{"id":2008,"date":"2026-01-14T12:15:14","date_gmt":"2026-01-14T19:15:14","guid":{"rendered":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/?p=2008"},"modified":"2026-07-21T12:02:48","modified_gmt":"2026-07-21T19:02:48","slug":"poptics-peppers-pyramid","status":"publish","type":"post","link":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/poptics-peppers-pyramid\/","title":{"rendered":"POPtics Pepper&#8217;s Pyramid"},"content":{"rendered":"<p><strong>Overview<\/strong>: Pepper&#8217;s Ghost was popularized in the 1800s and continues to be used today in the entertainment industry, amusement parks, and museums.\u00a0 Aside from being an optical illusion, the technique is also the basis for how teleprompters work.<\/p>\r\n<!-- \/wp:post-content -->\r\n\r\n<!-- wp:paragraph -->\r\n<p>\u200b\u200b<strong>Supplies<\/strong>: 4 transparent trapezoid pieces, tape<\/p>\r\n<!-- \/wp:paragraph -->\r\n\r\n<!-- wp:paragraph -->\r\n<p><strong>Objectives<\/strong>: What is Pepper&#8217;s Ghost? How does light reflect off a surface? How do teleprompters work?<\/p>\r\n<!-- \/wp:paragraph -->\r\n\r\n<!-- wp:separator --><hr class=\"wp-block-separator has-alpha-channel-opacity\" \/><!-- \/wp:separator -->\r\n\r\n<!-- wp:paragraph -->\r\n<p><strong>Setup:<\/strong><\/p>\r\n<!-- \/wp:paragraph -->\r\n\r\n<!-- wp:list -->\r\n<ul><!-- wp:list-item --><\/ul>\r\n<!-- \/wp:list-item -->\r\n\r\n<!-- wp:list -->\r\n<ul><!-- wp:list-item -->\r\n<li>Tape four trapezoids together as shown in the picture below.<\/li>\r\n<!-- \/wp:list-item --><\/ul>\r\n<!-- \/wp:list -->\r\n\r\n<!-- wp:image {\"align\":\"center\",\"id\":305,\"width\":\"474px\",\"height\":\"auto\",\"aspectRatio\":\"1\"} -->\r\n<figure class=\"wp-block-image aligncenter is-resized\"><img fetchpriority=\"high\" decoding=\"async\" width=\"3024\" height=\"3024\" class=\"wp-image-305\" style=\"aspect-ratio: 1 \/ 1; width: 377px; height: 377px;\" src=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/IMG_2051.jpg\" alt=\"\" srcset=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/IMG_2051.jpg 3024w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/IMG_2051-150x150.jpg 150w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/IMG_2051-300x300.jpg 300w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/IMG_2051-768x768.jpg 768w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/IMG_2051-1024x1024.jpg 1024w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/IMG_2051-90x90.jpg 90w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/IMG_2051-75x75.jpg 75w\" sizes=\"(max-width: 3024px) 100vw, 3024px\" \/><\/figure>\r\n<!-- \/wp:image -->\r\n\r\n<!-- wp:list -->\r\n<ul><!-- wp:list-item -->\r\n<li>Add the last piece of tape between the third and fourth trapezoid to form a pyramid.<\/li>\r\n<!-- \/wp:list-item --><\/ul>\r\n<!-- \/wp:list -->\r\n\r\n<!-- wp:paragraph -->\r\n<p><strong>How to run the demo:<\/strong><\/p>\r\n<!-- \/wp:paragraph -->\r\n\r\n<!-- wp:list -->\r\n<ul><!-- wp:list-item -->\r\n<li>Go to this <a href=\"https:\/\/www.youtube.com\/watch?v=CIszi2Kv_lk&amp;feature=youtu.be\" target=\"_blank\" rel=\"noopener noreferrer\">link<\/a>\u00a0or google &#8220;Pepper&#8217;s Pyramid Videos&#8221; to find a video that you like.\u00a0 The best videos will have a bright foreground and a black background.<\/li>\r\n<!-- \/wp:list-item -->\r\n\r\n<!-- wp:list-item -->\r\n<li>Place the center of the pyramid on the center of your screen, turn down the room lights, turn up the brightness on your screen, and play the video.<\/li>\r\n<!-- \/wp:list-item -->\r\n\r\n<!-- wp:list-item -->\r\n<li>When viewed edge-on, you will see a &#8220;floating&#8221; image!<\/li>\r\n<!-- \/wp:list-item --><\/ul>\r\n<!-- \/wp:list -->\r\n\r\n<!-- wp:image {\"align\":\"center\",\"id\":122} -->\r\n<figure class=\"wp-block-image aligncenter\"><img decoding=\"async\" width=\"300\" height=\"169\" class=\"wp-image-122\" src=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/Jojo-300x169.jpg\" alt=\"\" srcset=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/Jojo-300x169.jpg 300w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/Jojo-768x432.jpg 768w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/Jojo-1024x576.jpg 1024w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/Jojo.jpg 2000w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/figure>\r\n<!-- \/wp:image -->\r\n\r\n<!-- wp:separator --><hr class=\"wp-block-separator has-alpha-channel-opacity\" \/><!-- \/wp:separator -->\r\n\r\n<!-- wp:paragraph -->\r\n<p><strong>What&#8217;s happening?<\/strong><\/p>\r\n<!-- \/wp:paragraph -->\r\n\r\n<!-- wp:image {\"align\":\"center\",\"id\":196} -->\r\n<figure class=\"wp-block-image aligncenter\"><img decoding=\"async\" width=\"300\" height=\"149\" class=\"wp-image-196\" src=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/Peppers-Ghost-Diagram-300x149.png\" alt=\"\" srcset=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/Peppers-Ghost-Diagram-300x149.png 300w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/Peppers-Ghost-Diagram-768x381.png 768w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/Peppers-Ghost-Diagram-420x210.png 420w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2018\/04\/Peppers-Ghost-Diagram.png 884w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/figure>\r\n<!