In article ,
"Hagar" wrote:

snip

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.

The atmosphere actually allows us to see slightly more than 180° from
horizon to horizon. Overhead, near the zenith, there's no appreciable
refraction; the effect is strongest near the horizon. This means that
objects at low altitudes are vertically 'squeezed', the lowest, say, ten
degrees of sky containing, say, eleven degrees' worth of the celestial
sphere, as if viewed with a slightly convex mirror or a *reducing* lens.
The disc of a very low Sun or Moon is sometimes perceptibly distorted
into an ellipse or 'football', the axis perpendicular to the horizon
being shortened.

The reddening is caused by the atmosphere's stronger refraction of red
light than of blue (as in a rainbow); incidentally, the same effect
gives the Earth's penumbra its coppery colour when it falls on the Moon
during an eclipse.

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.

That it's an illusion is easy to demonstrate, if you have an open mind:
hold a small coin (or a fingertip) up to the Moon (or, with appropriate
precautions, the Sun) so that it just covers the disc, noting how far
from your eye it needs to be to make the apparent sizes match. Do this
when the Moon (or Sun) is at various altitudes, and compare the results.
Another technique is to roll a piece of paper into a cylinder whose
diameter is such that the disc fills the field of view when it's held to
the eye.

OTOH the mechanism is not perfectly understood, and there are many
theories purporting to explain it, some going back to the mediaeval
Arabs. One that's often put forward suggests that we perceive a low Sun
or Moon to be larger because there are trees, buildings, &c. near the
horizon to compare it to. This is related to what's known as the "Ponzo
illusion". However, the effect can be seen at sea, on the prairie, or
from high-flying aircraft, where such objects are absent from the scene.

Another explanation starts with the observation that we're only
accustomed to seeing very distant objects near the horizon; overhead,
even tall treetops and high-flying birds are only hundreds of metres
away, while mountaintops can be seen from distances in the dozens of
kilometres. In other words, we're conditioned to perceive the dome of
the sky as a shallow bowl instead of a hemisphere. So our brains
interpret an overhead Sun or Moon to be a smallish object at no great
distance, but a rising or setting one to be much further away and
therefore large.

There is also the "oculomotor micropsia" theory, somewhat less
psychological and more physiological, involving the focusing and
accommodation mechanisms in the eye and brain.

Do a Web search for "Moon illusion" to get more info on the phenomenon;
there are plenty of sites that discuss it.

--
Odysseus