Topic started by Sure Thing (@ adsl-64-169-108-155.dsl.lsan03.pacbell.net) on Fri Jul 27 15:21:46 .
All times in EST +10:30 for IST.

Why hasn't there been any firm explanation as to why the Moon looks bigger at the horizon than when it is at the Zenith?

Responses:

• From: shard (@ lan-202-144-125-38.maa.sify.net) on: Sat Jul 28 00:42:48
  
  I thought there already was? Refraction. At the horizon the moon light passes through the earths atmosphere at an angle and light is refracted to a greater extent (more air to go through) than when it is directly overhead. Hold a ball across from a full glass fish tank and look at it head on through the tank...then look at it from an angle.
  
  
• From: Sheker (@ 202.88.233.121) on: Sat Jul 28 04:02:55
  
  Shard,
  I sure would hate to disappoint you, but there is no conventional explanation for the "Moon Illusion". Atmospheric refraction bends light in one way only. Not both ways like a lens. Both the moon and sun subtend the same angle of arc as seen from earth regardless of their position in the sky.
  The "moon illusion" has to do with psychology of human perception and our preconceptions. In fact the moon appears larger at the horizon since it is seen in close juxtaposition to other known large objects. Typically these would be trees, buildings etc. We know that trees and buidings are big. We also know that the moon is much bigger than these. Therefore our brain tells us to perceive the moon as bigger than it seems.
  With your bookland connections you may be able to trace a good book dealing with this topic. If so pl. inform about the title.
  Another optical illusion classic falling in the same category of inexplicable: Our reflection in a mirror is laterally inverted. But why not vertically also, ie. upside down. (our having two eyes has nothing to do with this, as any one-eyed person will tell you!). I believe the jury is still out on this.
  
  Sheker
  
  
• From: Sheker (lunatic) (@ 202.88.233.121) on: Sat Jul 28 06:33:02
  
  All hail Tim Berners Lee. The Net has many sites where the illusion is described in fascinating detail. "Sure Thing", thanks for opening up this new world for me! One site that does the job well is given below. Though, the writer pokes holes in the horizon proximity theory that I proposed above. It's presumably old hat now! www.griffithobs.org/IPSMoonIllus.html
  
  
• From: Sheker (@ 202.88.233.121) on: Sat Jul 28 06:35:10
  
  Sorry. Full URL is given below http://www.griffithobs.org/IPSMoonIllus.html
  Sheker
  
  
• From: shard (@ lan-202-144-125-38.maa.sify.net) on: Sat Jul 28 07:04:29
  
  Thanx Sheker. I'll look it up.
  
  
• From: Sure Thing (@ adsl-64-169-108-230.dsl.lsan03.pacbell.net) on: Mon Jul 30 14:01:20
  
  Sheker,
  
  Yes, BTW, you know what, I believe the illusion will disapper if you look through your legs by bending down. Again, nothing that I have read is conclusive. There have been holes every where on this. That's what baffles me. We have explanations about so many stuff out there, but not this one (closest to earth).
  
  Shard and Shekar, One link I found extremely interesting (perpective building), a must see
  http://www.freemars.org/jeff/2exp100/index.htm
  
  Cheers
  
  
  
• From: Sheker (@ 202.88.232.119) on: Mon Jul 30 23:19:57
  
  Sure Thing,
  That site sure does stretch one's mind!
  I have another "curiosity" for you.
  
  This is my own discovery, heh, heh!!
  
  Indians are only predominantly right handed as is most of the human race, but strong sociocultural taboos prevent the use of the left hand in handling food. Given this, it is surprising all refrigerators sold in India are hinged on the right aide. Thus you open the door with your right hand and taking the food in the right hand is very awkward, forcing you to take it in the left hand. There is technically nothing to prevent the door from being hinged on the left so that the actions are all reversed. Wonder what the fridge companies have to say about this.
  
  
• From: Nagarajan (@ dkf-gw.dkf.de) on: Tue Jul 31 11:52:56
  
  "but strong sociocultural taboos prevent the use of the left hand in handling food"
  
  BTW North Indians eat with both their hands.
  
  
• From: Sheker (@ 202.88.232.106) on: Tue Jul 31 13:12:57
  
  Nagarajan,
  Oops! To cut short a long post I didn't make this distinction. Point taken.
  Sheker
  
  
• From: Sure Thing (@ adsl-64-169-110-68.dsl.lsan03.pacbell.net) on: Tue Jul 31 18:42:54
  
  Sheker,
  
  You are very right about the fridge. I hadn't ever thought of it. For that matter even the lateral inversion and not vertical inversion was very interesting. I'm still baffled.
  
  You may want to take a look at this link.
  Supporters of the theory of Panspermia
  http://www.wired.com/news/print/0,1294,45704,00.html
  
  This is another thing that I hadn't thought off. Up north, I could never find the Sun exactly on top at noon. Also it moved in an arc. Even at noon I saw long shadows. Ofcourse, we know the reason, but it felt so strange when I experienced it.
  
  
• From: Sheker (@ 202.88.233.110) on: Wed Aug 1 09:28:04
  
  Sure Thing,
  Here is a site that maay be worth a glance for the mirror inversion thing. http://bellringers.net/NV1C/Vol1C_286.txt
  Pl. keep me posted on any other good sight on this topic.
  Sheker
  
  
• From: Sure Thing (@ adsl-64-169-110-76.dsl.lsan03.pacbell.net) on: Thu Aug 2 14:07:18
  
  Dear Sheker,
  
  visited the site. Strangely, I couldn't locate any other sites about vertical inversion.
  
  Perhaps you may have visited this intersting site. If you haven't, here it is www.howstuffworks.com
  
  More later......
  
  
• From: Sheker (@ 202.88.232.196) on: Fri Aug 3 01:20:04
  
  Dear Sure Thing,
  Since you're interested such engaging trivia, here's another one. They say that the gopuram of the Brahadheeswara temple in Thanjavur does not cast a shadow on the ground, The shadow, they say, never leaves the base of the gopuram itself. This is of course a physical impossibility; I have visited the temple and did not find anything there that would render basic physics invalid!! But lot of people take this to be gospel truth. Any comments?
  Sheker
  
  
• From: Sheker (@ 202.88.232.196) on: Fri Aug 3 01:48:14
  
  Sure thing,
  Please see also http://www.forumhub.com/indhistory/24682.13.07.33.html
  
  
• From: Sheker (@ 202.88.232.196) on: Fri Aug 3 01:48:38
  
  Sure thing,
  Please see also http://www.forumhub.com/indhistory/24682.13.07.33.html
  
  
• From: Sheker (@ 202.88.232.196) on: Fri Aug 3 01:50:18
  
  Sure thing,
  Re. above the temple shadow business please see also http://www.forumhub.com/indhistory/25682.13.07.33.html
  Sheker
  
  
• From: Sheker (@ 202.88.232.196) on: Fri Aug 3 01:52:33
  
  Sorry. Disregard first two URLs.
  Sheker
  
  
• From: Sure Thing (@ adsl-64-160-22-27.dsl.lsan03.pacbell.net) on: Fri Aug 3 13:54:14
  
  Sheker
  
  Interesting. The fact as it appears is true, as you and many have seen it. Perhaps it has to do with the pyramidal form that the Gopuram was built. Maybe it is one of the properties of the complex features the Eygptians built. I haven't seen the Gopuram, but the more I think about it, the more I am convinced that it has to do with the Pyramidal form. Let me have your thoughts.
  
  

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