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Don J
2012-Sep-08, 03:41 AM
http://www.youtube.com/watch?v=zBlAGGzup48
Only 15 sec video
Longer version here:
http://www.youtube.com/watch?v=-NH5yK3ZN54
This simple animation was created by Nassim Haramein and The Resonance Project Foundation

Description
-"Many of us have been taught about how the solar system works by viewing a physical model that has the sun in the middle with the planets going around and around in a simple circular orbit without properly accounting for the motion of the sun (aprox. 450,000 miles per hour).
Because the both sun and the galaxy are moving through space, the Earth spirals an incredible distance through space in a year's time. How far the Earth moves depends on the reference point you are using for something "stationary" or "backgroud" even though all objects in the universe are in motion.

The Earth rotates at 0-1040 mi/hr (depends on latitude)
The Earth orbits the sun at aprox. 66,629 mi/hr
The sun orbits the galactic center at aprox. 447,000 mi/hr

In just considering how fast the sun is moving, we know the Earth travels at least 3,918,402,000 miles in a years time! (as it also orbits around the sun)

Total speed of the Earth moving through space is difficult to approximate do to the combination of motions.
Using Cosmic Microwave Background (CMB) radiation it is estimated the total motion of the Earth through space is aprox. 1,342,000 mi/hr
Or 11,763,972,000 miles in 1 year!
(which is still only 0.2% the speed of light!)

The old model might make one picture being back where you started after a year of time has past, when in fact, you are over 11 BILLION miles from where you were a year ago!

I hope this video helps people to visualize what the motion of the Earth in our solar system looks like."-

Does that description and video is conform to the motion of the solar system through the Milky Way ?If not why ?

Solfe
2012-Sep-08, 04:34 AM
I am not an expert, but it depends on your frame of reference. Going around the sun once a year is easy enough to picture. To have the whole solar system moving, is more accurate but where do you draw the line? The sun is going around the center of the galaxy and bobbing up and down though the galactic plane and the solar system is tilted at an angle to the plane of the galaxy. That is a mouthful to say the least.

Tensor
2012-Sep-08, 05:24 AM
Don, not sure if it conforms to the motion through the Milky Way as there are no other stars to compare it to. There are a couple of minor things that are wrong. The video has the motion of the sun as a straight line, but path of the sun would be curved, as it's motion around the Milky Way is a curved path, and they don't indicate the oscillatory motion of the sun's path as it moves from below the galactic plane to above and then to back below in a 30 million year period. And those motions would alter the motion of the spiral each of the planets follow.

I wouldn't normally nit pick those two, but the video nitpicks not teaching the planets as moving through space as a spiral. After all, the various aids to visualize the solar system compare the various planets in reference to the position of the sun, which does not need to include the spiral motion of the planets, just the two dimensional orbits. And why don't they mention the spirals of all the satellites around all the different planets? Those satellites have an even more complicated spiral, orbiting their primary, which is orbiting the sun. Not to mention the spirals of the globular clusters and satellite galaxies around the Milky Way, or the spirals M31 and the Milky Way make as they orbit their common center of gravity and their motions carry them toward Centaurus

It's interesting to note that I learned about the spiral motion of the planets back in fifth grade, some 45 years ago. So I'm not sure why this group is so surprised about the spiral motion and claims it's not taught.

Hornblower
2012-Sep-08, 01:37 PM
In my opinion, Mr. Haramein's presentation is technically valid but his saying that it is "wrong" to say that the planets are orbiting the Sun is pedantic and inappropriate. Most preteen pupils are not far enough advanced in the mathematical principles to easily make sense of these compound motions, and could be overwhelmed by too much all at once.

We should teach our pupils about frames of reference, provided we are giving them the necessary mathematical prerequisites. We should remind them that there is no absolutely stationary frame of reference, and that it is mathematically valid to choose whatever frame is best suited for the task at hand. We can start with treating the Moon as orbiting the Earth, and then progress to having the Earth/Moon combination orbiting the Sun. With some more advancement we can have the Earth/Moon/Sun combination orbiting the center of the galaxy. A small mechanical orrery mounted on the edge of a carousel would be a good visual aid.

