><br />There are a few ways you can prove that the tiles are the same color.<br /><br />Before we continue, right click on the top image and open it in a new window. Now you have an image to work with.<br /><br /><span style="font-weight: bold;">1)</span> You can use a graphics program like Photoshop, <a href="http://www.getpaint.net/index2.html">Paint.Net</a>, <a href="http://www.gimp.org/windows/">Gimp</a> or the <a href="http://www.iosart.com/firefox/colorzilla/">Colorzilla</a> extension for Firefox browser.<br /><br />My choice is Colorzilla w/Firefox. Using the eyedropper tool you can determine that the <a href="http://en.wikipedia.org/wiki/RGB">RGB</a> values of the respective tiles are the same, for number 1 tiles the RGB value is R:136 G:136 B:136, number 2 tiles have a RGB value of R:182 G:159 B:14, and number 3 tiles have a RGB value of R:75 G:45 B:138.<br /><br />Not good enough for you, heh? Still not ready to trust that the computer is correct or you don't have an eyedropper tool? Either way you can move on to step 2 or 3 below.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKz990LD45P67UpLmwFgoCf6aBb05cbhaMNY-1MxRpA26HrxEici337Qci51X_l8FN4Qf_i396jqnloW3nTDMDJG4YUUdrzV8vnT36CacKHtOwi0SGWSjfubfHNLEYijrgQUptg3wAq6U/s1600-h/mask_brwn.jpg"><img style="margin: 10px; float: right; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKz990LD45P67UpLmwFgoCf6aBb05cbhaMNY-1MxRpA26HrxEici337Qci51X_l8FN4Qf_i396jqnloW3nTDMDJG4YUUdrzV8vnT36CacKHtOwi0SGWSjfubfHNLEYijrgQUptg3wAq6U/s200/mask_brwn.jpg" alt="" id="BLOGGER_PHOTO_ID_5090650551375110258" border="0" /></a><span style="font-weight: bold;">2)</span> Cut out a cardboard mask.<br /><br />By viewing patches of the squares without the surrounding context, you can remove the effect of the illusion. A piece of cardboard with holes created in the right spots will work as a mask for a computer screen or as a mask for a the printed illusion. Holding up this mask to the image on the screen or printed paper should be enough to convince you. But if you were like my daughter nothing but this next step would do.<br /><br /><span style="font-weight: bold;">3)</span> Print the image and cut out the respective tiles.<br /><br /><span style="color: rgb(255, 0, 0); font-weight: bold; font-style: italic;">WARNING:</span><span style="font-style: italic;"> </span> Do Not use any specialty scissors your mother or wife uses for any kind of crafts, IE. quilting or fabric scissors. Doing this can be hazardous to your short term happiness. When in doubt get permission to use the scissors first.<br /><br />This is another way to isolate the patches from their surrounding context. Cut out each tile along the edges. Remove them. Hold them side by side. Overlap the cut out tiles. Yup they're the same color. No denying it now, is there?<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgaNy7pOIiq4D1Or8y55GhXlagx5TYCgX4Fd6NxKOCKRspk6HuAvEE1cWxlM5mGCpa460IrI8YM3HQ53qG3ZrgyvHoq1oAS6TNa_noE3xF3yjWMxcZPZERWPUPSWUW98eYYU7A0b2OmgU8/s1600-h/scissors.jpg"><img style="margin: 0pt 10px 10px 0pt; float: left; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgaNy7pOIiq4D1Or8y55GhXlagx5TYCgX4Fd6NxKOCKRspk6HuAvEE1cWxlM5mGCpa460IrI8YM3HQ53qG3ZrgyvHoq1oAS6TNa_noE3xF3yjWMxcZPZERWPUPSWUW98eYYU7A0b2OmgU8/s200/scissors.jpg" alt="" id="BLOGGER_PHOTO_ID_5090652896427253890" border="0" /></a><br /><br />Please note that I have heard that some printers have "enhancement" processing that increases the contrast of edges. This can cause the printed squares to have slightly different RGB values. I haven't run into one of these printers yet where the overlapped squares didn't look identical, but your mileage may vary.<br /><br /><span style="font-weight: bold;">4)</span> Of course you could just go to the <a href="http://www.purveslab.net/seeforyourself/">interactive demo</a> that the creator has up on his site. He shows both the color contrast and brightness contrast illusions, plus a few more that will make you think twice about believing what you see.</span>Unknownnoreply@blogger.com14tag:blogger.com,1999:blog-8467975216721416597.post-32118733624055936202007-07-10T16:20:00.000-04:002007-07-27T06:32:08.102-04:00Photograph Optical IllusionsThere are many ways to create an optical illusion. Digitally manipulating a photograph using software such as Photoshop or <a href="http://www.gimp.org/">Gimp</a> creates convincing images, but like special effects in the movies you know they are fake.<br /><br />There are ways to setup true photographic optical illusions without altering or "faking" the image. Take the following actual photo as an example.<br /><br /><center><img style="cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjmLwPam8sqaXsZZseKdNPgYGhGzzMlAnHnEs54LIF60cMzdBZhp2MTBz0XX_zcLs1cDlhJwV3kmWEMqkMVxPEhxXAIiljsB0-bwqRaJLI4xJ_3JhhuijrXoxn8v2uZ-3BAixufE6UnYHE/s1600/Tim_Jensen_chess_anyone_580.jpg" alt="" id="BLOGGER_PHOTO_ID_5085665807409023298" border="0" /><br /><span style="font-size:85%;">Chess Anyone?<br />(c)2002<br /><a href="http://home.comcast.net/%7Etimj351/index.html">Tim Jensen</a><br />Used w/permission</span><br /></center><br />This modern photograph is reminiscent of Sandro Del Prete's famous illusion drawing "Impossible Chess Set" below.<br /><br /><center><img style="cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhyyULnSvD42NH-UQYUywzUdg43P2TVfeXCvsg8aQNLDPJf66tT1rEVlP_YeoI91ghf9R4XMWsTkwmuHm_1XJatGgPvrsmxwgew6FdQ0GaVzeS79M91j173GQmtUHpNo5ZGLTd_M-bP9YA/s1600/delprete_chess.jpg" alt="" id="BLOGGER_PHOTO_ID_5085793964938168690" border="0" /><br /><span style="font-size:85%;">Impossible Chess Set<br /><a href="http://www.illusoria.com/defaultNS1.htm">Sandro Del Prete</a><br />(c) 1975</span><br /></center><br /><br />So how do you think the photo "Chess Anyone?" was accomplished?