Page 5 of 6 FirstFirst ... 3456 LastLast
Results 121 to 150 of 172

Thread: Trojan

  1. #121
    Join Date
    Aug 2008
    Location
    Wellington, New Zealand
    Posts
    3,580
    Quote Originally Posted by Dave Lee View Post
    ...As long as the Center of mass is located in the arm, there is no ploblem with that.
    There is the problem that there is no "arm" in Orientation of the Earth, Sun and Solar System in the Milky Way

    There is the problem that the center of mass of the galaxy is about the center of the galaxy not any of its spiral arms. This is easy to understand. The center of mass of a uniform disk is its center. The center of mass of a uniform sphere is its center. The galaxy is basically a disk + a sphere thus its center of mass is roughly its center.

    ETA: the Sun's center of mass is inside the Sun but that just has to be a typo in your post.
    Last edited by Reality Check; 2018-Jan-10 at 09:25 PM.

  2. #122
    Join Date
    May 2005
    Posts
    7,764
    Quote Originally Posted by Dave Lee View Post
    Motion of Earth and Sun around the Milky Way

    Please look at the following diagram:

    https://www.physicsforums.com/thread...ky-way.888643/

    It shows a perfect image about the motions of The Earth and Moon while the Sun orbits the Galaxy.
    Read the comments. The person who created that picture is trying to understand the relationship of the solar system planets and moons and the galaxy. It's a nice looking picture, but they don't reveal what source they used in creating the picture, and they've made mistakes. In no way do they understand the math or the physics. They don't appear to have even taken high school geometry.

    Without a strong understanding of the physics and math, their conclusions are just wrong.
    With regards to the Earth:
    It is clear that the Earth is bobbing up and down while it orbits the Sun.
    Same issue with the Moon.

    With regards to the orbital Sun around the Milky way:
    Based on this diagram, it seems that the upwards orbital sine wave (with reference to the galactic plane) is almost double in its amplitude comparing to the downward sine wave.
    That shows that the Sun' center of mass is not located directly at the galactic plane, but somewhere higher.
    Therefore, the Sun orbits around this Center of mass while it continue its orbital motion around the galaxy.
    As long as the Center of mass is located in the arm, there is no ploblem with that.
    That's just nonsense.

    The sun's center of mass is located very near the center of the sun, and nothing changes that.

  3. #123
    Join Date
    Oct 2009
    Location
    a long way away
    Posts
    10,030
    Quote Originally Posted by Dave Lee View Post
    It shows a perfect image about the motions of The Earth and Moon while the Sun orbits the Galaxy.
    How do you know it is "perfect"? Apart from anything else, the it is ludicrously out of scale.

    I really don't think you can draw any rational conclusion from a crude sketch like that.

    With regards to the Earth:
    It is clear that the Earth is bobbing up and down while it orbits the Sun.
    Not at all. It represents the Earth moving in a smooth ellipse. It doesn't show it bobbing up and down throughout its orbit.

    Based on this diagram, it seems that the upwards orbital sine wave (with reference to the galactic plane) is almost double in its amplitude comparing to the downward sine wave.
    So maybe it is not a very accurate diagram.

    By the way, post 19 in that thread explains the "pendulum motion" of stars through the galactic disk based on the same physics that people here have tried to explain. So if you think hat thread is much more reliable than this one, maybe you should take not of that.

  4. #124
    Join Date
    Sep 2015
    Posts
    302
    Thanks for the questions.
    However, the following one is THE most important (as I see it).

    Quote Originally Posted by Reality Check View Post
    Show that a "Zig Zag orbiting path in three dimensions by only one orbital Cycle" is physically impossible.
    There is no Zig zag orbiting by Newton or Kepler.

    Please see the following:

    https://en.wikipedia.org/wiki/Kepler...ical_Orbit.png

    https://en.wikipedia.org/wiki/Kepler...-first-law.svg

    In those elliptical orbits, there is no zig zag orbiting path. (Only a clear elliptical cycle)

    In all the examples which you have offered, there is also No zig zag.
    There is a constant drift (so it set a motion in 3D) but it is not Zig Zag or wobbling.

    The only way to get this zig zag is by setting two layers of orbit.
    For example:
    http://scienceline.ucsb.edu/getkey.php?key=4731
    "Well the moon like the earth revolves around the Sun. If you were far away you would see that as the moon goes around the sun it wobbles a little bit because it also revolves around the Earth."

    Hence, the zig Zag (or wobbles) is feasible by setting two layers of orbital cycle.

    It is so simple.
    Why do we need to make it complicate?
    Why do we insist to fit it in one orbit cycle?
    Last edited by Dave Lee; 2018-Jan-10 at 08:38 PM.

