[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-608102-105":59,"doc-detail-608102-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","the-moon-illusion-explained-introduction-and-summary","The Moon Illusion Explained - Introduction and Summary","","Explores why the full Moon near the horizon typically appears larger than when higher in the sky. Reviews a relatively new theory proposing that what most people report as “larger” begins as an angular subtense difference, not an optical magnification. Distinguishes angular, linear, and distance components of the illusion, addresses the subjectivity emphasized by earlier research, and reviews the conventional apparent-distance approach alongside the size-distance paradox and misleading popular diagrams.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/the-moon-illusion-explained-introduction-and-summary/608102/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/the-moon-illusion-explained-introduction-and-summary/608102.png","ImageObject",300,407,{"name":92,"@type":93},"Stanford","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-22","2026-10-17",true,{"@type":102,"interactionType":103,"userInteractionCount":14},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"What is the central observation of the moon illusion described here?","Question",{"text":112,"@type":113},"The full Moon near the horizon usually appears larger than when it is higher up toward the zenith. The article emphasizes that this is a perceived difference rather than an optical magnification.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"Why does the article distinguish angular, linear, and distance illusions?",{"text":117,"@type":113},"It argues that for many observers multiple “size” interpretations occur together: angular size, perceived linear diameter, and an additional impression about distance. These are reported as “larger and closer/farther,” but the closer judgment follows from the angular-size report rather than from a true distance cue.",{"name":119,"@type":110,"acceptedAnswer":120},"How does the conventional apparent-distance theory fail according to the article?",{"text":121,"@type":113},"The conventional theory requires that observers report the horizon Moon as both larger and farther away, yet most people instead report it as larger and about as far away or larger and closer. This mismatch is described as the “size-distance paradox.”","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},608102,1792644409,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":14,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":56,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":143,"read_time":144},2336477552062,"https://ap-avatar.wpscdn.com/davatar_994ba38a5ba835b3df7d355c54d3ed8d","The Moon Illusion Explained  \nFinally! Why the Moon Looks Big at the Horizon and Smaller When Higher Up.  \nDon McCready Professor Emeritus,  \nPsychology Department  \nUniversity of Wisconsin-Whitewater  \nWhitewater, WI 53190  \nEmail [to: mccreadd at uww.edu](to: mccreadd at uww.edu)  \nIntroduction and Summary [Revised 12/07/02]  \nFor many centuries, scientists have been puzzled by the illusion that the full moon at the horizon usually looks larger than it does later, at higher elevations toward the zenith of the sky. Many explanations (theories) have been offered. But, it is fair to say that the two dozen (or so) scientists most familiar with current research on the illusion have not yet accepted any one theory. The jury is still out.  \nThe theory reviewed in this article is relatively quite new (McCready, 1983, 1985, 1986). It begins with the basic assumption that, when most people say \"the moon looks larger,\" they are referring primarily to the moon's angular subtense (McCready, 1965).  \nThat is, the horizon moon looks a larger angular size than the zenith moon.  \nThat experience is imitated if you look at the circles in the figure at the right, because the lower circle subtends a larger angle at your eye than the upper circle does.  \nAngular Size Illusion.  \nFor the moon, that appearance is known as the moon illusion, because the angle the moon's diameter subtends at your eye measures about 1⁄2 degree of arc no matter where the moon is in the sky. That is, there is  \nno physical (optical) reason why the horizon moon should look larger than the zenith moon: For instance, it has been known for centuries that the horizon moon is not\"magnified' by the earth's atmosphere. Indeed, the 11th century Arabian astronomer, Ibn al-Haytham,[Alhazen] is credited with being the first scientist to point out that the illusion is entirely a subjective (or \"psychological\") illusion (see Ross & Plug, 2002).  \nAlso a Linear Size Illusion  \nGiven that for most people the moon illusion begins as an angular size illusion, for many of them, the horizon moon's physical (metric) diameter, its linear size in meters, also looks larger than the zenith moon's linear size. That is, for most observers two quite different \"size\" illusions occur at the same time.  \nAlso a Distance Illusion  \nThere also usually is a distance illusion: Most people say the distance from them to the horizon moon usually looks less than the distance to the zenith moon. It is very  \nimportant to keep in mind that the report most often given is that the horizon moon\"looks larger and closer\" than the zenith moon. The reason it \"looks closer\" is because its angular size \"looks larger. \" Of course, \"looks larger\" often refers, as well, to the linear size comparison, but an apparently larger linear size is not a perceptual cue to a shorter distance.  \nThe same illusion also occurs for the sun and for the constellations as they appear to move between horizon and zenith positions. The term 'moon illusion' commonly is used for all such examples, however.  \nFor more than 100 years, vision scientists (a specialty within psychology) have been conducting experiments on the moon illusion. It has been discussed in perception textbooks and even in introductory psychology textbooks for more than 60 years. Those texts typically have offered one or two explanations (theories). A few texts also have pointed out, however, that these conventional theories simply do not explain the moon illusion.  \nTo see why that is, consider the most widely published explanation.  \nThe Conventional Theory  \nToday the best-known explanations are versions of the apparent distance theory.  \nThat theory implicitly assumes that the horizon moon and zenith moon look the same angular size (in degrees), as imitated for us by the two equal circles in the diagram at the left. So, the only \"size\" the theory refers to is the moon's metric size, its physical diameter in meters, here called its linear size. (Thus also its volume in ","cbCaivPhH2ImFqlw","https://ap.wps.com/l/cbCaivPhH2ImFqlw","pdf",936573,"English","# Introduction and Summary\n## Angular Size Illusion\n## Also a Linear Size Illusion\n## Also a Distance Illusion\n## The Conventional Theory\n## Misleading Illustrations","[{\"question\":\"What is the central observation of the moon illusion described here?\",\"answer\":\"The full Moon near the horizon usually appears larger than when it is higher up toward the zenith. The article emphasizes that this is a perceived difference rather than an optical magnification.\"},{\"question\":\"Why does the article distinguish angular, linear, and distance illusions?\",\"answer\":\"It argues that for many observers multiple “size” interpretations occur together: angular size, perceived linear diameter, and an additional impression about distance. These are reported as “larger and closer/farther,” but the closer judgment follows from the angular-size report rather than from a true distance cue.\"},{\"question\":\"How does the conventional apparent-distance theory fail according to the article?\",\"answer\":\"The conventional theory requires that observers report the horizon Moon as both larger and farther away, yet most people instead report it as larger and about as far away or larger and closer. This mismatch is described as the “size-distance paradox.”\"}]","The Moon Illusion Explained - Introduction and Summary | PDF",1792216153,48]