<br /><br />One key to photographic illusions is the fact that photos are 2 dimensional images of 3 dimensional objects. This means most photo illusions would fall apart if you saw them first hand. If you wish to see the Chess Anyone illusion from an angle that will reveal how it was accomplished <span style="color: rgb(255, 0, 0);">place your mouse over the below reveal screen.</span><span class="fullpost"><br /><center><br /><a href="http://opticalillusions4kids.blogspot.com/2007/07/photograph-optical-illusions.html#" onmouseout="MM_swapImgRestore()"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg8e9DeW24_PF2gr1O4omGJ5_MZKP7RV-kzYy5qfi8I1Awp8JHjbiqunW7bpD-OX8Alfi1IPwmRXLu-GuFlcWpqUArtzUs2Qt7QkLwwQu3kS6o55OabIdfxFq_YEC8adqU4EQHFvWsERiA/s1600/Chess-Setup_blank.jpg" name="chess" onmouseover="MM_swapImage('chess','','https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNAdSp1KwBN0eQogeLKlmzLrRfJWW2vRlNCZTcknlDHZPO3hH9qSY-Zq4FVGgr1XTyCRkTEViu88RVflXlP3SEkTXw4v1FbL-NLem0C90pPI4QmuslarpyOHKQsNM72jGW6KieTIwbG34/s1600/Chess-Setup.jpg',1)" border="0" height="300" width="400" /></a><br /><span style="font-size:85%;">Chess Anyone? Revealed<br />(c)2002<br /><a href="http://home.comcast.net/%7Etimj351/index.html">Tim Jensen</a><br />Used w/permission</span><br /></center><br /><span style="color: rgb(255, 0, 0);">For a complete tutorial</span> on how this photographic optical illusion was done read <a href="http://www.dpchallenge.com/how.php?HOW_ID=27">Tim Jensen's explanation here.</a><br /></span>Unknownnoreply@blogger.com18tag:blogger.com,1999:blog-8467975216721416597.post-22258677950957003412007-07-02T14:38:00.000-04:002007-07-24T04:22:09.429-04:00Muller-Lyer Optical IllusionThe Muller-Lyer illusion is a size constancy illusion. In this illusion, the red and the blue lines below are the same length, but due to the effects of the arrows the red line appears longer.<br /><br /><center><img style="cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgsq06B6CEHweVpMNQgj46H4Tb_j1AQ7bDobF1QrDorV0pkjiMt_J_lyCVMXFDH3ZIVVXMmAtb3OM6LKmehgFXhuzZ5n1oXF8kbRBS5dOGdiamp398JaVGjzFuHi-v9EO3aMbUqBjh73J4/s1600/muller-lyer-wa.png" alt="muller-lyer optical illusion" id="BLOGGER_PHOTO_ID_5083244420811655394" border="0" /><br /><span style="font-size:85%;">The red and blues lines are both 170 pixels long</span><br /></center><br /><br />The illusion has been well studied since it was described by German psychiatrist Franz Carl Muller-Lyer in 1889. However, there is no certain explanation for the apparent difference in the perception of the lengths.<br /><br /><center><img style="cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5Y-yKl5W2dY0Wq_vt5W3Y-xQhtrVHAQcinYtRT-SGf7nh7hn5MY4DLfHoyisXHdOxu8JRfTd-I1OLiLhXC5QJ84ugORglJl5zkPGxRZ3mPZRwV_5IMObz2CI83g3K0ZU9iPGKfL26cdk/s1600/muller-lyerpic.png" alt="muller-lyer optical illusion" id="BLOGGER_PHOTO_ID_5083264418179385618" border="0" /><br />Muller-Lyer<br />1889<br /></center><br />Muller-Lyer attempted to explain the illusion he had discovered as follows: "the judgment not only takes the lines themselves, but also, unintentionally, some part of the space on either side."<br /><br />One of the better explanations I've read comes in the form of a <a href="http://www.mind.duke.edu/files/sites/purves/pub/1181623288.pdf">PDF file</a> from Catherine Q. Howe and Dale Purves of the <a href="http://www.mind.duke.edu/">Center for Cognitive Neuroscience</a>, Duke University.<br /><br /><span style="color: rgb(255, 0, 0);">Below is an amazingly strong illusion that combines both the <a href="http://opticalillusions4kids.blogspot.com/2007/06/ponzo-optical-illusion.html">Ponzo</a> and Muller-Lyer optical illusions.</span><span class="fullpost"><br /><center><br /><a href="http://illusionsetc.blogspot.com/2006/07/ponzo-optical-illusion.html#" onmouseout="MM_swapImgRestore()"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhVJEBN0itwnljRBnNNrD_lH1ajwCIsjkg6vey69gCKBTOEC8EpRdlDzZGkyDInw4_oeoaS08ps6ghhfEqzeiuKP-GrnGgTybnbEz1-6QvzMIrwfhgQ3XP5lZ1N2DZFU2m-4roFB_VVglc/s1600/muller_lyer_tickets.png" name="muller-lyer" onmouseover="MM_swapImage('muller-lyer','','https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiuhRT1y8I-osoXgsNbg_2v6g-vmc-J09ZNus2R45XEKo6VR3j4QJthHOxCDu3BkcjL7aRrorKwh-crBezYreOPS4lfp18y9Wsp2XCRH4W2OdfRdq8UZPwx2Y9xUeCuIgcL6xsHAQpklAo/s1600/muller_lyer_tickets-2.png',1)" border="0" height="292" width="447" /></a><br /><a href="http://www.planetperplex.com/en/item85"><span style="font-size:85%;">Source</span></a><br /><span style="font-size:85%;">The two red vertical lines are the same length.<br />Placing your pointer over the image will aid you in exposing this illusion</span>.<br /></center><br />In the tickets image above the perspective of distance lends itself to the <a href="http://opticalillusions4kids.blogspot.com/2007/06/ponzo-optical-illusion.html">Ponzo optical illusion</a>, the angles at the end of each line add to this the Muller-Lyer illusion, combined they create a very effective optical illusion.<br /><br /><br /><span class="fullpost"><span style="font-weight: bold; color: rgb(255, 0, 0);">Project</span>: Create your own illusion. See how the following variations might effect the relative strength of this illusion.<br /><br />Does changing the color of the background change the effect?