  5. #125
    Join Date
    Sep 2015
    Posts
    302
    I have found a very interesting article

    http://www.slate.com/blogs/bad_astro..._is_wrong.html

    "This is actually pretty cool: If you are slightly above the disk you feel an overall pull down, toward the disk. Imagine the disk is just a huge slab of matter, and the Sun is above it. The gravity of the disk would make the Sun plunge down into it. Since stars are so far apart, the Sun would go right through the disk and out the bottom. But then the disk would be pulling it up, once again toward the disk. The Sun would slow, stop, and reverse course, plummeting into the disk once again. It gets about 200 or so light years from the midplane of the galactic disk every time its bobs; the disk is 1000 light years thick, though, so we always stay well inside it. But these oscillations would go on forever, the Sun moving up and down like a cork in the ocean."

    However, the following message is THE most important one.
    It is stated:

    "Since the Sun is also orbiting the galaxy, the combined motion makes that lovely waving pattern, up-and-down as it goes around, like a horse on a carousel."

    So, it is clear to that person that two activities is needed.

    As it is stated: "Since the Sun is also orbiting the galaxy" and there is a need to "combined motion"

    Therefore - it is a solid prove that two activities is needed for that Zig Zag orbiting!!!

    So, one orbital path is needed to orbit the galaxy, and there is other motion to set the wobbling activity.
    However, this wobbling is just another simple orbit.
    I really can't understand why they try to sell us that kind of story about pull down or pull up, while Newton gravity of the second orbital cycle can do it so easy.
    Last edited by Dave Lee; 2018-Jan-10 at 09:00 PM.

  6. #126
    Join Date
    Oct 2009
    Location
    a long way away
    Posts
    10,030
    Quote Originally Posted by Dave Lee View Post
    There is no Zig zag orbiting by Newton or Kepler.
    1. Kepler's laws don't apply.

    2. The "zig zag" orbit is calculated using Newton's laws.

    So please stop repeating your blatantly false assertions.

    It is so simple.
    Why do we need to make it complicate?
    Why do we insist to fit it in one orbit cycle?
    Why don't you understand the physics involved?

  7. #127
    Join Date
    Oct 2009
    Location
    a long way away
    Posts
    10,030
    Quote Originally Posted by Dave Lee View Post
    I have found a very interesting article
    Which is telling you the same thing that people here are.

    However, this wobbling is just another simple orbit.
    And I really though you had got it.

    It is not an orbit, it is closer to a pendulum. Can you describe the motion of a pendulum as an orbit?

    I really can't understand why they try to sell us that kind of story about pull down or pull up
    Because that is what the physics says. To quote the article:
    If you are slightly above the disk you feel an overall pull down, toward the disk. Imagine the disk is just a huge slab of matter, and the Sun is above it. The gravity of the disk would make the Sun plunge down into it. Since stars are so far apart, the Sun would go right through the disk and out the bottom. But then the disk would be pulling it up, once again toward the disk. The Sun would slow, stop, and reverse course, plummeting into the disk once again.
    That is based on Newton's laws, not wishful thinking.

  8. #128
    Join Date
    Sep 2003
    Location
    The beautiful north coast (Ohio)
    Posts
    46,632
    Quote Originally Posted by Dave Lee View Post
    Thanks for the questions.
    However, the following one is THE most important (as I see it).
    Dave Lee

    This thread is rapidly going nowhere.

    You need to start directly answering all the questions that have been put to you, not just the ones you think are interesting. You need to address all of them systematically.

    And you need to start offering a very clear explanation of what EXACTLY you are claiming and you need to present some evidence for those claims. Evidence does not consist of repeated, incorrect assertions by you, nor links to imprecise drawings or vague articles by others.

    You need to start doing this immediately, or this thread will be closed.
    At night the stars put on a show for free (Carole King)

    All moderation in purple - The rules

  9. #129
    Join Date
    May 2005
    Posts
    7,764
    Quote Originally Posted by Dave Lee View Post
    I have found a very interesting article
    That's Phil Plait, the old Bad Astronmer, you quoted his article extensively in the 34th post of this thread.
    http://www.slate.com/blogs/bad_astro..._is_wrong.html

    "This is actually pretty cool: If you are slightly above the disk you feel an overall pull down, toward the disk. Imagine the disk is just a huge slab of matter, and the Sun is above it. The gravity of the disk would make the Sun plunge down into it. Since stars are so far apart, the Sun would go right through the disk and out the bottom. But then the disk would be pulling it up, once again toward the disk. The Sun would slow, stop, and reverse course, plummeting into the disk once again. It gets about 200 or so light years from the midplane of the galactic disk every time its bobs; the disk is 1000 light years thick, though, so we always stay well inside it. But these oscillations would go on forever, the Sun moving up and down like a cork in the ocean."

