The moon

[R1chie]

Has anyone noticed how big the moon has been lately. I was riding today and the sun went down, the moon was huge when it was rising. I rushed home to take a picture of it but as it rises it gets smaller and it was pretty small by the time I got home though bigger than usual. I still took a picture of it.

http://www.mxphotos.net/moon/moon.jpg

[King Nothing]

Sweet pic.

[Bueller]

It's the atmosphere, when it is at the horizon it magnifies it.

[King Nothing]

THE SKY IS FALLING!!!!!!!!!!!!

[R1chie]

It's the atmosphere, when it is at the horizon it magnifies it.

I was aware but do you know why looks bigger now than say, 3 months ago at the horizon or at 12 oclock in the sky? I would assume the cooler temps have something to do with it, I don't think the moon changes orbit enough to make a size difference.

[pilot]

It's a Bush conspiracy. Just kidding, just kidding.

Last night, riding down from the Buck Snort (Pine) the Moon looked pretty good rising over the hills to the east.

[Bueller]

That's as much as I know, my mind is like a full trashcan, if I learned more about it, something else would have to go, and that would probably be my name or addres :dunno:

[pilot]

That's as much as I know, my mind is like a full trashcan, if I learned more about it, something else would have to go, and that would probably be my name or addres :dunno:

http://www.seminolecountyfl.gov/envsrvs/solidwaste/images/captlitter.gif

[dirkterrell]

It's the atmosphere, when it is at the horizon it magnifies it.

Actually, it isn't. Atmospheric refraction actually squashes the Moon top to bottom slightly. The Moon's appearing large at the horizon is an optical illusion, and thus a psychological phenomenon rather than a physical phenomenon. An easy way to test this is to use the tip of your thumb at arm's length to just cover the Moon when low and high in the sky. You will see that the Moon stays about the same size. (If you carefully measured it, you would see that it is a little smaller on the horizon because it is farther away than when it is overhead.) Some think that this is an example of something called the Ponzo Illusion. Wikipedia has a couple of relevant articles:

http://en.wikipedia.org/wiki/Moon_illusion

http://en.wikipedia.org/wiki/Ponzo_illusion

Dirk

[Bueller]

Now you did it! I gotta find my drivers license quick.

[pilot]

Actually, it isn't. Atmospheric refraction actually squashes the Moon top to bottom slightly. The Moon's appearing large at the horizon is an optical illusion, and thus a psychological phenomenon rather than a physical phenomenon. An easy way to test this is to use the tip of your thumb at arm's length to just cover the Moon when low and high in the sky. You will see that the Moon stays the same size. Some think that this is an example of something called the Ponzo Illusion. Wikipedia has a couple of relevant articles:

http://en.wikipedia.org/wiki/Moon_illusion

http://en.wikipedia.org/wiki/Ponzo_illusion

DirkBull Hockey! The moon is made of green cheese and Jim Carey is yanking it down to earth!

http://www.geocities.com/rmm413/GleasonCartoonMoon.gif









http://www.moviepoopshoot.com/elsewhere/images/2003/may7/bruce1.jpg

[dirkterrell]

Now you did it! I gotta find my drivers license quick.

Your brain is probably full of much more useful things than mine filled with useless shit like the Ponzo illusion. http://www.boulder.swri.edu/%7Eterrell/images/goofy.gif

Dirk

[Drift]

...over the hills to the east.

There are hills to the East? I have not lived here that long but I have noticed a few small ones to the West... :)

[pilot]

There are hills to the East? I have not lived here that long but I have noticed a few small ones to the West... :)That depends on which way she is lying down...

http://www.orbit.zkm.de/files/orbit/LinkoftheMoon_MarikoMori.jpg

[64BonnieLass]

Now you did it! I gotta find my drivers license quick.

:pointlaugh:

Dirk FTW.

Nice pic Richie. It has been very nice to see all week.

[puckstr]

No not again.
http://imagecache2.allposters.com/images/151/PP0652.jpg

[puckstr]

Bull Hockey! The moon is made of green cheese and Jim Carey is yanking it down to earth!



Ahhhh Bullsnot

The moon is made of barbequed spare ribs.
http://www.robotsandwrestlers.com/wp-content/uploads/caray3.jpg

[R1chie]

I guess I heard the same thing as bueller. But after reading wiki, it is amazing that our perception of the moon changing is just that, a perception. So it wouldn't have mattered if I got home the moon would have photographed the same size. I did go out and there are some other theories as to why it looks bigger and some reject Ponzo explaination as to why we perceive the size difference but never the less, it does not change size. Good to know.

