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Verlan J. Kliewer
2002-Oct-23, 01:20 PM
When you look at the moon, on the horizon, when it is full, the moon appears to be much closer and bigger than what it does when it appears directly overhead in the sky.

Why is this?

Some scientists have taken the position that the moon actually is not closer, and it has not changed its size, but rather this is an optical illusion, caused by comparing the size of the moon with other objects on the horizon.

Every competent scientist knows the truth behind this, and why it happens.

So I have fabricated the following:

When the moon is full, then you can see more of the moon. Then obviously, a greater area of the moon’s surface is exposed to the gravitational attraction of the earth. This causes the moon to draw closer to the earth when it is full. Thus, when the moon is full on the horizon, it appears to be closer and bigger because the gravitational attraction is greater, and, indeed, the moon is closer to the earth.

How is this for bad astronomy? Do you have room for humor on this web site?

I am almost ashamed to put such ideas on this web site, because I do not believe it myself.

The action of photons and solar activity hitting a full moon could drive the moon further from the earth, but when the moon is full (if you were on the moon, it would appear as if you had a new earth), photons and solar activity would hit the earth driving it closer to the moon.

When the moon is new (if you were on the moon, it would appear as if you had a full earth), the action of photons and solar activity hitting the moon would drive it closer to the earth, and the action of the photons and solar activity hitting the earth would drive it away from the moon.

How significant is this? Probably very insignificant.

The moon does have a ridiculously thin atmosphere, which increases and decreases according to solar activity.

This topic was triggered by a statement in made in a serious topic about relativity:

HUb' Bad Master stated, "so the question may as well be Velocity (or in my terms) how quickly {SLOWLY} IS THE mOON RECEEDING FROM EARTH"

GrapesOfWrath
2002-Oct-23, 02:07 PM
On 2002-10-23 09:20, Verlan J. Kliewer wrote:
When the moon is full, then you can see more of the moon. Then obviously, a greater area of the moon’s surface is exposed to the gravitational attraction of the earth. This causes the moon to draw closer to the earth when it is full. Thus, when the moon is full on the horizon, it appears to be closer and bigger because the gravitational attraction is greater, and, indeed, the moon is closer to the earth.
Yahbut, the illusion is still occurs when the moon is full not on the horizon--it still looks bigger on the horizon.

The BA discusses it in his book, and online (http://www.badastronomy.com/bad/misc/moonbig.html).

How is this for bad astronomy? Do you have room for humor on this web site?
We welcome all attempts at humor, on this web site.

<font size=-1>[ This Message was edited by: GrapesOfWrath on 2002-10-23 10:08 ]</font>