<br />Does changing the color of the arrows change the effect?<br />Try changing the color of the equal lines,<br />is there any combination of colors that is stronger then the others?<br />Try fat lines. Try skinny lines. Does the thickness of the lines affect this illusion?<br />Does the distance from which you view the illusion change the illusion?<br /><br />What can you conclude, if anything, about how we perceive things from this project?</span></span>Unknownnoreply@blogger.com5tag:blogger.com,1999:blog-8467975216721416597.post-28836527110725785312007-07-01T08:42:00.000-04:002007-07-24T04:22:00.595-04:00Ambiguous Rabbit or Duck Optical Illusion<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiGjvvkkHRr4Y89F28U1s1oBMKwyF1wFNEjZ6l6ne7Kk5MxE5qn99HdAFUCzAJuK3HJOkSxnLscGAztRimApwfMOnJINPjJm2HciW71VjzxMyiAIhRuNeqK_2oRi-Kk-4HfvvaD0ncbaaY/s1600-h/JastrowDuckFliegende.jpg"><img style="margin: 0pt 0pt 10px 10px; float: right; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiGjvvkkHRr4Y89F28U1s1oBMKwyF1wFNEjZ6l6ne7Kk5MxE5qn99HdAFUCzAJuK3HJOkSxnLscGAztRimApwfMOnJINPjJm2HciW71VjzxMyiAIhRuNeqK_2oRi-Kk-4HfvvaD0ncbaaY/s320/JastrowDuckFliegende.jpg" alt="" id="BLOGGER_PHOTO_ID_5078089791778699890" border="0" /></a>There is a whole section of illusions that are ambiguous. This means that the image is open to more than one interpretation.<br /><br />One of the oldest ambiguous figures is the "Duck or Rabbit" This illusion first appeared in the October 23rd issue of Fliegende Blatter (a German humor magazine) in 1892. <span style="font-size:85%;"><a href="http://socrates.berkeley.edu/%7Ekihlstrm/JastrowDuck.htm">source</a>.</span><br /><br /><br />The interesting thing about this illusion is that it is frequently credited to <a href="http://psych.wisc.edu/jastrow.html">Joseph Jastrow</a> 1899. Joseph Jastrow is an American psychologist who was the first to note this image in his work. He used the duck-rabbit figure to make the point that perception is not just a product of the stimulus, but also of mental activity – that we see with the mind as well as the eye - <span style="font-size:85%;"><a href="http://socrates.berkeley.edu/%7Ekihlstrm/JastrowDuck.htm">source</a></span>.<br /><br />Jastrow's Cartoon (1899)<br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi80wChd2kb4dPFUTRsHRVTn-cjbxZm-nHnItxVzx035NGOdCaMFWzSldAHKK6Zyd1-P8RPraTPQqk3KxkfXaneUVEMhmQ_vfq7zMdYCRwvJ3HIccO_zI-MidnNM93LPNwWqkzKKM5LIqo/s1600-h/JastrowDuckRabbit.jpg"><img style="margin: 0pt 10px 10px 0pt; float: left; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi80wChd2kb4dPFUTRsHRVTn-cjbxZm-nHnItxVzx035NGOdCaMFWzSldAHKK6Zyd1-P8RPraTPQqk3KxkfXaneUVEMhmQ_vfq7zMdYCRwvJ3HIccO_zI-MidnNM93LPNwWqkzKKM5LIqo/s320/JastrowDuckRabbit.jpg" alt="" id="BLOGGER_PHOTO_ID_5078086450294143586" border="0" /></a><br />The truth though is that while Jastrow used his image in 1899 it had appeared in print at least twice before both times in 1892.<br /><br />Jastrow's 1899 cartoon version was based on one originally published in Harper’s Weekly (November 19, 1892, p. 1114). The Harper's cartoon, in turn, was based on the original in Fliegende Blatter.<br /><br /><span style="color: rgb(255, 0, 0);">Below is a new version of this old favorite<span style="font-weight: bold;">...</span></span><br /><br /><span class="fullpost">The photographer found this version during a visit to the Ripley's Believe It or Not! museum in Branson, Missouri.<br /><br />What do you see a duck (looking left) or a rabbit (looking right). If you slide your mouse over the image the photo will rotate giving you a slightly differ perspective.<br /><center><br /><a href="http://illusionsetc.blogspot.com/2007/01/duck-or-rabbit-illusion.html#" onmouseout="MM_swapImgRestore()"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjSXt3r8dRvnJvMSj4HuuxW852UJi4ihSWfXSmgvZ2hxCdGT5MWxvwBaD0y7RHcAAMl31BKH4uy8_b6s4nIN8WgmVgHoHYSIyP5LLTPQr4wQ98Fdc7o5H4VHkwYJ8AaTEuf77lAyxBW1_Q/s400/duck-rabbit-R.png" name="rabbit" onmouseover="MM_swapImage('rabbit','','https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiJnKvSPqufumtClPQZzN9aq0zN_qmjDUrhZifFdKdN3nTvx5jrnXdX2bmNgS_901uokUF78eNtFp7kVxoeesRHqzCRUsJVmfoEDPkgS44QOcWCsjKiLYmHEY-FGnJmcGiyMtp4GNJ2CAQ/s400/duck-rabbit-D.png',1)" border="0" height="400" width="387" /></a><br />Flickr Artist: <a href="http://www.flickr.com/photos/dropped_stitch/565125291/" title="Link to Dropped_Stitch's photos">Dropped_Stitch</a><br /></center><br /><br />So what did you see in this image a duck or a rabbit? Which version above is most effective for you?<br /><br />There are an endless variety of this type of illusion. What other ambiguous optical illusions have you seen?</span>Unknownnoreply@blogger.com6tag:blogger.com,1999:blog-8467975216721416597.post-8531251733244760382007-06-30T06:35:00.002-04:002011-02-03T21:37:54.245-05:00Watercolor Optical IllusionThis is an example of the watercolor effect. This effect was first demonstrated by Baingio Pinna in 1987.<br /><br />Simply put The watercolor effect is perceived when a dark (e.g., purple) contour is flanked by a lighter chromatic contour (e.g., orange). Under these conditions, the lighter color will assimilate over the entire enclosed area.<br /><br />What does that mean? Take a look at the below image. You see 9 distinct squares. The center of each square looks white but the outer area of each square has taken on a watercolor shade, pink, green, yellow, blue etc...