-- \/wp:image -->\r\n\r\n<!-- wp:paragraph -->\r\n<p>When light from a bright object (produced by the phone screen) reaches the transparent material, a portion of the light will reflect.\u00a0 For typical plastic, glass, or acrylic, this will be about a 4% reflection.\u00a0 An observer looking at the side of the Pepper&#8217;s Pyramid will then see a virtual image, an object that appears to float inside of the pyramid.<\/p>\r\n<!-- \/wp:paragraph -->\r\n\r\n<!-- wp:paragraph -->\r\n<p>The reflection that you see is from one side of the pyramid.\u00a0 Having four sides allows the illusion to be seen from all angles, and seeing the other edges adds to the illusion that the floating image is contained by the pyramid.<\/p>\r\n<!-- \/wp:paragraph -->\r\n\r\n<!-- wp:paragraph -->\r\n<p><strong>Try this:<\/strong><\/p>\r\n<!-- \/wp:paragraph -->\r\n\r\n<!-- wp:list -->\r\n<ul><!-- wp:list-item -->\r\n<li>Lift up the pyramid off of the screen.\u00a0 Can you still see the image inside?<\/li>\r\n<!-- \/wp:list-item -->\r\n\r\n<!-- wp:list-item -->\r\n<li>Flip the pyramid upside down.\u00a0 What happens to the image?<\/li>\r\n<!-- \/wp:list-item -->\r\n\r\n<!-- wp:list-item -->\r\n<li>If the pyramid will not stand on its own, try adjusting the sides and tape them together again.<\/li>\r\n<!-- \/wp:list-item -->\r\n\r\n<!-- wp:list-item -->\r\n<li>Check out all four sides. Is there a direction where the image is dim or barely visible?\u00a0This means your screen must be linearly polarized!<\/li>\r\n<!-- \/wp:list-item --><\/ul>\r\n<!-- \/wp:list -->\r\n\r\n<!-- wp:paragraph -->\r\n<p><strong>Tips:<\/strong><\/p>\r\n<!-- \/wp:paragraph -->\r\n\r\n<!-- wp:list -->\r\n<ul><!-- wp:list-item -->\r\n<li>Be sure the screen is as bright as possible for the best image, and that the video is playing at fullscreen.<\/li>\r\n<!-- \/wp:list-item -->\r\n\r\n<!-- wp:list-item -->\r\n<li>The pyramid can be folded to be safely carried in your wallet!<\/li>\r\n<!-- \/wp:list-item --><\/ul>\r\n<!-- \/wp:list -->\r\n\r\n<!-- wp:image {\"align\":\"center\",\"id\":609,\"width\":\"259px\",\"height\":\"auto\",\"aspectRatio\":\"0.75\"} -->\r\n<figure class=\"wp-block-image aligncenter is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"2560\" class=\"wp-image-609\" style=\"aspect-ratio: 0.75; width: 259px; height: auto;\" src=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2020\/07\/D8D819FB-F970-4354-B13B-4B1143F9F25B-scaled.jpeg\" alt=\"\" srcset=\"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2020\/07\/D8D819FB-F970-4354-B13B-4B1143F9F25B-scaled.jpeg 1920w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2020\/07\/D8D819FB-F970-4354-B13B-4B1143F9F25B-225x300.jpeg 225w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2020\/07\/D8D819FB-F970-4354-B13B-4B1143F9F25B-768x1024.jpeg 768w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2020\/07\/D8D819FB-F970-4354-B13B-4B1143F9F25B-1152x1536.jpeg 1152w, https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-content\/uploads\/sites\/75\/2020\/07\/D8D819FB-F970-4354-B13B-4B1143F9F25B-1536x2048.jpeg 1536w\" sizes=\"(max-width: 1920px) 100vw, 1920px\" \/><\/figure>\r\n<!-- \/wp:image -->\r\n\r\n<!-- wp:separator --><hr class=\"wp-block-separator has-alpha-channel-opacity\" \/><!-- \/wp:separator -->\r\n\r\n<!-- wp:paragraph -->\r\n<p><em>Note: This is <strong>not<\/strong> a hologram!<\/em><\/p>\r\n<!-- \/wp:paragraph -->\r\n\r\n<!-- wp:paragraph -->\r\n<p>In optics, the word &#8220;hologram&#8221; indicates that there is encoded phase information.\u00a0 An entire scene can be captured by a hologram such that an image changes with different viewpoint, and the creation of a hologram requires a recording medium and two separate laser beams.\u00a0 These Pepper&#8217;s Pyramid projectors use reflection to create a virtual image and are not technically holograms, though they will be commonly recognized as &#8220;holograms&#8221; in popular culture.<\/p><!-- \/wp:paragraph -->","protected":false},"excerpt":{"rendered":"","protected":false},"author":130,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2008","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/posts\/2008","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/users\/130"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/comments?post=2008"}],"version-history":[{"count":6,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/posts\/2008\/revisions"}],"predecessor-version":[{"id":2254,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/posts\/2008\/revisions\/2254"}],"wp:attachment":[{"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/media?parent=2008"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/categories?post=2008"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wp.optics.arizona.edu\/oscoutreach\/wp-json\/wp\/v2\/tags?post=2008"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}