Re: [Vo]:Dark matter / galaxy rotation problem approached with simple classical physics
On Wed, Jan 12, 2011 at 11:38 PM, David Jonsson davidjonssonswe...@gmail.com wrote: I have derived an effect which differs from Newton/Kepler orbits but with the wrong sign apparently increasing the problem even more. I would be glad if someone could check the calculations before I take them further. It would also be nice to calculate on some real example. http://djk.se/Dark%20matter%20problem%20approached%20with%20classical%20physics,%20local%20rotation%20increases%20the%20centrifugal%20force%20away%20from%20the%20galaxy%20core.pdf How big is the anomalous acceleration at our solar system? OK, the solar system is an example where the effect is very small and practically negligible. I have been looking for binary stars where the effect might be noticeable and it seems like HM Cancri is such a case http://en.wikipedia.org/wiki/RX_J0806.3%2B1527 Those white dwarfs spin around each other at 500 km/s. I give all the details for the calculation in case anyone wants to check them. With the help of this nice tool http://fuse.pha.jhu.edu/cgi-bin/eqtogal_tool i could calculate the galactic coordinates based on the coordinates in Wikipedia, which gave me Epoch J2000.00 coordinates: 08 06 23.20 + 15 27 30.2 = Galactic coordinates: LII=206.9253 BII= 23.3960 Leading to this distance in lightyears from the galaxy core *cos(((207.3669 - 180) / 360) * 2 * pi) * 16000) + 26000)^2) + ((sin(((207.3669 - 180) / 360) * 2 * pi) * 16000)^2) + ((sin((23.9625 / 360) * 2 * pi) * 16000)^2))^0.5 = 41389.7368 light years **= 12.689869 kpc *Which according to this graph http://en.wikipedia.org/wiki/File:Rotation_curve_(Milky_Way).JPG has about the same orbital speed around the galaxy of 220 km/s as our solar system The equation I derived on the top link says a = (vs^2 + vp^2/2)/r which means centrifugal acceleration depends on both the stars' speed in the orbit around the galactic core vs and the spinning speed around its binary vp. Classical acceleration ac = vs^2/r compared to a is a/ac=(vs^2 + vp^2/2)/r/(vs^2/r) = (vs^2 + vp^2/2)/r/(vs^2/r) = (220^2 + 500^2/2)/220^2 = 3.6 So in this case the gravitational pull has to be 3.6 times higher than even the dark matter addition. I think I add this to the document as a relevant example. What would happen in the case of lack of that strong gravity? David
Re: [Vo]:Dark matter / galaxy rotation problem approached with simple classical physics
On 01/12/2011 08:25 PM, David Jonsson wrote: On Thu, Jan 13, 2011 at 12:00 AM, Mauro Lacy ma...@lacy.com.ar mailto:ma...@lacy.com.ar wrote: On 01/12/2011 07:38 PM, David Jonsson wrote: I have derived an effect which differs from Newton/Kepler orbits but with the wrong sign apparently increasing the problem even more. I would be glad if someone could check the calculations before I take them further. It would also be nice to calculate on some real example. http://djk.se/Dark%20matter%20problem%20approached%20with%20classical%20physics,%20local%20rotation%20increases%20the%20centrifugal%20force%20away%20from%20the%20galaxy%20core.pdf I'll take a look later and comment back. How big is the anomalous acceleration at our solar system? If you're talking about the anomalous acceleration of the solar system around the milky way, you can calculate it using the centripetal acceleration formula. I've calculated it in the past. If the Sun is rotating around the galaxy at 220 km/s, and the distance to the center of the Milky Way is ~ 26000 light years, and assuming we're orbiting the galaxy in a circle(which sounds like a good approximation) the Sun must be subjected to a centripetal acceleration ac = v^2/r ~= 2 x 10^-10 m/s^2 Right, and how big is the mass of the galaxy inside the orbit of the solar system. I also need that to determine the error. 200 billion suns seems to be good estimate of the visible matter in the galaxy. From http://hypertextbook.com/facts/2000/AlinaVayntrub.shtml Considering dark matter, total mass could be 9 or 10 times that number. Let's calculate the acceleration produced by 200 million suns. This is doomed to fail because, as we know, galaxies don't obey Newton's gravitational law, but just to have an idea: a= Fg/msun = G msun*2*10^11/(26000 * 9.4607305e+15)^2 = 4.3882998825*10^-10 m/s^2 Which is two times the centripetal acceleration... if we suppose that the central bulge contains half the visible mass, the standard calculation will coincide with the observed values for our Sun. But it will fail for stars farther from the center, which are also moving at 250 km/s. In the wikipedia entry https://secure.wikimedia.org/wikipedia/en/wiki/Milky_Way you can see the expected vs. observed galactic rotation curves https://secure.wikimedia.org/wikipedia/en/wiki/File:Rotation_curve_%28Milky_Way%29.JPG And they inf fact coincide in the case of our Sun. Anyways, any effect smaller than, let's say, 2*10^-11 m/s^2, can be safely ignored. Regards, Mauro I calculated the anomalous effect from my paper and the acceleration was on the order of 10^-26. Apparently too weak and in the wrong direction, or a mistaken calculation. You might be interested in a thread in physics forums called solar system motions (http://www.physicsforums.com/showthread.php?t=383916) where I discuss the subject with some members. The thread called Alternative theories being tested by Gravity probe B (http://www.physicsforums.com/showthread.php?t=104694) from which the previous thread was split off, is interesting also. Hopefully I can check later. Regards, David