Don J
2012-Sep-09, 06:10 PM
In my opinion, Mr. Haramein's presentation is technically valid but his saying that it is "wrong" to say that the planets are orbiting the Sun is pedantic and inappropriate.

I think he is more nuanced in his explanation than just saying it is "wrong"...
From Mr. Haramein's presentation excerpt from text under the long video:
http://www.youtube.com/watch?v=-NH5yK3ZN54
"Earth Is Not Orbiting The Sun in the way we were taught
Here we find an understanding of Why the Earth & our solar system do not actually orbit the Sun as taught, "Rather", We follow or better still, are dragged by the Sun in a Spiral Pattern through the universe & time.

This video offers explanations how, besides spinning on its axis and rotating as if going 'Around' the Sun, the Earth is shown to 'Follow' the Sun's movement through the Milky Way galaxy, in a continuous Spiral, not a Flat elliptical plane, thus we find a 3D universe as opposed to the accepted 2D."



Most preteen pupils are not far enough advanced in the mathematical principles to easily make sense of these compound motions, and could be overwhelmed by too much all at once.

I agree.


We should teach our pupils about frames of reference, provided we are giving them the necessary mathematical prerequisites. We should remind them that there is no absolutely stationary frame of reference, and that it is mathematically valid to choose whatever frame is best suited for the task at hand. We can start with treating the Moon as orbiting the Earth, and then progress to having the Earth/Moon combination orbiting the Sun. With some more advancement we can have the Earth/Moon/Sun combination orbiting the center of the galaxy. A small mechanical orrery mounted on the edge of a carousel would be a good visual aid.
Or a good video animation can do the work.

George
2012-Sep-09, 08:26 PM
If he is building a time machine to get back to where we were, he is on the right track.... kinda. Adding the motion of the Solar system through space is more accurate than ignoring it, but there a many other motions involved as well. The Earth's motion around the Sun is not circular, the Milky Way moves in a complex motion due to the gravity of the Local Group. The Local Group is also in a relative motion with the Hubble Flow. A mother's womb from the past is in a complex spiral motion relative to the Sun due to the Earth's rotation rate, which varies a tiny amount each day, not to mention the complexity of her travels with the father even if he follows her directions minimizing the ziggidy-zag of the trip.

His statement that the Earth is not orbiting the Sun is unfair since all orbiting is relative, and relative to the Sun, the Earth does orbit the Sun. [It does not orbit a yellow Sun, however. :) ] The empirical evidence for this abounds, contrary to his claim.

The suggestion that somehow our DNA and our evolution is embeded upon the spiral formed in the vacuum traveled is too weird for me.

Otherwise, his delivery and music are nice, and the video showing the orbital spirals as we travel many "millions" (??) of miles each time we go around the galaxy is enjoyable.

Jens
2012-Sep-10, 01:07 AM
You can also mention that the galaxy is moving through space, so there is an even higher layer. Maybe our galaxy cluster is moving compared to others.

antoniseb
2012-Sep-10, 01:16 AM
You can also mention that the galaxy is moving through space, so there is an even higher layer. Maybe our galaxy cluster is moving compared to others.
DonJ mentions that in his OP... in the section where he mentions the CMB... and then calls 11 trillion miles per year 11 billion miles per year (perhaps using the archane system in which a billion is a million millions, as opposed to the usual system today in which a billion is a thousand millions).

kzb
2012-Sep-10, 05:50 PM
>The sun orbits the galactic center at aprox. 447,000 mi/hr

That's actually slower than the IAU standard (490,00mph), and even slower than recent estimates of c. 540,000mph. Still, it's an interesting fact to people who have not considered it before, that we are orbiting the galaxy 8 times faster than we are orbiting the sun.

Cougar
2012-Sep-10, 11:11 PM
Description
-"Many of us have been taught...