<br /><br /><center><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhxmS-ZFqMbtHI3P1hYq2yMHGiGhCjgG3AxBJ8ucAvxDSGyrHeE9VGJF8-MsyOYcRW2m80wugSfVMSgmYLPmtMIa9OSff0hoNVURREMICw5nCJ-s9bFGf8VVwIWhfqGBUGpPuvuxE31SDs/s1600/watercolor.png" alt="watercolor optical illusion" border="0" /><br />Tic-Tac-Toe Board<br />(c)Walt Anthony<br /><span style="font-size:85%;"><span style="font-size:78%;">Created from <a href="http://www.psy.ritsumei.ac.jp/%7Eakitaoka/cataloge.html">samples</a><br />provided by <a href="http://www.psy.ritsumei.ac.jp/index-e.html">Akiyoshi Kitaoka</a></span><br /></span></center><br />The truth is that aside from the squiggly lines the only color here is white. The outer ring and the inner square are pure white. <span class="fullpost"><br /><br /><span style="color: rgb(255, 0, 0);">Prove It</span>: You can prove this by using the eye dropper tool in either of the following free graphics programs <a href="http://www.getpaint.net/index2.html">Paint.Net</a> or <a href="http://www.gimp.org/windows/">Gimp</a> or you can use the eye dropper tool in the free <a href="http://www.iosart.com/firefox/colorzilla/">Colorzilla</a> extension for Firefox browser. When you use these tools you will find that RGB value of everywhere on this image that is not a squiggly line is R:255 G:255 B:255 or #FFFFFF.<br /><br /><span style="color: rgb(255, 0, 0);">Print out</span> this image and slide it into a plastic document protector. Now use an earasable marker and you have a reusable optical illusion Tic-Tac-Toe board.<br /></span>Unknownnoreply@blogger.com11tag:blogger.com,1999:blog-8467975216721416597.post-14156161357330276472007-06-29T09:12:00.000-04:002007-07-24T04:22:09.429-04:00Ponzo Optical IllusionThe Ponzo illusion is an optical illusion that was first demonstrated by the Italian psychologist <a href="http://links.jstor.org/sici?sici=0002-9556%28196012%2973%3A4%3C645%3AMP1%3E2.0.CO%3B2-4&size=LARGE&origin=JSTOR-enlargePage">Mario Ponzo </a>(1882-1960) in 1913. He suggested that the human mind judges an object's size based on its background.<br /><br />The typical example of this is the figure below. This is the typical railroad track scheme usually used to represent this illusion. The vertical lines appear to go off into the distance like train tracks. This gives us the impression that the line in the distance is larger then the line that appears to be nearer to the viewer.<br /><h2 align="center"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEir2ItBdGYyXZ8igwzFcBkSl36mehCMxb0wfN9YSFN8aDWEshEW_x6C42nwSCVVJKRH7xMhKo631-utKfqPkH0gy1JzA98KTG0gktqIVb845e-VdemT8XFZvroujcj45hwd7R36O0emlas/s400/250px-Ponzo_Illusion.jpg" alt="Ponzo Optical Illusion" /></h2><div style="text-align: center;">Mario Ponzo<br />1913<br /></div><br />Seeing this illusion against a great real photo backdrop can be amazing. Most of the time people pick train tracks. <span style="color: rgb(255, 0, 0);">Below is an outstanding photo that presents this optical illusion slightly different<span style="font-weight: bold;">...</span></span><br /><br /><span class="fullpost">The two red lines (or three if you move your mouse over the image) below are duplicates, they are the exact same size. Which image is more convincing the one with two lines or the one with three lines?<br /><center><br /><a href="http://opticalillusions4kids.blogspot.com/2007/06/ponzo-optical-illusion.html#" onmouseout="MM_swapImgRestore()"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhuwumcvATRxTMBSJyH4zF9DsMXiKiPAMWRMpE8_3B3WD_HVxGnkCuI-rCB0gTuSHaYGJGJrWMYI_Kwn_qFRfoV-o3kzPYXUCd6-M_yG1od_2ZXxUgRdvT-AvPUE1nrRlXZzAYHSZUXo-k/s1600/Ponzo_optical_illusion-2.jpg" name="ponzo" onmouseover="MM_swapImage('ponzo','','https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjs9r45HbxIYLd5GgKsRLqE4Bo-LK78Z757ytvt-WIp4XEV7OIHse33DKdqoZPtpJ_j_iCp7W2pLfGanBYPN3H4TnvR09VrMD4RUMzljyYf2P-xev2hgeZfdQcNMWcg-nx0Xb7xcyKYgDs/s1600/Tube_Ponzo_optical_illusion.jpg',1)" border="0" height="566" width="580" /></a></center><div style="text-align: center;"><span style="font-size:85%;">Ponzo Illusion<br />(c) 2006 Walt Anthony</span></div><br /><span style="font-weight: bold;"><span style="color: rgb(255, 0, 0);">Project</span>:</span> Create your own illusion. Here is a suitable image of <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg9Y7Vd8B1kvDrTSCUKHUdUE3yPh06hcl1eDgcVJIvjV0tuhfnf_6Eh694AZMUv-WcqPzKIOiIyWqStg3N5Ha6rK1niOLYmvlByX559cWzqrQGY5eV545lYM8Bqm7ydJVGObAWmvcsP1tI/s1600/ponzo_blank.png" target="_blank">train tracks</a> (right click and select "save target as" or "save link as" depending on your browser). You can use Windows Picture and Fax viewer to print it out.<br /><br />Now that you have it printed try and create your own illusion.<br /><br />Use 2 Popsicle sticks painted red or just draw red lines with a marker.<br />Does changing the color change the effect?<br />Does using two different colors alter the illusion?<br />Try fat and skinny lines. Does the thickness of the lines affect this illusion?<br />Vary the distance between the lines, does this change the effect?<br />Is a three dimensional Popsicle stick as effective as 2 dimensional red line?<br />Does the distance from which you view the illusion change the illusion?<br /><br />What can you conclude, if anything, about how we perceive things from this project?<br /></span>Unknownnoreply@blogger.com38tag:blogger.com,1999:blog-8467975216721416597.post-87595504973697011852007-06-28T07:24:00.001-04:002007-07-24T04:22:09.430-04:00Hering Optical IllusionThis optical illusion was discovered by the German physiologist Ewald Hering in 1861. The two blue lines are both straight and parallel to each other. If you are like most folks you may see things differently. The lines in fact may look as if they are bowed outward.