    However, the following message is THE most important one.
    It is stated:

    "Since the Sun is also orbiting the galaxy, the combined motion makes that lovely waving pattern, up-and-down as it goes around, like a horse on a carousel."

    So, it is clear to that person that two activities is needed.

    As it is stated: "Since the Sun is also orbiting the galaxy" and there is a need to "combined motion"

    Therefore - it is a solid prove that two activities is needed for that Zig Zag orbiting!!!

    So, one orbital path is needed to orbit the galaxy, and there is other motion to set the wobbling activity.
    However, this wobbling is just another simple orbit.
    I really can't understand why they try to sell us that kind of story about pull down or pull up, while Newton gravity of the second orbital cycle can do it so easy.
    The pull up and pull down is Newtonian gravity at work.

    Your previous post:
    Quote Originally Posted by Dave Lee View Post
    O.K.

    As you ask for mathematical language, let me focus on the Sun motion in the galaxy:

    http://www.slate.com/blogs/bad_astro..._is_wrong.html

    It is stated:

    "A far more correct (though exaggerrated vertically for clarity) depiction of the Sun's motion around the Milky Way galaxy has it bobbing up and down every 64 million years due to the gravity of the galactic disk."

    So, the Sun is bobbing up and down from the galactic disk - every 64 Million years.
    Our scientists claim that it is due to the gravity of the galactic disc.

    The explanation is as follow:

    "That’s because of the way the gravity in the disk works. This is actually pretty cool: If you are slightly above the disk you feel an overall pull down, toward the disk. Imagine the disk is just a huge slab of matter, and the Sun is above it. The gravity of the disk would make the Sun plunge down into it. Since stars are so far apart, the Sun would go right through the disk and out the bottom. But then the disk would be pulling it up, once again toward the disk. The Sun would slow, stop, and reverse course, plummeting into the disk once again. It gets about 200 or so light years from the midplane of the galactic disk every time its bobs"

    Is it correct?
    I don't think so.
    It is mostly correct, as you seem to be coming around to.

  10. #130
    Join Date
    Aug 2008
    Location
    Wellington, New Zealand
    Posts
    3,580
    Quote Originally Posted by Dave Lee View Post
    Thanks for the questions. ...
    Which were not answered by repeating your unsupported assertion, ignoring them or irrelevant graphics and links.
    IF01: What does the Sun orbit around in your ATM idea (show your work)?
    IF02a: Are you persisting in the idea that it is physically impossible for the Sun to "bob" up and down during its orbit around the center of the galaxy.
    If yes:
    IF03a: Define what you mean by "by only one orbital Cycle".
    IF03b: Show that a "Zig Zag orbiting path in three dimensions by only one orbital Cycle" is physically impossible.

    If you cannot define "by only one orbital Cycle" then I have to assume that you mean what you wrote. Thus:
    The Sun does not orbit around the galaxy one and only one time (only one orbital cycle). It has made many orbits. There need not be a integer number of "bobs" during one orbital cycle.
    Last edited by Reality Check; 2018-Jan-10 at 09:36 PM.

  11. #131
    Join Date
    Aug 2008
    Location
    Wellington, New Zealand
    Posts
    3,580
    Quote Originally Posted by Dave Lee View Post
    I have found a very interesting article...
    You quote an article supporting exactly what we have been telling you.
    http://www.slate.com/blogs/bad_astro..._is_wrong.html
    This is actually pretty cool: If you are slightly above the disk you feel an overall pull down, toward the disk. Imagine the disk is just a huge slab of matter, and the Sun is above it. The gravity of the disk would make the Sun plunge down into it. Since stars are so far apart, the Sun would go right through the disk and out the bottom. But then the disk would be pulling it up, once again toward the disk. The Sun would slow, stop, and reverse course, plummeting into the disk once again. It gets about 200 or so light years from the midplane of the galactic disk every time its bobs; the disk is 1000 light years thick, though, so we always stay well inside it. But these oscillations would go on forever, the Sun moving up and down like a cork in the ocean.
    It is the combination of this up and down motion and the orbit of the Sun around the center of the galaxy that produces a three dimensional, wave like orbit of the Sun in the galaxy. This is what we have been trying to tell you for days now.

    The oscillations ("wobbles") are not an orbit. The English and scientific meaning of oscillation is a motion back and forth along a line. The English and scientific meaning of orbit is a motion around a point.
    There is a similar hypothetical example: Construct a frictionless, vacuum tube from one side of the Earth to the other side through the center. Let a mass go at one entrance. The mass will drop downward gaining velocity until it has a maximum velocity at the center. It will then rise up to the other entrance, losing velocity. At the other entrance the mass will have zero velocity and be pulled down again. The mass will oscillate back and forth forever. Add the orbit of the Earth and we have a three dimensional, wave like orbit as above.
    Last edited by Reality Check; 2018-Jan-10 at 09:53 PM.

