{"id":579,"date":"2013-01-14T09:10:05","date_gmt":"2013-01-14T06:10:05","guid":{"rendered":"http:\/\/dorjegurung.com\/sciblog\/?page_id=579"},"modified":"2026-03-13T19:17:53","modified_gmt":"2026-03-13T19:17:53","slug":"m4-light-entertainment-ii","status":"publish","type":"page","link":"https:\/\/www.dorjegurung.com\/sciblog\/myp4-5-science\/m4-physics\/m4-light-entertainment-ii\/","title":{"rendered":"M4 Light Entertainment II"},"content":{"rendered":"\n<p class=\"has-text-align-center\"><strong><em>Background<\/em><\/strong><\/p>\n\n\n\n<p>Two of the number of processes light undergoes when it interacts with matter is reflection and refraction. Depending on the property of the matter it interacts with, light either bounces back (undergoes reflection) or it passes through the matter but its speed and direction may change&#8211;referred to as refraction.&nbsp;The consequence of these simple processes can be from just unusual to dramatic in real life.<\/p>\n\n\n\n<p class=\"has-text-align-center\"><strong><em>The Discrepant Event: Different Sides of a Rod<\/em><\/strong><\/p>\n\n\n\n<p>For this light entertainment, I took my students to the swimming pool. There, I had them observe the appearance of a pool cleaning rod when dipped inside the pool. Again, instead of having someone film this, I took a series of photos.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img decoding=\"async\" width=\"600\" height=\"307\" src=\"https:\/\/dorjegurung.com\/sciblog\/wp-content\/uploads\/2012\/12\/rod-in-pool-at-angle-side-view-2.jpg\" alt=\"rod in pool at angle- side view 2\" class=\"wp-image-227\" srcset=\"https:\/\/www.dorjegurung.com\/sciblog\/wp-content\/uploads\/2012\/12\/rod-in-pool-at-angle-side-view-2.jpg 600w, https:\/\/www.dorjegurung.com\/sciblog\/wp-content\/uploads\/2012\/12\/rod-in-pool-at-angle-side-view-2-300x154.jpg 300w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/><figcaption class=\"wp-element-caption\">Fig. 1. Side view of the rod inserted at an angle into the pool.<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img decoding=\"async\" width=\"450\" height=\"600\" src=\"https:\/\/dorjegurung.com\/sciblog\/wp-content\/uploads\/2012\/12\/rod-in-pool-at-angle-back-view.jpg\" alt=\"rod in pool at angle- back view\" class=\"wp-image-220\" srcset=\"https:\/\/www.dorjegurung.com\/sciblog\/wp-content\/uploads\/2012\/12\/rod-in-pool-at-angle-back-view.jpg 450w, https:\/\/www.dorjegurung.com\/sciblog\/wp-content\/uploads\/2012\/12\/rod-in-pool-at-angle-back-view-225x300.jpg 225w\" sizes=\"(max-width: 450px) 100vw, 450px\" \/><figcaption class=\"wp-element-caption\">Fig. 2. Back view of the rod inserted into the swimming pool at an angle.<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img decoding=\"async\" width=\"450\" height=\"600\" src=\"https:\/\/dorjegurung.com\/sciblog\/wp-content\/uploads\/2012\/12\/rod-in-the-pool-at-angle-front-view.jpg\" alt=\"rod in the pool at angle - front view\" class=\"wp-image-222\" srcset=\"https:\/\/www.dorjegurung.com\/sciblog\/wp-content\/uploads\/2012\/12\/rod-in-the-pool-at-angle-front-view.jpg 450w, https:\/\/www.dorjegurung.com\/sciblog\/wp-content\/uploads\/2012\/12\/rod-in-the-pool-at-angle-front-view-225x300.jpg 225w\" sizes=\"(max-width: 450px) 100vw, 450px\" \/><figcaption class=\"wp-element-caption\">Fig. 3. Front view of the rod inserted at an angle into the pool.<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img decoding=\"async\" width=\"450\" height=\"600\" src=\"https:\/\/dorjegurung.com\/sciblog\/wp-content\/uploads\/2012\/12\/rod-in-pool-vertical.jpg\" alt=\"rod inserted vertically in the pool\" class=\"wp-image-221\" srcset=\"https:\/\/www.dorjegurung.com\/sciblog\/wp-content\/uploads\/2012\/12\/rod-in-pool-vertical.jpg 450w, https:\/\/www.dorjegurung.com\/sciblog\/wp-content\/uploads\/2012\/12\/rod-in-pool-vertical-225x300.jpg 225w\" sizes=\"(max-width: 450px) 100vw, 450px\" \/><figcaption class=\"wp-element-caption\">Fig. 4. Side view of the rod this time inserted straight down into the pool.<\/figcaption><\/figure>\n\n\n\n<p>And the question is: Why does the swimming-pool cleaning rod appear bent as it does in figures 1 and 2 but not in figures 3 and 4?<\/p>\n\n\n\n<p>Extension: When at a swimming pool, standing at one end of the pool looking across about to jump or dive in, I am sure you have noticed how the far end appears to be shallower. The pool appears to be getting steadily shallower as your gaze travels from the near end to the far end. Why?<\/p>\n\n\n\n<p>Concepts involved:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>image, normal, rare medium, dense medium,&nbsp;reflection, refraction, angle of incidence, angle of refraction, speed of light, line of sight (Additional advanced concepts: refractive index)<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Background Two of the number of processes light undergoes when it interacts with matter is reflection and refraction. Depending on the property of the matter it interacts with, light either bounces back (undergoes reflection) or it passes through the matter but its speed and direction may change&#8211;referred to as refraction.&nbsp;The consequence of these simple processes [&hellip;]<\/p>\n","protected":false},"author":6,"featured_media":2578,"parent":737,"menu_order":0,"comment_status":"open","ping_status":"closed","template":"","meta":{"jetpack_post_was_ever_published":false,"footnotes":""},"class_list":["post-579","page","type-page","status-publish","has-post-thumbnail","hentry"],"blocksy_meta":[],"jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/P2Y7Kk-9l","_links":{"self":[{"href":"https:\/\/www.dorjegurung.com\/sciblog\/wp-json\/wp\/v2\/pages\/579","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.dorjegurung.com\/sciblog\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.dorjegurung.com\/sciblog\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.dorjegurung.com\/sciblog\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.dorjegurung.com\/sciblog\/wp-json\/wp\/v2\/comments?post=579"}],"version-history":[{"count":2,"href":"https:\/\/www.dorjegurung.com\/sciblog\/wp-json\/wp\/v2\/pages\/579\/revisions"}],"predecessor-version":[{"id":4231,"href":"https:\/\/www.dorjegurung.com\/sciblog\/wp-json\/wp\/v2\/pages\/579\/revisions\/4231"}],"up":[{"embeddable":true,"href":"https:\/\/www.dorjegurung.com\/sciblog\/wp-json\/wp\/v2\/pages\/737"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.dorjegurung.com\/sciblog\/wp-json\/wp\/v2\/media\/2578"}],"wp:attachment":[{"href":"https:\/\/www.dorjegurung.com\/sciblog\/wp-json\/wp\/v2\/media?parent=579"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}