<br /><br /><center><a href="http://opticalillusions4kids.blogspot.com/2007/06/hering-optical-illusion.html#" onmouseout="MM_swapImgRestore()"><img src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiyQ8MeNhQrh3mwF7Z9UW0HRYLXyKoF-Gu26bzwM7WPX_z0kMNzqp97npx_dOHevsr26B3eabQvdkZ6ixaqdjrok-NqHudP6dekrC1j6HnTJiT3PlH2zF7zNScn9rpoNYuKTcDbflEFmR4/s1600/herings_red.jpg" name="hering" onmouseover="MM_swapImage('hering','','https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh7y_DwPMPNZOaq5oQPUrRWYgABJy1UnPE4frGyepvQM0_ciAyWfNO0Xl5NqOWOKL4H4ZLLXxyg6SCdgSN-z10GkBajbOKau357Hjf1kbTjeR7KO858yGy2Cd_0MPwEx7xS1d2IhtrQsEc/s1600/herings-2-red.png',1)" border="0" height="469" width="439" /></a><br />Ewald Hering<br />1861<br /></span></center><span class="fullpost"><br />The distortion is produced by the lined pattern on the background, that simulates a perspective design, and creates a false impression of depth. If you pass your mouse over the image the background lines will be removed and you can see for yourself that the blues lines are definitely straight.<br /><br /><span style="font-weight: bold; color: rgb(255, 0, 0);">Project</span>: Create your own illusion. Select a sheet of paper and place a dot in the center of the sheet. Now draw 10 lines through the center, mimicking as close as you can the background of the above illusion. Now on a sheet of clear document protector draw your two vertical lines.<br /><br /></span><span class="fullpost">Increase the amount of background lines to 18. Does that affect the illusion?</span><br /><span class="fullpost">Does changing the color of the background change the effect?<br /></span><span class="fullpost">Does changing the color of the background lines change the effect?</span><br /><span class="fullpost">Does using two different colors for the vertical lines alter the illusion?<br />Try fat lines. Try skinny lines. Does the thickness of the lines affect this illusion?<br />Vary the distance between the vertical lines, does this change the effect?<br />Does the distance from which you view the illusion change the illusion?<br /><br />What can you conclude, if anything, about how we perceive things from this project?<br /></span>Unknownnoreply@blogger.com2tag:blogger.com,1999:blog-8467975216721416597.post-53568891348659917852007-06-27T05:37:00.001-04:002007-07-24T04:22:09.430-04:00Checker Shadow Optical IllusionThis is the Checker Shadow Optical Illusion. It was developed by Edward H. Adelson of the <a href="http://web.mit.edu/persci/index.html">Perceptual Science Group</a> at <a href="http://web.mit.edu/">MIT</a>. The interesting thing about the below optical illusion is that square A is the exact same shade of gray as square B.<br /><br />One way to identify a color is by it's <a href="http://en.wikipedia.org/wiki/RGB"><span style="font-weight: bold; color: rgb(255, 0, 0);">R</span>ed, <span style="font-weight: bold; color: rgb(0, 153, 0);">G</span>reen, <span style="font-weight: bold; color: rgb(51, 51, 255);">B</span>lue</a> values or <span style="color: rgb(255, 0, 0); font-weight: bold;">R</span><span style="color: rgb(0, 153, 0); font-weight: bold;">G</span><span style="color: rgb(51, 51, 255); font-weight: bold;">B</span> for short. When written for 24 bit truecolor <span style="color: rgb(255, 0, 0); font-weight: bold;">R</span>:0 <span style="color: rgb(0, 153, 0); font-weight: bold;">G</span>:0 <span style="color: rgb(51, 51, 255); font-weight: bold;">B</span>:0 is black and at the other end of the spectrum <span style="color: rgb(255, 0, 0); font-weight: bold;">R</span>:255 <span style="color: rgb(0, 153, 0); font-weight: bold;">G</span>:255 <span style="color: rgb(51, 51, 255); font-weight: bold;">B</span>:255 is white. The other <a href="http://en.wikipedia.org/wiki/Color_depth">16 million</a> or so colors fall somewhere in between. Squares A and B below each have the same <span style="color: rgb(255, 0, 0); font-weight: bold;">R</span><span style="color: rgb(0, 153, 0); font-weight: bold;">G</span><span style="color: rgb(51, 51, 255); font-weight: bold;">B</span> value of <span style="color: rgb(255, 0, 0); font-weight: bold;">R</span>:120 <span style="color: rgb(0, 153, 0); font-weight: bold;">G</span>:120 <span style="color: rgb(51, 51, 255); font-weight: bold;">B</span>:120.<br /><br /><center><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgxmQcIgJw3YJtvNpwhL9AsnS4I90hHoKVZ2L9vuRoRtqXruL_L5-uGcv_eFM0hTDs4IM1Bc3jYlOZKfmhvcpz5D_XdKsU-WIrfndnQ2669DY-YZxxjU23x7ggxDyPlwXY1fLJwFmjNpao/s1600-h/checkershadow_illusion4full.jpg"><img style="cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjH45Xn4jMOX6ElHcMOOollDbufDqQjxNu9g36HLpbEr78jK_wznUm-4l61mEpMxQP9aLZHLpV6w-9qhzB6kKlMjf4t60G9TAeFPjsH9l9jaVgvrJ3Q5aDsYekhIKrlsJoOEO9PHeB4IW0/s400/checkershadow_illusion_400.png" alt="" id="BLOGGER_PHOTO_ID_5080676034663614178" border="0" /></a></center><br />So now that I said it is true you have all obviously accepted the fact that square A and square B are indeed the exact same shade of gray, right? I mean if it is on the internet it must be true. Would it be easier if you could prove it to yourself and any skeptics you might run into (like Mom and Dad or that annoying sibling). Continue on and we'll get around to proving my statements correct.<br /><span class="fullpost"><br /><span style="color: rgb(255, 0, 0);">Project</span>: Proving square "A" is the same shade of gray as square "B".