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Astronomy question
Posted: 31 December 2007 06:30 AM   [ Ignore ]   [ # 31 ]
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Pfuuuiii….

In a forum that promotes science as the sure source of knowledge, some people seem not to understand some very basic facts… Mixing up dark and bright sides with front and back sides, movement around its own axis and around something else… tongue rolleye . If these animations do not help, what does?

Here I have a quiz question for Mriana and George. In what season of the year does the full moon reaches its highest point?

GdB

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Posted: 31 December 2007 08:02 AM   [ Ignore ]   [ # 32 ]
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GdB - 31 December 2007 06:30 AM

Here I have a quiz question for Mriana and George. In what season of the year does the full moon reaches its highest point?

The day of the birth of our Lord, Jesus Christ.

GdB - 31 December 2007 06:30 AM

In a forum that promotes science as the sure source of knowledge, some people seem not to understand some very basic facts…

Maybe that’s why those people come to this forum: to learn!

A quiz for you: why does the moon spin about its axis?

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Posted: 31 December 2007 08:16 AM   [ Ignore ]   [ # 33 ]
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George - 31 December 2007 08:02 AM
GdB - 31 December 2007 06:30 AM

In what season of the year does the full moon reaches its highest point?

The day of the birth of our Lord, Jesus Christ.

A quibble: Jesus was probably born in the summertime, if we accept Middle-east type weather, and take literally the vague clue that at the time shepherds were watching flocks ‘by night’.

It also happens that the winter solstice date was known to be more symbolic than real even by the orthodox of the early church.

Kirk

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Posted: 31 December 2007 08:24 AM   [ Ignore ]   [ # 34 ]
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No, Jesus was born in the winter. I clearly remember, as a kid, seeing pictures of the nativity in Bethlehem covered in snow.

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Posted: 31 December 2007 08:52 AM   [ Ignore ]   [ # 35 ]
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George.

Heh. How old are you? Maybe you’re a potential eye-witness. >:)

Kirk

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Posted: 31 December 2007 09:03 AM   [ Ignore ]   [ # 36 ]
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A quibble: Jesus may never have been born at all. But what does this have to do with the phases of the moon?

GdB-Play nice and try not to be snotty, ok?

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Posted: 31 December 2007 09:05 AM   [ Ignore ]   [ # 37 ]
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mckenzievmd - 30 December 2007 05:22 PM

Mriana,

HERE is a site that has diagrams and a protocol for an experiment like George’s you can do at home.

Here is a VIDEO SIMULATION that might help.


Another VIDEO SIMULATION The “view from the sun” is the best way to look at this one for our purpose.

These are excellent resources, thank you Brennen.  In a world where we get our weather forecasts explained in terms of the sun rising & setting, it is no wonder celestial misunderstandings are so common.  Egotistically speaking the universe still revolves around the individual.  hmmm

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Posted: 31 December 2007 09:25 AM   [ Ignore ]   [ # 38 ]
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Speaking of phases of the Moon, here is our goddess Selene caught at her nearest and farthest approach. This was one of the many pieces of evidence Ptolemy used to argue moving from perfectly concentric orbits to ‘eccentric’ orbits.

http://antwrp.gsfc.nasa.gov/apod/ap991222.html

Ancient astronomers already noticed that Venus never wanders far from the Sun. That is, Venus never is in opposition to the Sun, but rises and sets not much before or after the Sun. Galileo’s telescopic observations of the phases of Venus (you can’t see them with the naked eye) ‘prove’ that Venus does not go around the Earth, but goes around the Sun.

Test question: Give the proof, using that fact about Venus not wandering far from the Sun, and the ‘gif’ below:

http://antwrp.gsfc.nasa.gov/apod/ap060110.html

I’ve taught a Scientific Revolution class, and found some of this stuff while researching for it. If you’re not a natural engineer, it’s tough to move bodies in your imagination.

Kirk

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Posted: 31 December 2007 09:37 AM   [ Ignore ]   [ # 39 ]
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psikeyhackr - 30 December 2007 10:04 PM
Mriana - 30 December 2007 06:21 PM

In both similations the dark side faced the earth, as well as the light side.  I don’t think I understand any better than I did before.