Since this is presumably about educating people, I suppose the "miles" and "miles per hour" units are the units that are familiar to the target audience. But there's a reason astronomers use parsecs or lightyears or meters (or km) per second. Do you have a good sense how fast 450,000 miles per hour is? The unit might be familiar, but the huge number in front of it saps all meaning from the familiar units, other than "oh, that's really fast." You might as well say km/sec. "Miles" and "miles per hour" are essentially never used when talking about astronomical things. If Nassim Haramein wants to be educational, use the units that astronomers typically use, not the units used by NASCAR. :doh:

Jerry
2012-Sep-11, 12:16 AM
... not the units used by NASCAR. :doh:

Whooh! I've driven a LOT faster than I ever before realized! I wonder, if by pointing out to the arresting officer that we are all exceeding the posted speed limit by a fantastic amount, I can get away with just a caution.

kzb
2012-Sep-11, 11:41 AM
Question (somewhat off the original purpose of the thread): is it possible to compute a position in the universe where the motion relative to the CMB rest frame is zero?

Don J
2012-Sep-11, 06:08 PM
If Nassim Haramein wants to be educational, use the units that astronomers typically use, not the units used by NASCAR. :doh:
His video animation is destined to the general public so he use units that the general public can understand.I bet that if he use term like parsecs or other units that astronomers typically use the general public which are not educated in astronomy will get lost by these astronomical units unknown to them.

Squink
2012-Sep-11, 09:23 PM
http://www.youtube.com/watch?v=zBlAGGzup48
Only 15 sec video
...
The sun orbits the galactic center at aprox. 447,000 mi/hr

Sun's poles are nearly perpendicular to the plane of galaxy, Ecliptic is along galactic plane, which is also direction of sun's orbit around galaxy.
The video shows sun moving in the direction of one of its poles, with ecliptic near perpendicular to galactic plane.
An observer sitting at galactic center should see the planets describe epicycle like curves, not helices.

George
2012-Sep-12, 12:47 AM
Question (somewhat off the original purpose of the thread): is it possible to compute a position in the universe where the motion relative to the CMB rest frame is zero?
The CMB dipole reveals a 369 kps speed with the Hubble flow, so something with an opposite vector might be your ride going down the frog & toad. [Feel free to mock my English humour a attempt.]

More here (http://cosmoquest.org/forum/showthread.php/104144-What-s-our-Hubble-Flow-Vector?p=1734199#post1734199).

kzb
2012-Sep-12, 11:52 AM
The CMB dipole reveals a 369 kps speed with the Hubble flow, so something with an opposite vector might be your ride going down the frog & toad. [Feel free to mock my English humour a attempt.]

More here (http://cosmoquest.org/forum/showthread.php/104144-What-s-our-Hubble-Flow-Vector?p=1734199#post1734199).

It just struck me it ought to be possible to triangulate a "centre of the universe" using the velocities and vectors of galaxy groups relative to the CMB. But then I realised, there are galaxies 12 billion light years away whose locally-measured velocity relative to the CMB is muchthe same as ours. So I guess it doesn't work.

Jeff Root
2012-Sep-12, 10:18 PM
I watched the short video but not the long one because I
don't have a broadband connection.

I agree in general principle with Squink: The plane of
the orbits of the planets (the ecliptic) is not perpendicular
to the direction of motion of the Solar System around the
center of the Milky Way. Nor is it perpendicular to the
direction of motion of the Solar System relative to the
nearby stars. It would take me some hours of study to
determine the exact actual direction, which I should do
eventually, but not today. So if the spirals are meant to
depict either the motion of the Solar System around the
galaxy or its motion relative to the nearby stars, it is not
very accurate.

I disagree strongly with some of the statements quoting
Nassim Haramein:



Earth Is Not Orbiting The Sun in the way we were taught.
Here we find an understanding of Why the Earth & our
solar system do not actually orbit the Sun as taught,
"Rather", We follow or better still, are dragged by the
Sun in a Spiral Pattern through the universe & time.
Earth is orbiting the Sun. Earth is also orbiting the
Solar System's Barycenter. Earth, along with the rest
of the Solar System, is also orbiting the Milky Way.
Saying that Earth is not orbiting the Sun is just wrong.
There is more to Earth's motion than its orbit of the
Sun, but it is completely correct to say that it orbits
the Sun, and incorrect to say that it does not.