<br /><br />There are a few ways you can prove that the 2 squares are the same shade.<br /><br />Before we continue, right click on the image and open it in a new window. Now you have a giant image to work with.<br /><br /><span style="font-weight: bold;">1)</span> You can use a graphics program like Photoshop, <a href="http://www.getpaint.net/index2.html">Paint.Net</a>, <a href="http://www.gimp.org/windows/">Gimp</a> or the <a href="http://www.iosart.com/firefox/colorzilla/">Colorzilla</a> extension for Firefox browser.<br /><br />My choice is Colorzilla w/Firefox. Using the eyedropper tool you can determine<br />that the RGB values of the grays in both square A and square B are 120-120-120.<br />Not good enough for you, heh? Still not ready to trust that the computer is correct or you don't have an eyedropper tool? Either way you can move on to step 2 or 3 below.<br /><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg3ufMrFtyT1RNOJPz0asdOodUtIyEYDKZohgr6QOsNx2UU8DGEYL_BsisrriQTTal7egn5v_l342wxSNVeLcuBQ0j8b5EwsYJg6gr0Bj3EmRJF29La6xy6WAdnkKTTnSmf2NPvNKITeFM/s1600-h/mask.jpg"><img style="margin: 0pt 0pt 10px 10px; float: right; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg3ufMrFtyT1RNOJPz0asdOodUtIyEYDKZohgr6QOsNx2UU8DGEYL_BsisrriQTTal7egn5v_l342wxSNVeLcuBQ0j8b5EwsYJg6gr0Bj3EmRJF29La6xy6WAdnkKTTnSmf2NPvNKITeFM/s200/mask.jpg" alt="" id="BLOGGER_PHOTO_ID_5080695370606380802" border="0" /></a><span style="font-weight: bold;">2)</span> Cut out a cardboard mask.<br /><br />By viewing patches of the squares without the surrounding context, you can remove the effect of the illusion. A piece of cardboard with two holes created in the right spots will work as a mask for a computer screen or as a mask for a the printed illusion. Holding up this mask to the image on the screen or printed paper should be enough to convince you. But if you were like my daughter nothing but this next step would do.<br /><br /><br /><span style="font-weight: bold;">3)</span> Print the image and cut out the squares.<br /><br />This is another way to isolate the patches from their surrounding context. Cut out each square along the edges. Remove them. Hold them side by side. Overlap the cut out<br />squares. Yup they're the same shade of gray. No denying it now, is there?<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjLjCbzkJYvQ99rXzA6K1rim5jhFqNddZ0KXZCwgWM4tZnpVDTHUAOiMxvmenwkR0orYPnQMfUdHJIiWwNy1LL1vqZYL0wcWW21Xvyh7tjY_CsdEIxv6ie37hfP9jfK3zltbv0DbaXFTXc/s1600-h/Cut_out.gif"><img style="margin: 10px; float: left; cursor: pointer;" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjLjCbzkJYvQ99rXzA6K1rim5jhFqNddZ0KXZCwgWM4tZnpVDTHUAOiMxvmenwkR0orYPnQMfUdHJIiWwNy1LL1vqZYL0wcWW21Xvyh7tjY_CsdEIxv6ie37hfP9jfK3zltbv0DbaXFTXc/s200/Cut_out.gif" alt="" id="BLOGGER_PHOTO_ID_5080697341996369682" border="0" /></a><br /><br />Please note that I have heard that some printers have "enhancement" processing that increases the contrast of edges. This can cause the printed squares to have slightly different values of gray. I haven't run into one of these printers yet where the overlapped squares didn't look identical, but your mileage may vary.<br /><br /><span style="font-weight: bold;">WHY you ask? </span>You might have come to terms with the fact that the two squares are the same shade of gray, but how does this optical illusion work? The creator of the illusion has an <a href="http://web.mit.edu/persci/people/adelson/checkershadow_description.html">explanation here</a>.<br /><br /></span>Unknownnoreply@blogger.com3tag:blogger.com,1999:blog-8467975216721416597.post-58401563390303380772007-05-01T23:46:00.002-04:002008-03-09T23:50:35.333-04:00Privacy PolicyOptical Illusions 4 Kids (OI4K) is an educational website about optical illusions. While we encourage children to engage in our website, we also wish to educate parents and kids about issues of privacy when visiting our site.<br /><br /><strong><span style="color: rgb(0, 0, 0);">What Information is Collected?</span></strong><br />Optical Illusions 4 Kids (OI4K) currently does not collect any personally identifiable information from children who visit the site. Nor is any personal information collected from IP addresses, log files or other backend systems. OI4K may collect certain aggregate data, such as the number of users who visit the Web site, and may share that data with partners and advertisers.<br /><br />If OI4K adds features that involve the collection of personal information (such as electronic greeting cards, newsletters or bulletin boards), these features will comply with the Children's Online Privacy Protection Act of 1998 ("COPPA"), and there will be a parental consent process in place. This Privacy Statement will be updated if these features are added, so please periodically review this page<br /><br /><span style="font-weight: bold; color: rgb(0, 0, 0);">E-mail — collection of personal information</span><br />We will only record your e-mail address if you send us a message. It will only be used for the purpose for which you have provided it and will not be added to a mailing list. We will not use your e-mail address for any other purpose, and will not disclose it, without your consent.<br /><p><strong><span style="color: rgb(0, 0, 0);">Cookies</span></strong><br />Cookies are used to gather basic tracking information and to monitor the presentation of advertisements and are placed on your hard drive by many major websites. 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By following a link to an external site you will be leaving the OI4K website.