Actually I think it is best to not regard any part of the moon as “light side” and “dark side”.

There is “near side” and “far side”.  Those remain fixed.  But what part of the moon is facing the sun is constantly changing.

Does the Earth have a “light side” and “dark side”?

People don’t usually appl those terms to the Earth they just say day and night.  The days and nights on the moon just happen to be 14 Earth days long.

psik

Well that is what blew my mind earlier.  IF what Doug said and what you are saying, then the moon does not spin on it’s axis like the earth does.  It only moves back and forth in a way where the northern hemisphere leans towards the sun and then when it tips back the southern hemisphere is towards the sun, but it doesn’t spin.  That makes no sense because in order to have even a little gravity it has to rotate on it’s axis, the way I understand it, and the moon has a little gravity or the astronauts would have floated right off the moon.

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Posted: 31 December 2007 09:39 AM   [ Ignore ]   [ # 40 ]
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Jackson - 31 December 2007 04:05 AM

When there is a new moon the side which is enjoying ‘night’ faces the earth and the point most directly facing earth is enjoying ‘midnight’—it has been 7 days since the sun set and 7 days before the sun rises.
              when there is a full moon the side which is now enjoying ‘day’ , and the point most directly facing earch is at ‘high noon’—for 7 days it has seen direct sun light and this will continue for another 7 days.

Now this is why I don’t always like science.  It makes it difficult to visualize and like I said before, it sounds like the moon doesn’t spin on its axis.

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Posted: 31 December 2007 09:49 AM   [ Ignore ]   [ # 41 ]
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GdB - 31 December 2007 06:30 AM

Here I have a quiz question for Mriana and George. In what season of the year does the full moon reaches its highest point?

GdB

The winter equinox?  I don’t know.  Um…

George said:

The day of the birth of our Lord, Jesus Christ.

Yeah!  What he said!  Let me get the book of astrotheology and get the exact day using dematria.  Yeah!  That works.  LOL

A quiz for you: why does the moon spin about its axis?

Does it really?  I am now confused about that one.  :-(

BTW, I’ve been sharing this thread with my son when he’s here and awake.  He thanked me for posting it and we’ve been discussing it.  Unfortunately, the visual similation he gave me was not much help.  He used 2 of my jars of moisterizes with a flashlight being the sun.  The smaller jar was the moon orbiting the sun.  Thing is, the way he did it, the little jar didn’t turn on it’s axis.  The name stayed facing the earth so that when it was on the back side of the earth it was getting some light from the sun (flashlight) and when it was between the earth and the sun (usually an eclipse, It hought) the other side got sunlight but the part (name side) facing the earth was dark..  1.gif  It makes even less sense now.  I should have stuck with my theory, which made more sense.

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Posted: 31 December 2007 10:22 AM   [ Ignore ]   [ # 42 ]
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Mriana - 31 December 2007 09:49 AM

A quiz for you: why does the moon spin about its axis?

Does it really?  I am now confused about that one.  :-(

BTW, I’ve been sharing this thread with my son when he’s here and awake.  He thanked me for posting it and we’ve been discussing it.  Unfortunately, the visual similation he gave me was not much help.  He used 2 of my jars of moisterizes with a flashlight being the sun.  The smaller jar was the moon orbiting the sun.  Thing is, the way he did it, the little jar didn’t turn on it’s axis.  The name stayed facing the earth so that when it was on the back side of the earth it was getting some light from the sun (flashlight) and when it was between the earth and the sun (usually an eclipse, It hought) the other side got sunlight but the part (name side) facing the earth was dark..  1.gif  It makes even less sense now.  I should have stuck with my theory, which made more sense.

Here’s another image:

There’s a tree in a field. A hunter has chased a squirrel onto the trunk of that tree. The squirrel runs to the opposite side of the tree, looking up into the canopy, with his little belly facing the tree. Like this:

S T————- H

The hunter begins stalking the squirrel clockwise around the tree; the squirrel decides to follow him around, all the time keeping upright and all the time keeping his little belly facing the tree-trunk.