  12. #132
    Join Date
    Jun 2007
    Posts
    5,508
    Quote Originally Posted by Dave Lee View Post
    I really can't understand why they try to sell us that kind of story about pull down or pull up, while Newton gravity of the second orbital cycle can do it so easy.
    Because scientists like their models of the universe to have something to do with reality. Your "second orbital cycle" has nothing to do with physics. It is not based on Newtonian gravity, which has nothing at all to do with "cycles" of any sort, and is incapable of dealing with the complexity of real world orbital trajectories, which Newtonian gravity has no trouble with. You have simply resurrected cycles and epicycles, completely unnecessarily and with no physical basis.

  13. #133
    Join Date
    Sep 2015
    Posts
    302
    Quote Originally Posted by grant hutchison View Post
    Really simple argument:
    Imagine a thick disc of uniform density.
    Place an object in the geometrical centre of this disc. The object is surrounded by an equal mass distribution in all directions, so the net gravitational force on it must be zero.
    Move the object to the surface of the disc, again centred. The object now has all the mass distributed below it, and none above, so the net gravitational force must be non-zero, and directed towards the disc.

    Therefore, if we move the object from the geometrical centre of the disc to the centre of its surface, the gravitational force it experiences must increase from zero to some non-zero value.

    Although the sun is not at the centre of the galaxy, the same argument applies - the gravitational force now resolves into a radial force (which keeps the sun in orbit around the galaxy) and a force normal to the plane of the galaxy, which is zero when the sun is in the midplane, and which increases as it moves away from the midplane, pulling the sun back towards the midplane.

    Grant Hutchison
    Thanks again for your explanation.

    My feedback is as follow:

    A. "Place an object in the geometrical centre of this disc. The object is surrounded by an equal mass distribution in all directions, so the net gravitational force on it must be zero."
    So, if the Star is located at the galactic disc plane the net gravitational force is Zero. I assume that it represents the steady state situation which the star aspires to be. So, any star in the
    Galaxy will try to get to this steady state place.

    B. "Move the object to the surface of the disc, again centred. The object now has all the mass distributed below it, and none above, so the net gravitational force must be non-zero, and directed towards the disc. Therefore, if we move the object from the geometrical centre of the disc to the centre of its surface, the gravitational force it experiences must increase from zero to some non-zero value."
    I see it as spring power or some sort of Trampoline. If we push the star above the galactic disc, there will be an increased power to pull it down. If we push the star below the galactic disk, there will be an increased power to pull it up.

    I hope that I understand it correctly, therefore:

    1. It is clear that at some point of time the Sun (and any other star in the galaxy) will just rest at the Galactic disc without any interruption, (No wobbling and No Zig Zag activity). So, it is expected that many stars in the galaxy will be located at the disc plane without any wobbling activity. If I understand it correctly, all the stars in the galaxy are wobbling. Therefore, I see a contradiction to the idea of zero gravity power on the galactic plane.
    2. I wonder what kind of power was needed to push the star from the center of the galactic Disc and what was the source for this power that had lifted the Sun above or below the disc. I couldn't find it. If there is no clear external source power to start the wobbling, than stars shouldn't wobble.
    3. I also wonder how many wobbling cycles is needed for the sun (or any other star) to get back to its steady state place at the galactic disc, (Assuming that the interruption of the external power has gone). It is expected that at some point of time the stars would get to that zero power location.
    4. If we start by pushing the Sun to 1 LY (for example) above the Galactic Disc, I would expect that after crossing the galactic disc it will get to 1 LY below the galactic disc. However, I have found, that the center of the Sun' wobbling wave is not located at the galactic disc, but above it. This proves that our idea about the zero gravity power at the galactic disc is incorrect.

    C. With Regards to the Galactic disc:
    "Imagine a thick disc of uniform density."
    5. The thickness of the disc is not uniform. Closer to the Center it is quite thick, further from the center, it is very thin.
    If the gravity power on the galactic disc was zero as stated, it was expected that all the stars will try to be at the Galactic Disc Plane or around it as they set the wobble activity.
    Therefore, it is expected that the thickness of the galactic disc should be uniform at any distance from the center. (Even if the stars density closer to the center of the galaxy might be higher).
    6. Wobbling at the Thick aria of the galactic Disc - It is expected that any wobbling activity of any star, would cross the galactic disc. Therefore, At least some of the stars must set a very high wobbling activity. (From the upper most of the disc to the lower most of the disc). If they do not do so, than there is a problem in this theory.
    7. Technically, if we can find even one star which is located above or below the galactic disc without crossing it, than it is a solid prove that the idea of zero power at the galactic disc isn't realistic
    Last edited by Dave Lee; 2018-Jan-11 at 05:07 PM.