In trying to correct what he characterizes as an error,
he commits a much worse error.

Certainly the orbits of planets around the Sun can be
viewed as spirals from a wide range of vantage points.
Those spirals are no more correct than elliptical orbits.
They are in fact more misleading, in giving the wrong
impression that location in space is absolute rather
than relative.

The planets do not follow the Sun and are not dragged
by the Sun. Both of those notions are utterly wrong.
All the bodies of the Solar System are on trajectories
around the galaxy which are very similar. They are
gravitationally bound together, which is why they orbit
the Sun, but each body orbits the galaxy on its own.
They are not dragged. Collectively, we can say the
Solar System orbits the galaxy. Implying that the Sun
orbits the galaxy and the planets are dragged along
with it is terribly misleading.

-- Jeff, in Minneapolis

Jerry
2012-Sep-13, 07:54 AM
I agree with Jeff completely - the author could have used the spiral notation to illustrate the concept without the obvious miss statements.

He also left out the Turtles on the bottom.

Don J
2012-Sep-14, 03:41 AM
I disagree strongly with some of the statements quoting
Nassim Haramein:


Earth Is Not Orbiting The Sun in the way we were taught.
Here we find an understanding of Why the Earth & our
solar system do not actually orbit the Sun as taught,
"Rather", We follow or better still, are dragged by the
Sun in a Spiral Pattern through the universe & time.

Earth is orbiting the Sun. Earth is also orbiting the
Solar System's Barycenter. Earth, along with the rest
of the Solar System, is also orbiting the Milky Way.
Saying that Earth is not orbiting the Sun is just wrong.

But he is not saying that Earth is not orbiting the Sun, here the nuance:
"Earth Is Not Orbiting The Sun in the way we were taught."

-"Many of us have been taught about how the solar system works by viewing a physical model that has the sun in the middle with the planets going around and around in a simple circular orbit without properly accounting for the motion of the sun (aprox. 450,000 miles per hour).
Because the both sun and the galaxy are moving through space, the Earth spirals an incredible distance through space in a year's time"



There is more to Earth's motion than its orbit of the
Sun, (snip)
Certainly the orbits of planets around the Sun can be
viewed as spirals from a wide range of vantage points.

That is what the video is showing:
http://www.youtube.com/watch?v=zBlAGGzup48


Those spirals are no more correct than elliptical orbits.

I don't think he exclude the elliptical motion of the planets around the sun in his demonstration.


They are in fact more misleading, in giving the wrong
impression that location in space is absolute rather
than relative.

I don't think he is suggesting that location in space is absolute rather
than relative.
quoting Nassim Haramein:
-"How far the Earth moves depends on the reference point you are using for something "stationary" or "background" even though all objects in the universe are in motion
Total speed of the Earth moving through space is difficult to approximate do to the combination of motions.
Using Cosmic Microwave Background (CMB) radiation it is estimated the total motion of the Earth through space is aprox. 1,342,000 mi/hr
Or 11,763,972,000 miles in 1 year!
(which is still only 0.2% the speed of light!)-


The planets do not follow the Sun and are not dragged
by the Sun. Both of those notions are utterly wrong.
All the bodies of the Solar System are on trajectories
around the galaxy which are very similar. They are
gravitationally bound together, which is why they orbit
the Sun, but each body orbits the galaxy on its own.
They are not dragged. Collectively, we can say the
Solar System orbits the galaxy. Implying that the Sun
orbits the galaxy and the planets are dragged along
with it is terribly misleading.

-- Jeff, in Minneapolis
So, what is the cause of the spiraling motion of the planets and satellites (see Tensor's post 3)?

grapes
2012-Sep-14, 04:01 AM
Earth is also orbiting the
Solar System's Barycenter.

The earth's orbit is complicated by the other planets, but it doesn't really orbit the barycenter of the solar system--in the same way, the space shuttle doesn't orbit the earth-moon barycenter.