Actually, it isn't. Atmospheric refraction actually squashes the Moon top to bottom slightly. The Moon's appearing large at the horizon is an optical illusion, and thus a psychological phenomenon rather than a physical phenomenon. An easy way to test this is to use the tip of your thumb at arm's length to just cover the Moon when low and high in the sky. You will see that the Moon stays about the same size. (If you carefully measured it, you would see that it is a little smaller on the horizon because it is farther away than when it is overhead.) Some think that this is an example of something called the Ponzo Illusion. Wikipedia has a couple of relevant articles:

http://en.wikipedia.org/wiki/Moon_illusion

http://en.wikipedia.org/wiki/Ponzo_illusion

Dirk

[(( LO LO ))]

Wow, the moon did look huge the other night when it was rising here. Very strange...

[Mental]

Dumb question, and I'd rather stimulate conversation than look it up, but aren't most planetary orbits elongated circles, so wouldn't there be pionts where the moon would be closer than others?

[gsxrscott]

Yes, hence high tide and low tide. (moon's pull) mabey?:crazy:

[puckstr]

Dumb question, and I'd rather stimulate conversation than look it up, but aren't most planetary orbits elongated circles, so wouldn't there be pionts where the moon would be closer than others?

Dirk...
This has your name all over it

[Joecycle]

My brain is starting to hurt :crazy:.

... and there's no such thing as high tide and low tide......the beach moves !

[pilot]

I'm no expert, but the Moon's gravitational pull exerts itself upon the seas, you, me and the tectonic plates. As the Sun and the moon line up to the same side of the Earth the gravitational pull is increased and the highest tides are seen (that would be during the "new moon" phase). During a full Moon, like now tides are also high, as the Sun and the Moon are on opposite sides of the Earth. This causes the seas to be in an egg-shape on the surface of the Earth. Lowest, or "neap" tides are when we have a 1/4 or 3/4 Moon. Even though the Sun is a heck of a lot bigger than the moon, due to its distance, the effect it has on the Earth is less than 50% that of the Moon.

So, when your GF asks you if she looks "big" in those jeans, check the phase of the Moon.

The math is fun, too. But, I'll leave that to Cycle Monkey as he gets hard on that kind of stuff.

[salsashark]

Just like the Koala... the moon's a bitch!

[King Nothing]

I punch bees in the face.

[PhL0aTeR]

Just like the Koala... the moon's a bitch!

the moon be weak..... but yeah that moon is huge.... it almost takes up my whole screen!

[dirkterrell]

Dumb question, and I'd rather stimulate conversation than look it up, but aren't most planetary orbits elongated circles, so wouldn't there be pionts where the moon would be closer than others?

Yes, closed orbits are elliptical (the circle is just a special case of the ellipse) and the eccentricity (e) tells you how elliptical it is. e=0 is a circle and e approaching 1 is a long, cigar shaped ellipse. I can go into more detail but I don't want Bueller's head to explode. :) So, yes, there are times when the Moon is farther away (apogee) and closer (perigee) and that will obviously change its apparent size. But the Moon's eccentricity is only about 0.05 so it is a small effect.

Dirk

[pilot]

Apogee, perigee. A fresh way to describe the turn of a motorcycle through a corner.

[puckstr]

Apogee, perigee. A fresh way to describe the turn of a motorcycle through a corner.

also throw in Vector, Velocity, and Vulva

[dirkterrell]

I'm no expert, but the Moon's gravitational pull exerts itself upon the seas, you, me and the tectonic plates. As the Sun and the moon line up to the same side of the Earth the gravitational pull is increased and the highest tides are seen (that would be during the "new moon" phase). During a full Moon, like now tides are also high, as the Sun and the Moon are on opposite sides of the Earth. This causes the seas to be in an egg-shape on the surface of the Earth. Lowest, or "neap" tides are when we have a 1/4 or 3/4 Moon. Even though the Sun is a heck of a lot bigger than the moon, due to its distance, the effect it has on the Earth is less than 50% that of the Moon.

Correct. The tidal forces arise from the fact that one side of a planet/moon is closer to the other planet/moon and thus experiences a larger gravitational force (because gravity declines with increasing distance from a body, proportional to the square of the distance to be exact. Twice as far from the Earth's center, you would weigh half as much. Hmmm, that gives me an idea for the next big diet book...)

When the Sun and the Moon are in a line with the Earth (new or full Moon), the extra help from the Sun gives larger tides. When the Earth-Moon-Sun make a right angle (quarter phases), the Sun and the Moon are pulling at right angles to each other rather than with each other, so the tides aren't quite as high. If you have the new/full phases of the Moon occur at perigee, then you'll get even bigger tides because the Moon is a little closer than normal.

Dirk

[R1chie]

Dang, you guys must be bored.