Why is North up? Bib. Ast.#27

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bobw

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<blockquote><font class="small">In reply to:</font><hr /><p>And one final question (for now): How is the solar system eccliptic aligned with the galactic eccleptic?<p><hr /></p></p></blockquote><br /><br />http://www.mreclipse.com/Astrophoto/SS97galleryC.html<br /><br />Southern Sky & Milky Way (Lake Titicaca, Bolivia)<br />8mm f/2,8 Nikkor Fisheye, Fuji Super G 800 Plus, 30 minutes @ f/2.8 <br />Photo 1997 by Fred Espenak<br /><br />A 180<sup>o</sup> fish-eye lens captures the entire sky with the center of the Milky Way passing near the zenith. The bright star to the left is actually the planeet Jupiter.<br /><br />The milky way runs from top to bottom. We are in the outskirts looking in. The plane of the galaxy is up and down in the sky when I look at it. The colored dotted line is the path that Jupiter takes, the path that Mars takes, the path the Sun takes, the path the moon takes, it is the plane of the ecliptic. It goes side to side. One goes up and down, the other goes side to side. Neither one could be used as the base of a cone that points north. <div class="Discussion_UserSignature"> </div>
 
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bobw

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I agree with you. Up is up. The zenith. The surface normal vector to the earth sphere at my location. Up... I just don't understand this whole mess. Your post is like a breath of fresh air. <div class="Discussion_UserSignature"> </div>
 
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mooware

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<br />Your post about which way being "up" relative to where you are, makes perfect sense to me.<br /><br />
 
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newtonian

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Bobw- Excellent. So, clearly, earth's north rotational pole points in a different direction that what would be up from the Milky Way eccliptic - and that is quite an angle.<br /><br />Thank you for the image- a picture is worth a thousand words!<br /><br />Now, I am still unclear about the angle of north from earth's rotational pole compared with the solar system eccliiptic.<br /><br />From Calli's post on the related rotational thread, my mental picture has earth's north rotational pole pointed at a constant angle relative to the plane of the solar system eccliptic north.<br /><br />Am I correct???? <br /><br />I had earlier thought it varied during earth's revolution, but now I see it does not.<br /><br />So then, my next question would logically be: does north point to the same location in our universe year round????<br /><br />BTW - please ignore the magnetic pole- I am talking about the rotational axis.
 
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newtonian

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bobw- Try to understand. Or, take it with a sense of humor:<br /><br />er - what's up doc? <br /><br />It might help if you zero in on my last question:<br /><br />Does the rotational axis north pole on earth always have the same angle to the solar system eclliptic and therefore does the north rotational pole always point to the same location (i.e.: direction) in our universe?<br /><br />The obvious alternative would be that the solar system eccliptic north points in a different direction during its revolving around the Milky Way or during its oscillation in relation to the galactic eccliptic.
 
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CalliArcale

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<blockquote><font class="small">In reply to:</font><hr /><p>Does the rotational axis north pole on earth always have the same angle to the solar system eclliptic and therefore does the north rotational pole always point to the same location (i.e.: direction) in our universe? <p><hr /></p></p></blockquote><br /><br />Within the course of a year, yes, it does maintain the same angle. That's why the North Star is always Polaris, no matter what season it is.<br /><br />However, it doesn't maintain the same angle indefinitely. 2,000 years ago, Polaris was not the north star, and this wasn't just because the stars do in fact move. It's because the Earth wobbles. The phenomenon is called <i>precession</i>, and you can watch a spinning top slowly precess around in a similar way. It's slow enough that we don't perceive it. It takes many generations for it to become significant, but it is nevertheless a real phenomenon.<br /><br />I don't recall which star was the north star in Biblical times, though I know I've seen diagrams showing it. I think it was a very dim star, and as such, may not even have been recognized as the north star, although the ancients did realize that some stars never set. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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newtonian