Hornblower
2012-Sep-14, 10:18 AM
snip...

So, what is the cause of the spiraling motion of the planets and satellites (see Tensor's post 3)?

The Sun's gravity. If we could magically turn it off, the planets would go on orbiting the galaxy in similar but not identical orbits, and would disperse.

Jeff Root
2012-Sep-14, 12:45 PM
Earth is also orbiting the Solar System's Barycenter.
The earth's orbit is complicated by the other planets,
but it doesn't really orbit the barycenter of the solar
system--in the same way, the space shuttle doesn't
orbit the earth-moon barycenter.
My statement was a simplification.

The Earth-Moon barycenter is inside the Earth, so the
Space Shuttle did orbit the Earth-Moon barycenter when
it was in orbit. Now the shuttles just go around that
barycenter about once a day.

Mercury is inside Earth's orbit, so Earth orbits Mercury.
The Solar System's barycenter is inside Earth's orbit,
so Earth does orbit the Solar System's barycenter.

But Earth really, truly orbits the Sun-Mercury-Venus
barycenter. Perhaps I should not have said it orbits
the Solar System's barycenter. Just the barycenter
of the "inner" part of the Solar System.

-- Jeff, in Minneapolis

Jeff Root
2012-Sep-14, 01:48 PM
I disagree strongly with some of the statements quoting
Nassim Haramein:


Earth Is Not Orbiting The Sun in the way we were taught.
Here we find an understanding of Why the Earth & our
solar system do not actually orbit the Sun as taught,
"Rather", We follow or better still, are dragged by the
Sun in a Spiral Pattern through the universe & time.
Earth is orbiting the Sun. Earth is also orbiting the
Solar System's Barycenter. Earth, along with the rest
of the Solar System, is also orbiting the Milky Way.
Saying that Earth is not orbiting the Sun is just wrong.
But he is not saying that Earth is not orbiting the Sun,
here the nuance:
"Earth Is Not Orbiting The Sun in the way we were
taught."
But it is orbiting the Sun in the way we were taught.



-"Many of us have been taught about how the solar
system works by viewing a physical model that has
the sun in the middle with the planets going around
and around in a simple circular orbit without properly
accounting for the motion of the sun (aprox. 450,000
miles per hour).
What is the motion of the Sun relevant to?
That was not a typo. Unless you have some specific
reason to include the motion of the Sun relative to
other stars, it has no relevance to the elliptical orbits
of the planets.



Because the both sun and the galaxy are moving
through space, the Earth spirals an incredible distance
through space in a year's time"
Unless you have some specific reason for including the
motions of the Sun relative to other stars and of the
galaxy relative to other galaxies, those motions are
irrelevant to an accurate description of Earth's motion.

The fact that Earth orbits the Sun is widely stated and
widely known.

The fact that the Solar System orbits the center of the
Milky Way galaxy is widely stated and widely known.

The fact that the Milky Way is moving relative to other
galaxies is widely stated and widely known.

So it is simply false that "Earth Is not orbiting the
Sun in the way we were taught."




They are in fact more misleading, in giving the wrong
impression that location in space is absolute rather
than relative.
I don't think he is suggesting that location in space is
absolute rather than relative.
When he says spirals are a more accurate representation
of Earth's motion than elliptical orbits, he is implying
that location in space is absolute rather than relative.



quoting Nassim Haramein:
"How far the Earth moves depends on the reference point
you are using for something "stationary" or "background"
even though all objects in the universe are in motion
Total speed of the Earth moving through space is difficult
to approximate do to the combination of motions.
Using Cosmic Microwave Background (CMB) radiation it is
estimated the total motion of the Earth through space is
aprox. 1,342,000 mi/hr Or 11,763,972,000 miles in 1 year!
(which is still only 0.2% the speed of light!)-

So, what is the cause of the spiraling motion of the
planets and satellites (see Tensor's post 3)?
As Haramein says, it depends on the reference point
you are using. Use a reference point which is stationary
relative to the Sun, and there is no spiraling motion,
just elliptical orbits. If you want to use a different
reference point, you can, and it may be useful in some
situations, but there is no general reason to do so.

