J.C.MacSwell

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J.C.MacSwell last won the day on November 25 2016

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About J.C.MacSwell

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  1. Gravity. Please knock this down

    In a simple, steady state flow model in 3 dimensions, at a given distance from the centre the flow should be accelerating at 1/2 of what it is at half the distance (inverse relationship...goes up by twice as it moves to half the distance) With gravity the acceleration is 1/4 that of half the distance. (inverse squared relationship...goes up by 4X as it moves to half the distance). So for the acceleration to more than double you need more space accelerating than you have a supply of...
  2. Gravity. Please knock this down

    You are using gravity as an explanation of how it works.But what, in the model, causes both objects to accelerate at 9.81 m/s²? How is the acceleration imparted? They both need 9.81 m/s² but totally different flows to impart it...unless...what? Other than hand wave "works like gravity". (if it's nothing imparted but just "space removal" why more and faster for one object than the other? One would require more of a reduction of space in the same time frame) With your model (steady flow) space is inflowing and accelerating toward the centre. But unless it is expanding as well the acceleration will not follow an inverse square law (the velocity would). Where does the extra space come from to allow it?
  3. Gravity. Please knock this down

    So steady state (not increasing overall, but just as it gets closer).In the funnel analogy, or your hypothesis, if something arrived with the flow from a distance (say dropped from well above the cliff), how would the movement compare to a second particle released at the cliff edge as the first particle arrived? And why?
  4. Gravity. Please knock this down

    So is the flow increasing at 9.81 mps² at that point? The ocean analogy would have increasing flow toward the centre, but constant speed at each point (this is why I assumed some kind of drag was at work)
  5. Gravity. Please knock this down

    Ok. I guess I took your ocean analogy as how it might work. So the inflow of space somehow affects an object in free fall, but there is no resistance otherwise?
  6. Gravity. Please knock this down

    You haven't answered anything with regard to where the analogy clearly breaks down. Try explaining a simple orbit. In Relativity or Newton Gravity it's free fall. In this it is plowing along tangentially against the medium of the flow. Explain why there is no drag in the tangential direction.
  7. Gravity. Please knock this down

    OK. So you are required to resist the flow/gravity to stay stationary on the Earth's surface (presumably electromagnetic forces at play), and there appears to be a radial inverse square law effect, but how is there no drag tangentially, for orbits? Also, what is the inflow velocity of the flow near the Earth's surface that would interact with matter to produce the 9.81 m/s2 acceleration? If something was already free falling at that speed would it then accelerate much less, only to match the inflow velocity gradient?
  8. Gravity. Please knock this down

    Is this a constant flow? That would be consistent with feeling a constant force while resisting gravity at the surface (like my butt in my chair right now), but if something was dropped would it not get up to flow speed and therefore stop accelerating? (even in a vacuum) Or is it constantly accelerating flow, requiring more and more space to ingest, and why is my butt not feeling a constantly increasing pressure?
  9. homework help

    It is an equation
  10. Gravitation constant or not

    For homogenous spheres it makes no difference if integrated over the complete sphere, or simply calculated assuming r is at the centre point. The result is exactly the same, at any distance, whether using the basic formula or doing the calculus. The "inefficiencies" of the mass off the resultant vector line are exactly compensated by the "extra efficiencies" of the mass that is closer than r being a greater effect than the inefficiencies of the mass further away than r. At greater distances these inefficiencies become less significant, but it is not relevant except when non spheres or varying densities are present since they otherwise cancel out at any distance.
  11. Really only enough information to answer "time required to react before getting eaten"
  12. Not sure what you mean exactly. What was your result?
  13. does it seem reasonable? If that is the final velocity the average would be half that...around 35m/s...and it would have taken about a seventh of a second to get to 70.71m/s You might want to double check the decimal place of your result...
  14. It can effect the amount of dark matter required but obviously not enough to try to explain it otherwise. My main point was that much of the data is less accurate generally than implied by the error ranges given. Much of it for reasons unique to Cosmology.
  15. Assuming I'm thinking it through correctly: Not for doppler shift measurements, no (Hubble effects aside). Wouldn't it exacerbate a problem if it did, rather than cancel? Allowing for Hubble at greater distances would not cancel either. If say you overestimated the distances and you then overestimate the speeds, these both lead to looking for more dark matter. You should however get some cancelling from overestimating mass (thus looking for less dark matter) (by radial velocity here you aren't referring to radial velocities within the galaxy, are you, but radial velocities wrt Earth used to calculate the tangential velocities at radial points, thus rotation curves, of the distant galaxy? )