![]() |
|
|
Thread Tools | Display Modes |
#14
|
|||
|
|||
![]() "Hagar" wrote in message ... "Roger Hamlett" wrote in message ... "Hagar" wrote in message ... "Odysseus" wrote in message news ![]() "Hagar" wrote: [...] riding to work on Friday morning I saw the Moon setting in the west, about 6:30am and it was quite a sight; it appeared three times its normal size and had a dark-reddish tint, almost as one would expect Mars to appear, at close range. I am sure the amplification effect was caused by atmospheric lensing. If by "amplification" you mean its great apparent size, that's not due to the atmosphere, but to a well-known perceptual illusion. Images of an object near the horizon actually get compressed by atmospheric refraction, quite the opposite of what our visual sense tells us. -- Odysseus OK, one more time: The ****ing Moon looked 2.5 times its normal size. It was also bathed in a burnt orange like color. No, it is not an illusion, because I have watched the Sun set in the Pacific ocean, displaying identical traits. The additional "ether" one has to look through when eyeing a visual path parallel to the Earth's surface must act like a lens, making the Sun and the Moon appear larger, as they approach the horizon. Actually, the optical effects, make it look slightly smaller!.... However the way our 'brains' work, make it look a lot larger. The only way to really get an idea of the size of the Moon at any time, when just looking at it, is to 'override' the effect, hold your arm out, and compare the actual size with (say) the size of the end of your thumb at arms length. This gives you a reasonably 'constant' reference, and you may well be suprised at what you find!... So, you can either explain in detail the mystery of your "well-known perceptual illusion", or shut up, because it sounds like gibberish to me. The illusion, is because there is a system in our visual processing, which stops people/houses etc., from looking as small as they really are, when a long way away. Effectively the visual processing in your head, says 'this is a long way away, make it look bigger'. It tends only to come into force, when something is low enough in the sky, that your brain starts thinking 'this is near the horizon'. Best Wishes So, all the pictures of Pacific sunsets, where there is nothing bat water, showing a larger than normal disk of good old Sol, are taken by cameras whose film has been fooled by an optical illusion ?? No. Just a telephoto lens. On a photgraph, you can make the scale anything you want.... Best Wishes |
Thread Tools | |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
two classes of readily noticeable common, ubiquitous, uniform bright blue sources in deep background (Murray mesh) of HUDF, dwarf galaxy luminous bare clumps, hyper novae?: 2005.04.01 BG and DM Elmegreen: Malcolm Fairbairn: Murray 2005.11.11 | Rich Murray | Amateur Astronomy | 2 | November 12th 05 05:33 AM |
two classes of readily noticeable common, ubiquitous, uniform bright blue sources in deep background (Murray mesh) of HUDF, dwarf galaxy luminous bare clumps, hyper novae?: 2005.04.01 BG and DM Elmegreen: Malcolm Fairbairn: Murray 2005.11.11 | Rich Murray | Astronomy Misc | 0 | November 12th 05 04:00 AM |
**A FINE SEPTEMBER NIGHT (Sept. 9th) | David Knisely | Amateur Astronomy | 6 | September 26th 04 08:30 AM |
Link to cancer and bright night lighting??!!! | francis marion | Amateur Astronomy | 1 | September 10th 04 06:36 AM |
Mars Looms Big & Bright as It Nears Record-Breaking Close Approach | Ron Baalke | Misc | 4 | August 10th 03 08:15 AM |