Re: [Vo]:Dark matter / galaxy rotation problem approached with simple classical physics
In reply to Mauro Lacy's message of Thu, 13 Jan 2011 09:23:01 -0300: Hi, [snip] Let's calculate the acceleration produced by 200 million suns. This is doomed to fail because, as we know, galaxies don't obey Newton's gravitational law, but just to have an idea: a= Fg/msun = G msun*2*10^11/(26000 * 9.4607305e+15)^2 = 4.3882998825*10^-10 m/s^2 Which is two times the centripetal acceleration... if we suppose that the central bulge contains half the visible mass, the standard calculation will coincide with the observed values for our Sun. But it will fail for stars farther from the center, which are also moving at 250 km/s. In the wikipedia entry https://secure.wikimedia.org/wikipedia/en/wiki/Milky_Way you can see the expected vs. observed galactic rotation curves https://secure.wikimedia.org/wikipedia/en/wiki/File:Rotation_curve_%28Milky_Way%29.JPG And they inf fact coincide in the case of our Sun. Anyways, any effect smaller than, let's say, 2*10^-11 m/s^2, can be safely ignored. [snip] I would be interested in a calculation of the strength of the magnetic attraction/repulsion between the galactic magnetic field and the Solar magnetic field, and by how many orders of magnitude it differs. Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/Project.html
Re: [Vo]:Dark matter / galaxy rotation problem approached with simple classical physics
On Thu, Jan 13, 2011 at 9:19 PM, mix...@bigpond.com wrote: In reply to Mauro Lacy's message of Thu, 13 Jan 2011 09:23:01 -0300: Hi, [snip] Let's calculate the acceleration produced by 200 million suns. This is doomed to fail because, as we know, galaxies don't obey Newton's gravitational law, but just to have an idea: a= Fg/msun = G msun*2*10^11/(26000 * 9.4607305e+15)^2 = 4.3882998825*10^-10 m/s^2 Which is two times the centripetal acceleration... if we suppose that the central bulge contains half the visible mass, the standard calculation will coincide with the observed values for our Sun. But it will fail for stars farther from the center, which are also moving at 250 km/s. In the wikipedia entry https://secure.wikimedia.org/wikipedia/en/wiki/Milky_Way you can see the expected vs. observed galactic rotation curves https://secure.wikimedia.org/wikipedia/en/wiki/File:Rotation_curve_%28Milky_Way%29.JPG And they inf fact coincide in the case of our Sun. Anyways, any effect smaller than, let's say, 2*10^-11 m/s^2, can be safely ignored. [snip] I would be interested in a calculation of the strength of the magnetic attraction/repulsion between the galactic magnetic field and the Solar magnetic field, and by how many orders of magnitude it differs. Sounds relevant, but I have nothing to add. David
Re: [Vo]:Dark matter / galaxy rotation problem approached with simple classical physics
On 01/13/2011 05:19 PM, mix...@bigpond.com wrote: In reply to Mauro Lacy's message of Thu, 13 Jan 2011 09:23:01 -0300: Hi, [snip] Let's calculate the acceleration produced by 200 million suns. This is doomed to fail because, as we know, galaxies don't obey Newton's gravitational law, but just to have an idea: a= Fg/msun = G msun*2*10^11/(26000 * 9.4607305e+15)^2 = 4.3882998825*10^-10 m/s^2 Which is two times the centripetal acceleration... if we suppose that the central bulge contains half the visible mass, the standard calculation will coincide with the observed values for our Sun. But it will fail for stars farther from the center, which are also moving at 250 km/s. In the wikipedia entry https://secure.wikimedia.org/wikipedia/en/wiki/Milky_Way you can see the expected vs. observed galactic rotation curves https://secure.wikimedia.org/wikipedia/en/wiki/File:Rotation_curve_%28Milky_Way%29.JPG And they inf fact coincide in the case of our Sun. Anyways, any effect smaller than, let's say, 2*10^-11 m/s^2, can be safely ignored. [snip] I would be interested in a calculation of the strength of the magnetic attraction/repulsion between the galactic magnetic field and the Solar magnetic field, and by how many orders of magnitude it differs. That can surely be calculated or searched for, and I can attempt it during the weekend. Probably the strengths are too small to produce appreciable accelerations. But what I find most revealing is is the following: I was thinking that the coincidence, in the Sun's case, between the estimated centripetal acceleration(using the centripetal acceleration formula), and the acceleration calculated according to Newton's gravitational formula, is not a mere coincidence. Newton's universal gravitational constant is tuned in to our local environment. That is, G is correlating the amount of visible matter(what we ordinarily call mass and has weight) with the (local) strength of the gravitational field. And is afterwards assuming that correlation to be universal. If we lived near or farther the center of the galaxy, our value for G would be different. An elegant answer is that there's no dark matter, but instead something which interacts with and depends partly on normal matter. Gravity is not a field or force produced by matter, but a velocity field interacting with matter. It depends on matter density(matter