<br /></p><p>When last reviewed, the websites linked from OI4K seemed suitable for you to visit, but that may have changed; if you have any difficulties or concerns with any linked materials, <a href="mailto:illusions4kids@gmail.com">please let us know</a>.</p><span style="color: rgb(0, 0, 0); font-weight: bold;">Sponsors</span><br />Some of our advertising partners may use cookies and web beacons on our site. Our advertising partners include Google Adsense, Chitka.<br /><p><br />These third-party ad servers or ad networks use technology to the advertisements and links that appear on OI4K send directly to your browsers. They automatically receive your IP address when this occurs. Other technologies ( such as cookies, JavaScript, or Web Beacons ) may also be used by the third-party ad networks to measure the effectiveness of their advertisements and / or to personalize the advertising content that you see.<br /><br />OI4K has no access to or control over these cookies that are used by third-party advertisers.<br /><br />You should consult the respective privacy policies of these third-party ad servers for more detailed information on their practices as well as for instructions about how to opt-out of certain practices. OI4K's privacy policy does not apply to, and we cannot control the activities of, such other advertisers or web sites.<br /><br />If you wish to disable cookies, you may do so through your individual browser options. More detailed information about cookie management with specific web browsers can be found at the browsers' respective websites.<br /><br /></p><p><span style="font-weight: bold; color: rgb(0, 0, 0); font-style: italic;">Kids </span><br />We can make sure that you're safe on Optical Illusions 4 Kids (OI4K), but we can't watch out for you on other Web sites. So when you leave OI4K to go to another Web site, check with your parents -- especially if that Web site asks for any personal information about you or your family.<br /><br />Let your parents know every time someone asks for your personal information online, even when it's a friend. Your parent will tell you when it's OK to give out your personal information. It's better to be safe than sorry, so always ask first!<br /><br />Most of all, we want you to have fun and stay safe online!</p><span style="font-weight: bold; color: rgb(0, 0, 0);">Other Questions? Click </span><a style="font-weight: bold; color: rgb(0, 0, 0);" href="mailto:illusions4kids@gmail.com">here to send an e-mail</a><span style="font-weight: bold; color: rgb(0, 0, 0);">.</span>Unknownnoreply@blogger.com3tag:blogger.com,1999:blog-8467975216721416597.post-90079007985189963582007-04-01T03:13:00.001-04:002020-10-15T16:04:09.765-04:00Links<a name="top"></a><table align="center" border="2" cellpadding="3" cellspacing="5" style="font-weight: bold;"><tbody><tr> <td bgcolor="#ffffcc"><a href="http://opticalillusions4kids.blogspot.com/2007/04/links.html#illusions">Optical Illusions</a></td> <td bgcolor="#ffffcc"><a href="http://opticalillusions4kids.blogspot.com/2007/04/links.html#3d">Blogs
</a></td> <td bgcolor="#ffffcc"><a href="http://opticalillusions4kids.blogspot.com/2007/04/links.html#science">Science and stuff</a></td> <td bgcolor="#ffffcc"><a href="http://opticalillusions4kids.blogspot.com/2007/04/links.html#tools">Web Tools and Programs</a></td> <td bgcolor="#ffffcc"><a href="http://opticalillusions4kids.blogspot.com/2007/04/links.html#misc">Miscellaneous</a></td> </tr></tbody></table>
The below links are to external sites. By following a link to an external site you will be leaving the OI4K website.
<p>When last reviewed, the websites linked from OI4K seemed suitable for you to visit, but that may have changed; if you have any difficulties or concerns with any linked materials, <a href="mailto:illusionsetc@gmail.com">please let us know</a>.
</p><p><span style="color: black; font-style: italic; font-weight: bold;">Kids </span>
We can make sure that you're safe on Optical Illusions 4 Kids (OI4K), but we can't watch out for you on other Web sites. So when you leave OI4K to go to another Web site, check with your parents -- especially if that Web site asks for any personal information about you or your family.
Let your parents know every time someone asks for your personal information online, even when it's a friend. Your parent will tell you when it's OK to give out your personal information. It's better to be safe than sorry, so always ask first!
Most of all, we want you to have fun and stay safe online!</p><hr /> <a name="illusions"> </a><div style="background-color: #a8e0a8;"> <h5><center>Optical Illusion Sites
</center></h5> </div> <div><big><a href="http://www.michaelbach.de/ot/index.html" target="_blank">Optical Illusions & Visual Phenomena</a></big> - an amazing illusion site put together by Michael Bach with explanations and interactive displays.
<big> </big></div><div><big> </big></div><div><big><a href="http://www.anc.ed.ac.uk/%7Eamos/visualillusion.html" target="_blank">Visual Illusion of the Month</a></big>- Amos Storkey's excellent page of unique illusions. He says, "The aim of this page is to provide visual and optical illusions which I think are not the sort that are seen in 101 books etc on illusions."
<big> </big></div><div><big> </big></div><div><big><a href="http://dragon.uml.edu/psych/illusion.html" target="_blank">Illusions Gallery</a></big> - Here is Dr. David Landrigan's gallery of optical illusions. Dr. Landrigan is a Professor at the University of Massachusetts Lowell in their Psychology Department.