-- Jeff, in Minneapolis

Don J
2012-Sep-14, 06:59 PM
As Haramein says, it depends on the reference point
you are using. Use a reference point which is stationary
relative to the Sun, and there is no spiraling motion,
just elliptical orbits.
-- Jeff, in Minneapolis
Can you give an example of a reference point which is stationary
relative to the Sun ?


If you want to use a different
reference point, you can, and it may be useful in some
situations, but there is no general reason to do so.

Point taken.But it is not bad to extend some notion outside the 2D perception we were taught."

Hornblower
2012-Sep-14, 07:03 PM
Can you give an example of a reference point which is stationary
relative to the Sun ?

Point taken.

Yes, its center.

Don J
2012-Sep-14, 07:10 PM
Yes, its center.
I was asking for something other that the (center of the) Sun.
OK, so outside of that particular point everything is in movement.

grapes
2012-Sep-14, 07:45 PM
My statement was a simplification.

The Earth-Moon barycenter is inside the Earth, so the
Space Shuttle did orbit the Earth-Moon barycenter when
it was in orbit. Now the shuttles just go around that
barycenter about once a day.

The shuttle always did go around me, and you, still does. But that is different than saying the shuttle orbits me, or you. No?


Mercury is inside Earth's orbit, so Earth orbits Mercury.
The Solar System's barycenter is inside Earth's orbit,
so Earth does orbit the Solar System's barycenter.

But Earth really, truly orbits the Sun-Mercury-Venus
barycenter. Perhaps I should not have said it orbits
the Solar System's barycenter. Just the barycenter
of the "inner" part of the Solar System.What is meant by "truly" there?

Why wouldn't you say the Earth truly orbits the sun-jupiter barycenter too?

Noclevername
2012-Sep-14, 10:12 PM
My statement was a simplification.

The Earth-Moon barycenter is inside the Earth, so the
Space Shuttle did orbit the Earth-Moon barycenter when
it was in orbit. Now the shuttles just go around that
barycenter about once a day.

Mercury is inside Earth's orbit, so Earth orbits Mercury.
The Solar System's barycenter is inside Earth's orbit,
so Earth does orbit the Solar System's barycenter.

But Earth really, truly orbits the Sun-Mercury-Venus
barycenter. Perhaps I should not have said it orbits
the Solar System's barycenter. Just the barycenter
of the "inner" part of the Solar System.

-- Jeff, in Minneapolis

My understanding is that each of those things have their own gravitational relationships and thus their own barycenter. There is no "barycenter of the Solar System", because the barycenter is relative to each relationship. The Shuttle orbited the barycenter between the Shuttle and Earth.

Jeff Root
2012-Sep-14, 11:11 PM
Can you give an example of a reference point which is
stationary relative to the Sun ?
What do you mean by "an example of a reference point"?
An object? I don't know of any such object.



Point taken. But it is not bad to extend some notion
outside the 2D perception we were taught."
I was taught that the orbits of the planets are not
exactly coplanar, which is crucial in describing motion
of the planets through Earth's sky and predicting
occultations and eclipses. I don't remember when I
learned that the Solar System orbits the galaxy, or
that the ecliptic plane is not aligned with the plane
of the galaxy (I never thought that), but it was
certainly before age ten for both. The notion of the
planets spiralling around the center of the galaxy is
a pretty obvious inference with very little practical
or theoretical significance.

-- Jeff, in Minneapolis

Hornblower
2012-Sep-15, 12:04 AM
My understanding is that each of those things have their own gravitational relationships and thus their own barycenter. There is no "barycenter of the Solar System", because the barycenter is relative to each relationship. The Shuttle orbited the barycenter between the Shuttle and Earth.

My bold. Oh yes there is, and it is the only such point for which an inertial frame of reference can be found in which it is virtually stationary. It just does not coincide with the focus of the best-fit ellipse for the orbit of anything in the inner Solar System.

We could quibble with words endlessly when arguing about the concept of what it means to "orbit a barycenter" in a multibody system. Let's stick to the language of mathematics and avoid this verbal stuff.

Nothing in the Solar System moves in a perfect ellipse, let alone one with a focus fixed at any particular barycenter or any other type of central point. For a small body very close to the Sun, the best-fit ellipse will have a focus very close to the Sun's center. For a small body far beyond Neptune's orbit, the best fit will be closer to the overall Solar System barycenter, though never perfectly coinciding with it. For intermediate cases, the orbit will wiggle and jiggle like a bowl of jelly, and there will be no fixed best-fit ellipse from one circuit to the next.

Jeff Root
2012-Sep-15, 12:53 AM
I'm basically saying what Hornblower said. I wrote
all below except the final sentence before he posted.



The shuttle always did go around me, and you,
still does. But that is different than saying the
shuttle orbits me, or you. No?
Yes, but the Shuttle used to orbit us, not just go
around us.



What is meant by "truly" there?
Same as you meant by "really" when you said
"... it doesn't really orbit the barycenter ..."
When I wrote "really, truly" I had in mind little kids
who are struggling to differentiate between fiction
and fact. One in particular who seemed not to know
what information to trust.



Why wouldn't you say the Earth truly orbits the
sun-jupiter barycenter too?
Because I'm not sure what the correct statement is.

I know that one focus of Earth's elliptical orbit is
approximately at the center of the Sun. I also know
that all the other matter in the Universe affects that
orbit, and thus the location of the focus. Obviously
all the matter inside Earth's orbit acts to increase
Earth's centrepital acceleration. The sum is the
barycenter of the "inner" part of the Solar System.

But all the matter outside Earth's orbit also affects
Earth's centrepital acceleration. The directions of
their forces cancel each other almost perfectly, so
for many purposes they can be and are ignored.
I don't how to describe it both simply and correctly.
If everything outside Earth's orbit was a perfectly
uniform shell, the barycenter of the rest would be
the the nearest thing to an exact focal point of
Earth's elliptical orbit.

-- Jeff, in Minneapolis

Jeff Root
2012-Sep-15, 01:05 AM
My understanding is that each of those things have
their own gravitational relationships and thus their
own barycenter.
Yes.



There is no "barycenter of the Solar System", because
the barycenter is relative to each relationship.
As Hornblower said, there is a barycenter of the Solar
System. I've seen a diagram showing how it changes
over time as the planets move about.



The Shuttle orbited the barycenter between the Shuttle
and Earth.
This showed that I erred in saying that Earth orbits the
barycenter of the Sun, Mercury, and Venus. It is actually
the barycenter of the Sun, Mercury, Venus, and Earth.

-- Jeff, in Minneapolis

Robert Tulip
2012-Sep-15, 04:30 AM
The solar system orbits the galaxy in about quarter of a billion years, so our oldest DNA has gone around the galaxy about sixteen times since the origin of life on earth.

The solar system barycenter inscribes a perfect arc around the galaxy, and the sun wobbles from side to side of this path, in a movement primarily driven by the regular patterns of the gas giants. I discuss the movement of the sun against the SSB at http://cosmoquest.org/forum/showthread.php/80362-Spiral-Model-of-Solar-System quantifying the effects of the planets.

"Spiral" might not be the best word to describe a helix, as spirals are usually like a clock spring whereas a helix has a constant radius. But helix is seen as a form of spiral, in the sense that the DNA double helix is sometimes said to have a spiral structure.

The movement of the solar system with respect to the galaxy is discussed at these threads
http://cosmoquest.org/forum/showthread.php/80827-Solar-System-Angle-to-Galaxy
http://cosmoquest.org/forum/showthread.php/84591-Direction-of-sun

eburacum45
2012-Sep-16, 11:35 AM
The solar system barycenter inscribes a perfect arc around the galaxy,
Not really perfect; it bounces up and down through the plane of the Galaxy every sixty-five million years or so, and will be slightly perturbed by other objects in the galaxy; so it will never come back to exactly the same place twice with respect to the Galaxy.