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P3D the "moon bigger near the horizon" illusion
- From: "Jeff Jessee" <jeffjessee@xxxxxxxxxxxxx>
- Subject: P3D the "moon bigger near the horizon" illusion
- Date: Mon, 17 Jan 2000 17:35:26 -0700
I have thought about the moon illusion for many years, and
have never seen a satisfactory explanation of it. So here's
what I have come up with.
Like many illusions, the brain is trying to interpret what
it sees in the most consistent, logical way, given its past
experiences. Consider objects that we see moving across the
sky. Stars have no apparent size, so we can ignore them.
Everything else that we commonly see in the sky, other than
the sun and the moon, (planes, birds, etc.) are largest when
they are overhead, and get progressively smaller as they
move toward the horizon, approaching zero as they approach
the horizon,because they are actually getting further away
from us. All except the sun and moon. So when the moon does
not get smaller as it nears the horizon, as its supposed to,
the brain interprets that it must be getting bigger, because
its "experience" is that as objects get closer to the
horizon, they are getting further away from us, and
therefore, smaller. Seems to me the only assumption I have
to make for my explanation to be reasonable, is that the
part of the brain that knows the moon really isn't getting
further away, is not in direct communication with the part
of the brain that is interpreting what we see. I'll leave it
to someone who knows more about how the brain works than I
to tell me if that's a reasonable assumption.
Thanks for your time, and pardon the non-3D digression
Does this make sense to anyone?
Jeff Jessee
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