  14. #134
    Join Date
    Jul 2005
    Posts
    15,038
    Quote Originally Posted by Dave Lee View Post
    A. "Place an object in the geometrical centre of this disc. The object is surrounded by an equal mass distribution in all directions, so the net gravitational force on it must be zero."
    So, if the Star is located at the galactic disc plane the net gravitational force is Zero. I assume that it represents the steady state situation which the star aspires to be. So, any star in the
    Galaxy will try to get to this steady state place.
    Absolutely not. There is no force to keep an object in that plane, so objects will naturally oscillate back and forth through the plane.

    Quote Originally Posted by Dave Lee View Post
    B. "Move the object to the surface of the disc, again centred. The object now has all the mass distributed below it, and none above, so the net gravitational force must be non-zero, and directed towards the disc. Therefore, if we move the object from the geometrical centre of the disc to the centre of its surface, the gravitational force it experiences must increase from zero to some non-zero value."
    I see it as spring power or some sort of Trampoline. If we push the star above the galactic disc, there will be an increased power to pull it down. If we push the star below the galactic disk, there will be an increased power to pull it up.
    Yes. And no force to keep it in the plane. So an endless oscillation. (Sound familiar?)



    Quote Originally Posted by Dave Lee View Post
    1. It is clear that at some point of time the Sun (and any other star in the galaxy) will just rest at the Galactic disc without any interruption, (No wobbling and No Zig Zag activity). So, it is expected that many stars in the galaxy will be located at the disc plane without any wobbling activity. If I understand it correctly, all the stars in the galaxy are wobbling. Therefore, I see a contradiction to the idea of zero gravity power on the galactic plane.
    2. I wonder what kind of power was needed to push the star from the center of the galactic Disc and what was the source for this power that had lifted the Sun above or below the disc. I couldn't find it. If there is no clear external source power to start the wobbling, than stars shouldn't wobble.
    3. I also wonder how many wobbling cycles is needed for the sun (or any other star) to get back to its steady state place at the galactic disc, (Assuming that the interruption of the external power has gone). It is expected that at some point of time the stars would get to that zero power location.
    4. If we start by pushing the Sun to 1 LY (for example) above the Galactic Disc, I would expect that after crossing the galactic disc it will get to 1 LY below the galactic disc. However, I have found, that the center of the Sun' wobbling wave is not located at the galactic disc, but above it. This proves that our idea about the zero gravity power at the galactic disc is incorrect.
    No, there is no reason for stuff to collect in the galactic plane. The natural state is for things to oscillate back and forth through the galactic plane, just like the pendulum Strange has been telling you about (and which you really need to consider). With regard to your idea that the "center of the Sun' wobbling wave is not located at the galactic disc, but above it", you're simply being misled by a pretty diagram you've found online, which has several other things wrong with it, too. Just to remind you, once again: the oscillation of the Sun through the galactic plane is not an observation; it is a trajectory derived mathematically from a correct application of Newtonian gravity to a disc.

    Quote Originally Posted by Dave Lee View Post
    C. With Regards to the Galactic disc:
    "Imagine a thick disc of uniform density."
    5. The thickness of the disc is not uniform. Closer to the Center it is quite thick, further from the center, it is very thin.
    Yes, which is why I pointed out that we needed to model the galactic disc as several superimposed discs, reflecting the several populations of stars.
    Quote Originally Posted by Dave Lee View Post
    If the gravity power on the galactic disc was zero as stated, it was expected that all the stars will try to be at the Galactic Disc Plane or around it as they set the wobble activity.
    That is a misunderstanding of how gravity works.
    Quote Originally Posted by Dave Lee View Post
    Therefore, it is expected that the thickness of the galactic disc should be uniform at any distance from the center. (Even if the stars density closer to the center of the galaxy might be higher).
    No. There are several populations of stars in the disc, with several characteristic velocities, which take them varying distances from the galactic plane during their oscillations.
    Quote Originally Posted by Dave Lee View Post
    6. Wobbling at the Thick aria of the galactic Disc - It is expected that any wobbling activity of any star, would cross the galactic disc. Therefore, At least some of the stars must set a very high wobbling activity. (From the upper most of the disc to the lower most of the disc). If they do not do so, than there is a problem in this theory.
    7. Technically, if we can find even one star which is located above or below the galactic disc without crossing it, than it is a solid prove that the idea of zero power at the galactic disc isn't realistic
    Once again, the trajectories are derived from an understanding of gravity, and the measured velocities of stars. We cannot observe the trajectories, because they take place over millions of years.

    Please abandon the idea that these trajectories are observables that must be explained.