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Calli - Yes, thank you. Does revolving around the Milky Way every 220 million years also change north in respect to the universe - in view of the fact that earth's eccliptic, and also the solar system eccliptic, is at an angle in respect to the galactic eccliptic?<br /><br />BTW- I am having trouble getting a mental picture of what we look like from the outside, since astronomy observations are actually looking from the inside out!<br /><br />Is there any website showing computer simulations of what we would look like from the outside in?<br /><br />BTW - Polaris is within our galaxy. I'm trying to get a mental picture looking at our earth from beyond our galaxy - e.g. at a point near our visibility horizon.<br /><br />Of course, at Bible times is variable since it was written over a period of over 1600 years. <br /><br />My interest is zeroing in on 1513 BCE or so, around when Job was written by Moses.<br /><br />Over that short a period of time ago (astronomically speaking) I doubt revolution in the Milky Way would have much effect.<br /><br />BTW - does relative motion of Polaris during that time have a perceivable effect?<br /><br />Oh - my specific question - where would north point to in 1513 BCE?<br /><br />E.g. - where would Hubble point if doing a deep field survey of that location near our visibility horizon?<br />Isn't there a thread on Precession?<br />
 
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CalliArcale

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<blockquote><font class="small">In reply to:</font><hr /><p>BTW- I am having trouble getting a mental picture of what we look like from the outside, since astronomy observations are actually looking from the inside out! <p><hr /></p></p></blockquote><br /><br />You and me both! It's kind of mind-bending. <img src="/images/icons/wink.gif" /> I like trying to visualize it, but it's not intuitive. It's really amazing to discover how firmly our minds are fixed to this perception of the world around us.<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>Is there any website showing computer simulations of what we would look like from the outside in? <p><hr /></p></p></blockquote><br /><br />I'm sure there are. Offhand I don't know of any, but I'll try to find some later. I do know that if you buy the software Starry Night or Deep Space Explorer you can get a startling look at the universe. It will let you see the Milky Way from Andromeda, for instance, or swoop past the Magellanic Clouds, or even zip far, far, far out into the distant reaches of the universe, to the most distant mapped galaxies.<br /><br />There are, however, holes. Large portions of the universe cannot easily be observed from Earth. In Deep Space Explorer, you can zoom out to see all mapped galaxies from the outside. There is a notable wasp-waist to the structure, centered on the Milky Way. Basically, it seems that there are no galaxies along the galatic plane! Which isn't true, of course. It's just that we can't observe them from Earth because the Milky Way itself gets in the way.<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>Of course, at Bible times is variable since it was written over a period of over 1600 years.<br /><br />My interest is zeroing in on 1513 BCE or so, around when Job was written by Moses. <p><hr /></p></p></blockquote><br /><br />I'll see if I can find anything. I'm sure somebody's already crunched the numbers to come up with a picture. The trick will be finding out if stel <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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newtonian

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Calli - Thank you. Yes, it is mind-bending, or mind-boggling.<br /><br />Sounds like a good reason to purchase said programs. I will consider it.<br /><br />No rush, but if you find something, it would be appreciated.<br /><br />Note that it seems North (and south) would be a more stable reference frame from beyond our galaxy to describe earth's position than east or west would be- for rotational reasons!
 
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CalliArcale

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I finally got around to reinstalling StarryNight Pro. Deep Space Explorer is a bit more intuitive for this kind of thing (seeing our solar system from the outside) and I don't remember how to make the orbits show up, but I did make a few JPGs that should help.<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>Note that it seems North (and south) would be a more stable reference frame from beyond our galaxy to describe earth's position than east or west would be- for rotational reasons!<p><hr /></p></p></blockquote><br /><br />You are correct. <img src="/images/icons/wink.gif" /> East and west are less meaningful in space. Something interesting to consider -- bodies which rotate synchronously can be said to have an east *pole* -- it's the leading point as the body goes around its parent. [eek]<br /><br />Now, and I apologize for the low resolution of these images (they're quick-and-dirty), but here's a picture of Earth as seen from an arbitrary point on Venus. It's hard to make out, but you can see Africa and Antarctica, so the south pole is to the top right. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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CalliArcale

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From another arbitrary point on Venus, taken at the same time (yesterday evening, as it happens), you can still see Africa and Antarctica, but now the south pole is to the bottom, and angled slightly. This angle has very little to do with the Earth's axial inclination, by the way -- it's mostly an artifact of the angle of the observer's head. In all of these pictures, "down" is defined as "towards the nearest horizon", just as it is for you and me looking up at the sky. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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CalliArcale

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Just for fun, here's the Earth as seen from Tycho Crater on the southern hemisphere of the Moon. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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CalliArcale

