MOON so low in the sky .. felt like I could touch it ...

"BllFs6" wrote in message
...
wrote in message
news:0UCWb.39247$QJ3.10257@fed1read04...
is the moon closer to earth (hence larger in appearance) when it is on
the
horizon?

Sorry if this is a stupid question.

M



No, its not noticably closer or further away.....

HOWEVER....that the moon or sun (or even small constellations) somehow
SEEM to
APPEAR larger when they are on the horizon is a well know OPTICAL
illusion...

anybody here up on the reason for said illusion?

take care

Blll

All the theories I have seen about this optical illusion say the same thing,
that it is only because it looks bigger when there are objects close on the
horizon to act as a reference. Once it gets up on it's own so to speak it
looks like a comparatively small object surrounded by nothing. The old way
of demonstrating this was to sit in a room where the moon could be seen just
after rising and getting someone else to stick two bits of tape on the
window, one above and one below the moon and just touching. A few hours
later do it again, sitting in the same position, then measure the gaps
between the two pairs of tape. It will then show that the actual size has
not in fact changed, even though you may find it hard to believe.

MikeB

Hi Starford It could be we are seeing the moon coming to us over trees
or over hills and these objects seen at a distance are made smaller with
distance(perspective) so the brain can judge distance. A moon over head
would be the size of a Quarter held at arms length,and ditto close to
the Earth's horizon. It is perspective that is giving you an illusion of
the moon being bigger close to the horizon. I take pictures proving
this,and they are fun to see. Bert

On Thu, 12 Feb 2004 08:47:23 -0800, "Starlord"
wrote:

No, it's just because your seeing the moon threw more of the Earths blanket of
air.

I'm afraid that's incorrect.

The moon looks larger when nearer to a horizon due to an optical
illusion. There are trees, houses etc with which the size of the moon
is unconsciously compared by the eye.

Remove the horizon and its objects and the moon size will appear
quite normal in size.

From Bert:

It is perspective that is giving you an
illusion of the moon being bigger close to the horizon. I take
pictures proving
this,and they are fun to see.

I think that's 'Darla' mooning us. oc =A0

Hi oc Yes Darla can do it. She has unlimited energy at her finger
tips,and can use that energy to move the moon closer to Earth at moon
rises,and moon sets,. Bert

Merv wrote:

The moon looks larger when nearer to a horizon due to an optical
illusion. There are trees, houses etc with which the size of the moon
is unconsciously compared by the eye.

Remove the horizon and its objects and the moon size will appear
quite normal in size.

That explanation, although often given, is disputed: most telling IMO
is that the effect occurs even at sea where there's nothing to refer
to on the horizon. It seems that our depth-perception is not easily
dissuaded from considering objects seen overhead to be much closer
than than when they're near the horizon. Try a search for "Ponzo
illusion" -- I found this site right away:

http://unmuseum.mus.pa.us/exmoon.htm.

--
Odysseus

Odysseus wrote in
:

Merv wrote:

The moon looks larger when nearer to a horizon due to an optical
illusion. There are trees, houses etc with which the size of the moon
is unconsciously compared by the eye.

Remove the horizon and its objects and the moon size will appear quite
normal in size.

That explanation, although often given, is disputed: most telling IMO
is that the effect occurs even at sea where there's nothing to refer
to on the horizon. It seems that our depth-perception is not easily
dissuaded from considering objects seen overhead to be much closer
than than when they're near the horizon. Try a search for "Ponzo
illusion" -- I found this site right away:

http://unmuseum.mus.pa.us/exmoon.htm.


It is currious that while the moon looks bigger near the horizon it is
actually a greater distance from the observer than when culmniating and
looking smaller - when it is actully closer!

The illusion also occurs for constellations near the horizon. For example,
Orion to me always looks nearly twice the size rising or setting than when
culminating (mid latitudes). And this is over land or sea horizons.
Curiously, in the all-sky monthly maps like those in Sky&Tel and Astronomy,
constellations are accidently enlarged near the horizon due to the
stereographic projection used to make them. This by coincidence nicely
emulates the constellation enlargement near the horizon in the real sky.

Martin Lewicki