Let an arrow point the direction in which the squirrel’s belly faces, and let ‘O’ stand in for the squirrel. Like this - pardon the dots, which dont’ have a purpose in the diagram:

. . . . . O
. . . . . |
. . . . . v
O—> Tree <—O
. . . . . ^
. . . . . |
. . . . . O

The squirrel has gone around the tree, but has it turned on its on spine? Well, yes, if you compare the squirrel to the field: If O is the squirrel, and he started out on the S side of the tree-trunk, and he then went clockwise, his little belly would first face N, then E, S, W, and back to facing N. So the squirrel did rotate on his spine. That rotation took exactly as long as his ‘revolution’ around the tree-trunk.

Let the squirrel be the Moon, the tree-trunk the earth, and the hunter the Sun. YOu have the situation for saying the Moon rotates on its axis while keeping the same face always turned towards us.

Here’s another thing to try. Hold up a quarter at arm’s length and get George (Washington, not our George) to face you. just turn around like that in front of a bright window. George is always facing you, yet his face is pointing N, W, S, E and N again. That’s the coin ‘rotating’ on its axis in comparison with the room. And of course, George’s face is sometimes getting full Sun when your back is to the window, and is dark in it’s ‘new’ phase when you’re facing the window.
Kirk

[ Edited: 31 December 2007 10:27 AM by inthegobi ]
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Posted: 31 December 2007 11:02 AM   [ Ignore ]   [ # 43 ]
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Have a look at this simulation HERE

The green dotted line indicates the moon rotating about its axis. It rotates about its axis one round (360 degrees) in about 30 days which is also the time it takes to complete one revolution around the earth. Because of this synchronization, we can only see one side of it, the lighted up side.

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Posted: 31 December 2007 11:14 AM   [ Ignore ]   [ # 44 ]
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Mriana - 31 December 2007 09:49 AM

A quiz for you: why does the moon spin about its axis?

Does it really?  I am now confused about that one.  :-(

I hope I don’t complicate this by taking a stab at explaning this confusing subject.

If you watch the first video Brennen linked, the moon starts to the right side of the earth in a top view (could also be a bottom view).

To explain how no spin would be different:  Draw an imaginary line through the moon pointing at the earth, parallel to the bottom of your monitor.  Mentally lock the line in place so that it will stay parallel with the bottom of the monitor.  This will represents “no spin” and destinguishes the face of the moon we always see.  Now play the video, the moon goes counterclockwise until it is above the earth.  The imaginary line does not intersect with earth and always faces the sun with no spin.  If this was the relationship between the earth & the moon we would see all sides of the moon in one rotation, but this is not the case.

The case, Moon with spin: Because the moon does have spin (also in a counterclockwise motion) the imaginary line we drew will spin at exactly the right speed so that it is always pointing through the earth, or in other words, it is always facing the earth.

I hope I understood your question and this example is helpful.

The why part, we all know, is because the flying spaghetti monster said so.  wink

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Posted: 31 December 2007 11:36 AM   [ Ignore ]   [ # 45 ]
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kkwan - 31 December 2007 11:02 AM

Have a look at this simulation HERE

The green dotted line indicates the moon rotating about its axis. It rotates about its axis one round (360 degrees) in about 30 days which is also the time it takes to complete one revolution around the earth. Because of this synchronization, we can only see one side of it, the lighted up side.

In this similation it turned - the three dots (creators) were facing the earth and then they aren’t, thus that would mean we do see the opposite side.

Retrospray, as much as don’t as a rule find parody funny, the FSM makes more sense.  LOL  Now, if, as Geo. Carlin mentions in one of his stand-ups, a woman made the universe, it would not be so screwed up and confusing.  LOL It would all make sense.

BTW, I think my abstract reasoning has been stunted by my upbringing too.  I did my sons a BIG favour I think- theirs is not stunted, at least not severly or profoundly.  :-(

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