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  1. nearc

    B Prerequistive for posting in Special and General Relativity

    i am far from an expert in Special and General Relativity, however, my attempts to learn from this forum are hampered by the large volume of posts involving common misconceptions and lack of understanding of the material. while the members of the forums patiently [usually] help our novice and...
  2. nearc

    I Modeling a simple N-body in a hypothetical relativistic dark flow

    Looking for existing examples of or guidance on building computer simulations of simple N-bodies in relativist situations. Of particular interest is the simulation of a planet orbiting a star whilst that trivial solar system is caught in a dark flow of relativist velocity; maybe .8 or .9 C. Not...
  3. nearc

    B History of RA [why is the vernal equinox used?]

    i failed to find the history of RA [right ascension] and why the vernal equinox was picked as the starting point on the web or in the forums here. does anyone know the origins of RA? picking a solstice or equinox is obvious but why the vernal? maybe because spring in the northern hemisphere...
  4. nearc

    I Best way to filter NED redshift data

    i'm using http://ned.ipac.caltech.edu/ui/?q=byparams to extract redshift data. while i'm very happy there is now lots of data available, data requests need to be limited in size or you get an error. i would like to examine the patterns of redshift vs longitude, but that is too much data, i...
  5. nearc

    I Tight grouping of exoplanets 295RA 45dec

    does anyone have any information on why the vast majority of exoplanets are located in one spot? any papers on the topic? the following link does not graph RA vs DEC but instead does something about planet size, if you wish to use it please select RA for the x-axis and DEC for the y-axis, both...
  6. nearc

    Where can I get help with David Bachman's A Geometric Approach to Differential Forms?

    this starts as a calculus question, but springs into where i can get help with david bachman's A GEOMETRIC APPROACH TO DIFFERENTIAL FORMS second edition. looking at paul's notes cheat sheets http://tutorial.math.lamar.edu/cheat_table.aspx we have ## \int \frac{1}{\sqrt{a^{2}-x^{2}}} =...
  7. nearc

    Gravitational equations used in model of orbiting bodies

    In practice I’ve found that a valid gravitational model of orbiting bodies only works when the force is computed with only the other mass and not both masses. Thus, the original equation does not work but the modified one does. Is using one mass ok or am I doing something wrong? thanks. [also...
  8. nearc

    Help building an n-body simulation incorporating the speed of gravity

    I would like some introductory level references for building an n-body gravity simulation. I work for the supercomputer challenge [ http://challenge.nm.org/ ] and I build the teaching models each year we use to train teachers in computer modeling and provide as an example model for the students...
  9. nearc

    Traveling signal paradox

    Traveling signal “paradox” Most relativity paradoxes are not true paradoxes they merely require some clarification about frame of references, stationary observer, etc… I hope some folk could help me clarify my “paradox” or point out where someone as already discussed this concept. We...
  10. nearc

    Juno flyby anomaly

    i did a search for juno flyby here and did not find anything, hence this post: i've not been able to find any info on the juno flyby anomaly. i know there was a hiccup but did we get any data? was the observed anomaly match the predicted anomaly?
  11. nearc

    Finding a new way to calculate one side of a triangle

    hopefully this is the right place for this question, the first part is a trig/geometry question but it is really a integration question: i'm trying to find another way to compute d1 without using law of cosines because i don't know how to integrate (cos a)^.5, if someone knows how to do that...
  12. nearc

    Center of magnetic potential vs center of mass

    first i might be using magnetic potential incorrectly so please be nice when correcting me. i'm attempting to model the behavior of a magnetic compass when it is placed next to a ferrous piece of metal. basically the compass will point to the metal rather than north. my first simplification...
  13. nearc

    Two ships again [lets beat that dead horse]

    Two ships are traveling fairly close together side by side heading the same way on parallel paths near the speed of light [lets say v=.999C]. From the internal frame of reference [people in the ships] they can consider themselves as equivalent to being stationary, however from an external...
  14. nearc

    Gravitational force with 1/r^3

    apologies if this has been covered elsewhere in the forums, but i was unable to find it. i've seen the usual gravitational force equation [i.e. F=gMm/r^2] with essentially r^3 in the bottom. an example of this can be seen in http://www.mathworks.com/moler/exm/chapters/orbits.pdf [Broken] on...
  15. nearc

    Another two ships relativity question

    I wanted to double check my calculations an interpretation of relativity. Thanks in advance. Two identical ships leave the same point at the same time traveling .999C and travel a 100 light years each but leave on paths that are 10 degrees apart. If the passengers where to compare their...
  16. nearc

    Relativistic effects on planetary shear [tidal forces]

    before i ask my question i want to review two points: 1. place a body like a moon or a planet near a black hole, as the body approaches the extreme gravity affects the body deferentially. 2. review the tidal forces on Jupiter's moon Io leading to volcanic/tectonic consequences. now take...
  17. nearc

    Computer simulations of expanding space

    i'm looking for computer simulations of expanding space. i made a couple of very very very simple models and my results were no where near our current model of space. hence, i'm looking for work that has already been done on the subject.
  18. nearc

    What can we say about the composition of the universe shortly after the big bang?

    I've been looking for more information about the state of matter [or soon to be matter] shortly after the big bang. As time progressed after the big bang matter started to develop and it became more and more complex and massive [for the most part], we had quarks then protons then neutrons then...
  19. nearc

    Simple relativity question [two ships]

    two identical ships launch on parallel paths r distance apart. the are completely alone [nothing to affect them gravitationally [but themselves]]. once they reach some velocity v [they both reach the same velocity at the same time [everything is identical]] they turn off their engines and...
  20. nearc

    Questions about gravity at relativistic velocities

    The ‘speed’ of gravity, like everything else, is also limited to the speed of light. So if two bodies [with mass] are traveling in the same direction with one trailing directly behind the other by some distance and both bodies are traveling at .999 C how does the gravity work between them? For...
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