    Grant Hutchison

  15. #135
    Join Date
    Mar 2007
    Location
    Falls Church, VA (near Washington, DC)
    Posts
    7,775
    It appears that Dave Lee's thinking is at least in part a throwback to Aristotle, who believed that bodies would come to rest unless forcibly kept in motion. He was not a bad physicist, but he could only test lines of thought on things he could observe on the surface of the Earth and in air, because of technical limitations at the time. The principles which Newton discovered and expanded upon were counterintuitive to Aristotle in his time, as is much of what has become second nature to us in the practice of physics.

  16. #136
    Join Date
    Jun 2007
    Posts
    5,508
    Quote Originally Posted by Hornblower View Post
    It appears that Dave Lee's thinking is at least in part a throwback to Aristotle, who believed that bodies would come to rest unless forcibly kept in motion. He was not a bad physicist, but he could only test lines of thought on things he could observe on the surface of the Earth and in air, because of technical limitations at the time. The principles which Newton discovered and expanded upon were counterintuitive to Aristotle in his time, as is much of what has become second nature to us in the practice of physics.
    I had the same thought. The insistence on some "steady state" and fixation on simple Keplerian orbits sounds like Aristotle's concept of things trying to follow some sort of "natural motion", with applied forces only causing temporary variations from this.

    The confusion extends to having a poor concept of the physical quantities of motion: the concepts of force, velocity, momentum, and energy were very poorly defined before Newton. "Power" is a rate of change in energy over time. Gravitation is not measured in units of power, it is treated either as an acceleration or a force, the two being related by the mass of the object being accelerated by the force. All these terms have specific meanings, and the way Dave Lee uses them shows a lack of understanding.

    Dave Lee, direct question time:

    All questions assume Newtonian approximations.

    1: Do you agree that gravitational force is described by the equations here? https://en.wikipedia.org/wiki/N-body...al_formulation

    2: Do you agree that objects move according to Newton's laws, described here? https://en.wikipedia.org/wiki/Newton%27s_laws_of_motion

    3: How are the above two consistent with your assumption that stars or other massive bodies "aspire" to particular locations or motions, rather than simply moving under the influence of gravity according to the laws of motion?

  17. #137
    Join Date
    Jun 2005
    Posts
    12,548
    Quote Originally Posted by Dave Lee View Post

    1. It is clear that at some point of time the Sun (and any other star in the galaxy) will just rest at the Galactic disc without any interruption, (No wobbling and No Zig Zag activity).
    As others pointed out, this is a misconception. I surmise that you are starting from the idea of a bouncing ball, which eventually stops bouncing. But you probably have heard about the conservation of energy, so in a sense the ball should keep bouncing forever. The reason it stops bouncing is that the energy is transferred to the surface (for example, you can hear a sound, which comes from vibrations caused by the impact), and to the air because of friction. In a perfect vacuum with a perfectly elastic collision, the ball would keep bouncing forever. The stars are essentially in a vacuum, so they will keep oscillating nearly forever.
    As above, so below

  18. #138
    Join Date
    Sep 2015
    Posts
    302
    Quote Originally Posted by grant hutchison View Post
    With regard to your idea that the "center of the Sun' wobbling wave is not located at the galactic disc, but above it", you're simply being misled by a pretty diagram you've found online, which has several other things wrong with it, too. Just to remind you, once again: the oscillation of the Sun through the galactic plane is not an observation; it is a trajectory derived mathematically from a correct application of Newtonian gravity to a disc.

    Grant Hutchison
    Thanks for this answer.
    It is a proof that you agree that there are contradictions between the diagram and the theory. (Otherwise, you won't offer this answer).
    So, our scientists set this diagram by monitoring the Sun movement and with massive calculations.
    In order to explain that orbital outcome, another group had offered a theory.
    I have proved that there are contradictions between the two.
    If you think that there is an error in the calculation - than it is expected to fix it.
    Otherwise, you have to fix the theory.

  19. #139
    Join Date
    Sep 2015
    Posts
    302
    Quote Originally Posted by cjameshuff View Post

    Dave Lee, direct question time:

    All questions assume Newtonian approximations.

    1: Do you agree that gravitational force is described by the equations here? https://en.wikipedia.org/wiki/N-body...al_formulation

    2: Do you agree that objects move according to Newton's laws, described here? https://en.wikipedia.org/wiki/Newton%27s_laws_of_motion

    Yes, Sure.
    Fully agree.

    Quote Originally Posted by cjameshuff View Post

    3: How are the above two consistent with your assumption that stars or other massive bodies "aspire" to particular locations or motions, rather than simply moving under the influence of gravity according to the laws of motion?
    The answer is simple:
    In real kepler and Newton law there is no change in gravity power during the orbital path of the object!!!
    So, at any given moment the object gets the same power. (Just the same constant gravity power).