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And here's a view of our solar system as seen from the nearest star outside of it -- Rigil Kentaurus, or Alpha Centuari. Obviously it is magnified by a ludicrous amount. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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newtonian

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Calli - Excellent! It does show north can be down or to the side, at various angles. <br /><br />On the Biblical astronomy #27, I am speculating that north was up, not just for the writer (Moses, 1513 BCE) but perhaps also for the Author.<br /><br />As you seem to agree, east or west would not be suitable for 'up' for any reasonable amount of time- certainly not using 7,000 year long days.<br /><br />However, for my thought experiment, you can ignore the skewing from an observer located on a rotational body also revolving.<br /><br />You can assume earth's north is being used for comparison purposes in referencing.<br /><br />I.e. - the theoretical distant observer can be illustrated as standing vertical with head up equaling earth's north.<br /><br />Or compensating for the purposes of cross-referencing between the two points of reference. (like rotating the photo)<br /><br />Also, assume the observer is near the visibility horizon of our universe or from beyond that but with a line of sight intersecting the visibility horizon at a certain point.<br /><br />I'm not sure either of the scientific research conclusions, or the Biblical research conclusions- but here is a tentative educated guess:<br /><br />God is looking down on earth, and north is considered up. <br /><br />I recently learned that God's location is described as north of Israel.<br /><br />Now, with a date of 1513 BCE, and with north being up, and with the line of sight north of earth's average north that year, does this pinpoint a specific location for a Hubble deep field study?<br /> <br />Or is my thought experiment making my head spin beyond my perception at this late hour?<br />BTW - I note that viewing earth from this distance would be impossible by human observatories. We would be as an unreality, true to the description in Isaiah 40, from even the much shorter distance you last posted a model of!<br /><br />Thank you again, btw!
 
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nexium

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Caliarc gave Newtoniun a good answer.<br /> Stars farther away than 10% of the galaxy's radius generally are not naked eye visable as individual stars, and our sun would be barely visable at this distance with a powerful telescope.<br /> In two opposite directions we are just barely out of the galaxy at 1/10 th radius away. It is generally supposed that the Milky way galaxy looks a lot like the Androdomedia galaxy with our sun about 1/3 of the way from the center of the milky way galaxy.<br /> Generally Hubble can look at locations about 13 billion light years away in any direction other than the galaxy hub and disk. Neil
 
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kmarinas86

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How would it be possible to look through 4/3 of the Milky Way?
 
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nexium

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I don't know how you arrived at 4/3. I don't think it is possible. We are however looking through about 1/3 of the diameter of the Milky Way Galaxy when we look in the direction opposite the center of the Milky Way Galaxy. <br />We have however concluded (somehow) that there is a mini galaxy perhaps 200,000 miles away on the other side of the hub of the Milky Way Galaxy. Neil
 
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mooware

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<font color="yellow">"<br />I recently learned that God's location is described as north of Israel. "</font><br /><br />Maybe he lives in Siberia. lol..<br /><br />
 
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newtonian

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kmarinas86 and nexium - after a good laugh:<br /><br />Note that would be 4/3 of the radius looking through the center and out the other 'edge.'<br /><br />The confusion is caused by interchanging radius and diameter!<br /><br />Now, if we look north through our galaxy.....????<br /><br />And we need to have a good time<br /><br />reference
 
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newtonian

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mooware - yes, you are appealing to my sense of humor - the cold, hard facts!<br /><br />Seriously, I am aware it could simply be a figure of speech.<br /><br />Then again, perhaps not.<br /><br />I don't like assuming things - so I am exploring the possibilities.<br /><br />And things are looking up!<br /><br />Or, I am looking things up!<br />Or, I am looking at things looked up (as by Calli)!<br /><br />Calli - Seriously: Thank you. <br /><br />You all - Be sure to look up on Wednesday when our moon will be ecclipsed!
 
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CalliArcale

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No sweat. I needed an excuse to get Starry Night reinstalled on my laptop. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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newtonian

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Calli - No sweat? I wish!<br /><br />And since you said the word - boy has Louisiana been hot and humid this month! It will probably be the hottest October ever recorded.<br /><br />Gives one cause for favoring north!<br />Seriously - I will consider purchasing Starry Night.<br /><br />First, I have to figure out my new camera-phone!<br /><br />And watch the ecclipse!<br />
 
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