<big> </big></div><div><big> </big></div><div><big><a href="http://www.archimedes-lab.org/" target="_blank">Archimedes' Laboratory</a></big> - The visual illusions featured on this page are created by Gianni A. Sarcone and Marie-Jo Waeber. The illusions that the authors offer are, for the greater part, products of their own imagination, sometimes discovered by chance and in other cases they deliberately set out to discover new ways to view existing optical illusions and present them under a new light.
<big> </big></div><div><big> </big></div><div><big><a href="http://www.ritsumei.ac.jp/%7Eakitaoka/index-e.html" target="_blank">Akiyoshi's Illusions</a></big> - This site and the majority of optical illusions presented are the creation of Professor Akiyoshi Kitaoka, Department of Psychology, Ritsumeikan University, Kyoto, Japan.
<big> </big> <br /></div><div> </div><div></div><div><big><a href="http://www.eyetricks.com/illusions.htm" target="_blank">Eyetricks</a></big> - Optical illusions, 3D stereograms and anaglyphs, fractals and brain teasers.
<big> </big></div><div><big> </big></div><div><big><a href="http://www.skytopia.com/project/illusion/illusion.html" target="_blank">Skytopia</a></big> - An intriguing selection of old, new and exclusive optical illusions.
Many pictures are enhanced via the use of 3D and animation.
<big> </big></div><div><big> </big></div><div><big><a href="http://lite.bu.edu/" target="_blank">Project Lite</a></big> is a software, curriculum and materials development project located in the Science and Mathematics Education Center at Boston University.
<big> </big></div><div><big> </big></div><div><big><a href="http://www.grand-illusions.com/" target="_blank">Grand Illusions</a></big> was originally designed as a way of sharing our enthusiasm for various science based phenomena, fun and games, and optical illusions. </div><div> </div><div> <big><a href="http://im-possible.info/english/index.html" target="_blank">Impossible World</a></big> - A site devoted exclusively to the study of impossible figures. After gathering a big collection of impossible figures I decided to create a unique website about impossible figures where as much as possible information about impossible figures and impossible art will be published. <big> <br /></big></div><div><big> </big></div><div><big><a href="https://kids.niehs.nih.gov/games/riddles/illusions/index.htm" target="_blank">NIEHS Optical Illusions</a></big> - A set of optical illusions presented by the National Institute of Environmental Health Sciences.
<big> </big></div><div><big> </big></div><div><big><a href="http://web.mit.edu/persci" target="_blank">Perceptual Science Group</a></big> - the Perceptual Science Group of the MIT Department of Brain and Cognitive Sciences at MIT does research in human visual perception, machine vision, and image processing.
<big> </big></div><div><big> </big></div><div><big><a href="http://www.lockhaven.edu/%7Edsimanek/museum/unwork.htm" target="_blank">Museum of Unworkable Devices</a></big> - This museum is a celebration of fascinating devices that don't work. It houses diverse examples of the perverse genius of inventors who refused to let their thinking be intimidated by the laws of nature, remaining optimistic in the face of repeated failures. </div><div><center> </center><center><a href="http://illusionsetc.blogspot.com/2004/01/friends-of-optical-illusions-etc_16.html#top">Back to top</a></center>
</div> <a name="3d"> </a><div style="background-color: #e8a0a8;"> <h5><center>Blogs</center></h5> </div> <div><big><a href="http://www.dailyillusions.com/" target="_blank"></a></big>
<big><a href="http://puzzlephotos.blogspot.com/">What Is It?</a></big> - Can you guess what the picture is? New photos each week! </div><div><big></big></div><div><big></big></div><div><big></big></div><div><big><a href="http://creditcarddebthelp.blogspot.com/" target="_blank"></a></big>
<center> </center><center><a href="http://illusionsetc.blogspot.com/2004/01/friends-of-optical-illusions-etc_16.html#top">Back to top</a></center>
</div> <a name="science"> </a><div style="background-color: #a8a0e8;"> <h5><center>Science and stuff</center></h5> </div> <div><a href="http://www.howstuffworks.com/"><big>How Stuff Works</big></a> - A very expansive site, giving the low-down on how everything works - the science behind the magic.
<big> </big></div><div><big> </big></div><div><big><span style="font-size: small;"><span style="font-size: medium;"><a href="http://mathforum.org/dr.math/" target="_blank">Ask Dr. Math</a></span>
- A giant archive of math questions for all levels and abilities.
Search for a specific question or browse the online archives. <a href="http://mathworld.wolfram.com/" target="_blank">Here's</a> another great resource too. </span></big><big><br /></big></div><div><big> </big></div><div><a href="http://www.madsci.org/submit.html"><big>Madsci</big></a> - A brilliant site dedicated to answering all your questions about science. This one contains over 25,000 questions, a comprehensive search feature and a forum-style approach to the answers. </div><div> <big> </big></div><div><a href="http://faculty.washington.edu/chudler/neurok.html"><big>Neuroscience for Kids</big></a>- Discover the exciting world of the brain, spinal cord, neurons and the senses. Use the experiments, activities and games to help you learn about the nervous system.
<big> </big></div><div><big> </big></div><div><a href="http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/"><big>Powers of Ten - Universe zoom in</big></a> - An interactive Java applet. "View the Milky Way at 10 million light years from the Earth" ...and then gradually zoom in, passing our solar system, then Earth... a city... tree - all the way down until you reach a tiny atom's nuclei. </div><div><center> </center><center><a href="http://illusionsetc.blogspot.com/2004/01/friends-of-optical-illusions-etc_16.html#top">Back to top</a></center>
</div> <a name="tools"> </a><div style="background-color: #e8e0a8;"> <h5><center>Web Tools and Programs</center></h5> </div> <div> <a href="http://www.wikipedia.org/"><big>Wikipedia</big></a> - A multilingual project to create a complete and accurate open content encyclopedia. An amazing accomplishment, especially considering any person can edit any page at any time.</div><div> </div><div><div><center> </center><center><a href="http://illusionsetc.blogspot.com/2004/01/friends-of-optical-illusions-etc_16.html#top">Back to top</a></center>
</div> </div>Unknownnoreply@blogger.com5