    Based on that theory, at any given moment, the object gets different gravity force.
    If it is at its pick, the gravity force is maximal, if it is in the galactic disc, the gravity force is Zero.
    Any object will try to stay at a place without external power.
    Same issue with tennis ball.
    If you set it above the ground, its potential power is maximal, as it bounce back from the ground, it decreases its velocity till final steady state.

    There is another issue:
    Gravity works vertically.

    Please see the following message:

    Quote Originally Posted by grant hutchison View Post
    So as the sun moves around the galaxy, it also goes up, stops moving upwards, and then comes down again.
    And as the ball in Jens's example moves from thrower to catcher, it also goes up, stops moving upwards, and then comes down again.
    Direct question: Do you agree with that?

    Grant Hutchison
    So, if the Sun stops at the top pick, it must come vertically to the galactic center.
    This isn't the case with our Sun.
    So, there is one more contradiction.

    You can fix the diagram or fix the theory.
    But please you shouldn't accept them both.
    Last edited by Dave Lee; 2018-Jan-12 at 04:58 AM.

  20. #140
    Join Date
    Jun 2005
    Posts
    12,548
    Quote Originally Posted by Dave Lee View Post
    Same issue with tennis ball.
    If you set it above the ground, its potential kinetic power is maximal, as it bounce back from the ground, it decreases its velocity till final steady state.
    I think perhaps you haven't read my post 137 yet.
    As above, so below

  21. #141
    Join Date
    Sep 2015
    Posts
    302
    Quote Originally Posted by Jens View Post
    As others pointed out, this is a misconception. I surmise that you are starting from the idea of a bouncing ball, which eventually stops bouncing. But you probably have heard about the conservation of energy, so in a sense the ball should keep bouncing forever. The reason it stops bouncing is that the energy is transferred to the surface (for example, you can hear a sound, which comes from vibrations caused by the impact), and to the air because of friction. In a perfect vacuum with a perfectly elastic collision, the ball would keep bouncing forever. The stars are essentially in a vacuum, so they will keep oscillating nearly forever.

    O.K.
    Let's focus on conservation of energy.
    In our real life the conservation of energy is never 100%.
    There is always some minor change.
    In the Earth it might be due to air friction, in the space it might be due to other unknown source of friction.

    We have never found a machine that can work at 100% conservation of energy.
    It is clear that if you change energy you must lose something over time.

    Therefore, you have stated:
    "so they will keep oscillating nearly forever"

    This is not the case in a constant energy.
    You do not change energy and there is no Energy oscillation. Therefore you are not losing energy due to the oscilation.
    Therefore, In a real constant gravity power based Keler and Newton you can keep it forever.
    Last edited by Dave Lee; 2018-Jan-12 at 05:32 AM.

  22. #142
    Join Date
    Oct 2009
    Posts
    1,620
    Quote Originally Posted by Dave Lee View Post
    O.K.
    Let's focus on conservation of energy.
    Ok, let's.

    In our real life the conservation of energy is never 100%.
    In our real life 100% of the energy is always conserved.

    There is always some minor change.
    Change does not imply a failure of energy conservation. Energy changes forms all the time, but when it's all added up, there is never "missing" energy or a surplus. It's 100%. The great conservation laws are tied in a fundamental way to various symmetries, as shown by Emmy Noether a century ago.

  23. #143
    Join Date
    Jun 2007
    Posts
    5,508
    Quote Originally Posted by Dave Lee View Post
    Yes, Sure.
    Fully agree.
    Apparently this is not true.


    Quote Originally Posted by Dave Lee View Post
    The answer is simple:
    In real kepler and Newton law there is no change in gravity power during the orbital path of the object!!!
    So, at any given moment the object will get the same power. (Just the same constant gravity power).
    Simple answers are not necessarily correct. The law of gravity you just said you agreed with is an inverse square law.
    What is the force of gravity exerted by the sun on Mercury at aphelion?
    What is the force of gravity exerted by the sun on Mercury at perihelion?
    What units are the above measured in?


    Quote Originally Posted by Dave Lee View Post
    Based on that theory, at any given moment, the object gets different gravity force.
    If it is at its pick, the gravity force is maximal, if it is in the galactic disc, the gravity force is Zero.
    Any object will try to stay at a place without external power.
    Same issue with tennis ball.
    If you set it above the ground, its potential kinetic power is maximal, as it bounce back from the ground, it decreases its velocity till final steady state.
    It's clear you have no conception of what Newton's laws of motion actually are.
    Cite a scientific definition of "potential kinetic power". What SI unit is it measured in?

  24. #144
    Join Date
    Sep 2015
    Posts
    302
    OK

    I accept your message with regards to the oscillation in the gravity.