density partly defines the local velocity inflow(a velocity field like in a fluid, but hyper dimensional)). That velocity field has (or have had in the past) other causes than matter. Looking at the galaxy rotation curves graph (https://secure.wikimedia.org/wikipedia/en/wiki/File:Rotation_curve_%28Milky_Way%29.JPG) it strikes me as evident that the galaxy is rotating /en masse/. If you look at the blue line(i.e. the observed rotational velocities), the velocity can be thought of as being constant near 200 km/s, with the increases corresponding to the zones of the galaxy arms (i.e. where matter density is greater). So, we have a constant rotational velocity for the whole galactic disc(including empty space), with zones of increased velocity related to increased matter density in those areas. That increased matter density is at the same time the result of an increase of flow velocity, and a cause of it, like in the case of a reinforcing dynamical process. This would explain all the gravitational anomalies as divergences from the accepted value of G. This is, divergences from the relationship between ponderable matter, and the local gravitational field strength in each case. Regards, Mauro
[Vo]:Dark matter / galaxy rotation problem approached with simple classical physics
I have derived an effect which differs from Newton/Kepler orbits but with the wrong sign apparently increasing the problem even more. I would be glad if someone could check the calculations before I take them further. It would also be nice to calculate on some real example. http://djk.se/Dark%20matter%20problem%20approached%20with%20classical%20physics,%20local%20rotation%20increases%20the%20centrifugal%20force%20away%20from%20the%20galaxy%20core.pdf How big is the anomalous acceleration at our solar system? David David Jonsson, Sweden, phone callto:+46703000370
Re: [Vo]:Dark matter / galaxy rotation problem approached with simple classical physics
On 01/12/2011 07:38 PM, David Jonsson wrote: I have derived an effect which differs from Newton/Kepler orbits but with the wrong sign apparently increasing the problem even more. I would be glad if someone could check the calculations before I take them further. It would also be nice to calculate on some real example. http://djk.se/Dark%20matter%20problem%20approached%20with%20classical%20physics,%20local%20rotation%20increases%20the%20centrifugal%20force%20away%20from%20the%20galaxy%20core.pdf I'll take a look later and comment back. How big is the anomalous acceleration at our solar system? If you're talking about the anomalous acceleration of the solar system around the milky way, you can calculate it using the centripetal acceleration formula. I've calculated it in the past. If the Sun is rotating around the galaxy at 220 km/s, and the distance to the center of the Milky Way is ~ 26000 light years, and assuming we're orbiting the galaxy in a circle(which sounds like a good approximation) the Sun must be subjected to a centripetal acceleration ac = v^2/r ~= 2 x 10^-10 m/s^2 You might be interested in a thread in physics forums called solar system motions (http://www.physicsforums.com/showthread.php?t=383916) where I discuss the subject with some members. The thread called Alternative theories being tested by Gravity probe B (http://www.physicsforums.com/showthread.php?t=104694) from which the previous thread was split off, is interesting also. Regards, Mauro
Re: [Vo]:Dark matter / galaxy rotation problem approached with simple classical physics
On Thu, Jan 13, 2011 at 12:00 AM, Mauro Lacy ma...@lacy.com.ar wrote: On 01/12/2011 07:38 PM, David Jonsson wrote: I have derived an effect which differs from Newton/Kepler orbits but with the wrong sign apparently increasing the problem even more. I would be glad if someone could check the calculations before I take them further. It would also be nice to calculate on some real example. http://djk.se/Dark%20matter%20problem%20approached%20with%20classical%20physics,%20local%20rotation%20increases%20the%20centrifugal%20force%20away%20from%20the%20galaxy%20core.pdf I'll take a look later and comment back. How big is the anomalous acceleration at our solar system? If you're talking about the anomalous acceleration of the solar system around the milky way, you can calculate it using the centripetal acceleration formula. I've calculated it in the past. If the Sun is rotating around the galaxy at 220 km/s, and the distance to the center of the Milky Way is ~ 26000 light years, and assuming we're orbiting the galaxy in a circle(which sounds like a good approximation) the Sun must be subjected to a centripetal acceleration ac = v^2/r ~= 2 x 10^-10 m/s^2 Right, and how big is the mass of the galaxy inside the orbit of the solar system. I also need that to determine the error. I calculated the anomalous effect from my paper and the acceleration was on the order of 10^-26. Apparently too weak and in the wrong direction, or a mistaken calculation. You might be interested in a thread in physics forums called solar system motions (http://www.physicsforums.com/showthread.php?t=383916) where I discuss the subject with some members. The thread called Alternative theories being tested by Gravity probe B (http://www.physicsforums.com/showthread.php?t=104694) from which the previous thread was split off, is interesting also. Hopefully I can check later. Regards, David