    However, would you kindly answer the contradictions between the diagram and the theory?
    Especially with regards to the idea that the center of the sine wave is not located at the galactic disc and the sun movement is not vertically to the disc.

  25. #145
    Join Date
    May 2005
    Posts
    7,764
    Quote Originally Posted by Dave Lee View Post
    Thanks for this answer.
    It is a proof that you agree that there are contradictions between the diagram and the theory. (Otherwise, you won't offer this answer).
    Which diagram? This one?

    https://www.physicsforums.com/thread...ky-way.888643/

    I've already told you that that diagram was made by someone who didn't know what they were doing. The diagram is wrong.
    So, our scientists set this diagram by monitoring the Sun movement and with massive calculations.
    In order to explain that orbital outcome, another group had offered a theory.
    I have proved that there are contradictions between the two.
    If you think that there is an error in the calculation - than it is expected to fix it.
    Otherwise, you have to fix the theory.

  26. #146
    Join Date
    Sep 2015
    Posts
    302
    Quote Originally Posted by grapes View Post
    Which diagram? This one?

    https://www.physicsforums.com/thread...ky-way.888643/

    I've already told you that that diagram was made by someone who didn't know what they were doing. The diagram is wrong.
    So why we don't offer a correction?

    Please also see the following one:

    https://www.quora.com/Why-do-we-see-...Way-vertically

    "This shows you how our solar system's orbital plane is about 60º relative to that of the galaxy's."
    Last edited by Dave Lee; 2018-Jan-12 at 07:54 AM.

  27. #147
    Join Date
    Mar 2003
    Posts
    2,884
    Quote Originally Posted by Dave Lee View Post
    So why we do offer a correction?

    Please also see the following one:

    https://www.quora.com/Why-do-we-see-...Way-vertically

    "This shows you how our solar system's orbital plane is about 60º relative to that of the galaxy's."
    So? Why do you think the angle of the ecliptic plane to the galactic disc has anything to do with the matter under discussion?

    You do also realise the diagram you refer to is not even remotely to scale? The diameter of the solar system is measured in light hours - the thickness of the disc is roughly 1000 light years. Our solar system is comfortably embedded inside the disc, even at the peaks & troughs of its oscillations.

  28. #148
    Join Date
    Sep 2015
    Posts
    302
    Quote Originally Posted by AGN Fuel View Post
    So? Why do you think the angle of the ecliptic plane to the galactic disc has anything to do with the matter under discussion?
    If we claim that the Sun goes up and down with reference to the galactic disc due to the gravity, than it must be vertical to the disc (exactly at 90º).
    This isn't the case.
    So how can we explain this shift?

    If you look carefully, it seems as an orbital path around some center of mass.
    It is not just Up Down movement with a perfect gravity oscillating.

    Do we have also problem with this diagram?
    Last edited by Dave Lee; 2018-Jan-12 at 07:52 AM.

  29. #149
    Join Date
    Mar 2003
    Posts
    2,884
    Quote Originally Posted by Dave Lee View Post
    If we claim that the Sun goes up and down with reference to the galactic disc due to the gravity, than it must be vertical to the disc (exactly at 90º).
    Nonsense. You are confusing the ecliptic plane (the rough plane of the planet's orbit around the sun) with the sun's motion around the Galaxy. There is no obligation for them to be at all aligned.

    This isn't the case.
    So how can we explain this shift?
    There's nothing to explain. You have misinterpreted a simple diagram that is designed to do nothing more than show the angle of the ecliptic plane, to read it as a track of the sun's motion around the Galaxy. It isn't. What's more, I think you think they diagram is a realistic illustration of the sun's orbit, when it's not remotely close.

    If you look carefully, it seems as an orbital path around some center of mass.
    Yes. That would be the sun - given what you are looking at is a diagram of the plane of our solar system.

    Do we have also problem with this diagram?
    One of us does.... It is not showing what you think it is showing.

  30. #150
    Join Date
    Oct 2009
    Location
    a long way away
    Posts
    10,030
    Quote Originally Posted by Dave Lee View Post
    In real kepler and Newton law
    Can you explain why you eep mentioning Kepler?

    There is another issue:
    Gravity works vertically.

    Please see the following message:

    So, if the Sun stops at the top pick, it must come vertically to the galactic center.
    This isn't the case with our Sun.
    So, there is one more contradiction.
    It doesn't fall vertically to the galactic centre because it is in orbit. So it is moving sideways as well as up and down (remember our discussion about vectors and different components of the movement). So it is not like throwing a tennis ball up in the air and watching at fall down again, it is like hitting it across a tennis court. It doesn't reach its highest point and then just drop vertically. It carries on across the court as it falls.

    You can fix the diagram or fix the theory.
    But please you shouldn't accept them both.
    You have already been told that the diagram is very inaccurate in many ways.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •