Recent content by JohnNemo

  1. J

    Fun experiments to disprove Flat Earth

    But if it is close by and you are seeing parallax from a flat Earth, the North Star would not disappear below the horizon as you go over the equator.
  2. J

    "Classical Physics Is Wrong" Fallacy - Comments

    Anyway. I am glad we are now agreed!
  3. J

    "Classical Physics Is Wrong" Fallacy - Comments

    Like a lot of things in this thread it has to be read in context but basically what I was saying was that the fact that Newton's theories (as originally proposed by Newton) make predictions which are approximately accurate only up to a certain limit is a "happenstance". It is not part of the...
  4. J

    "Classical Physics Is Wrong" Fallacy - Comments

    I think you make that point very well here: "Moral of the Story Classical physics WORKS for our ordinary situation, so it HAS to be valid at some level. Classical physics has been shown to be derivable from SR and QM under special conditions that apply to our ordinary situation. Any...
  5. J

    "Classical Physics Is Wrong" Fallacy - Comments

    I agree with everything you say (except your first sentence!) and that is exactly my point. Most of the controversy arises because people are using the phrases “Newtonian Mechanics” and “Classical Physics” with different understood meanings without declaring what definition they are using.
  6. J

    "Classical Physics Is Wrong" Fallacy - Comments

    Newton did not regard his theory as limited to v<<c and did not regard his theory as limited to weak gravity. I’m just querying your use of the words “Newtonian limit”. This is a modern concept, not one that Newton recognised. I think a lot of the controversy about whether Classical physics is...
  7. J

    "Classical Physics Is Wrong" Fallacy - Comments

    I think you are unconsciously using (as many people do) the words “Newtonian limit” to mean the whole of Newton’s theories. But it is only a subset of Newton which approximately corresponds to a subset of relativity. The boundary of the subset of Newton’s theory is a happenstance conditioned by...
  8. J

    "Classical Physics Is Wrong" Fallacy - Comments

    Yes, by mathematically correct I meant approximately correct predictions in terms of *measurement*. Not in the sense of getting your sums right! Measurement is not all of Physics. There are also concepts. Newton’s predictions for the effects of gravity may be approximately correct in terms of...
  9. J

    "Classical Physics Is Wrong" Fallacy - Comments

    It is only *necessary* in the weak sense that you are defining “classical limit” as meaning “that part of Newton’s theory which is approximately mathematically correct”. It is necessary only because of your definitions. Ultimately it is a happenstance.
  10. J

    "Classical Physics Is Wrong" Fallacy - Comments

    Exactly, but I’m not sure this point comes out clearly in your article. To say that 1. Newton was wrong (about a lot of things) is not incompatible with saying that 2. It just so happens that within certain limits (which limits we now are aware of and he wasn’t) parts of his theory are...
  11. J

    "Classical Physics Is Wrong" Fallacy - Comments

    By 'classical limit' do you mean the slow speeds for which we now regard classic physics as providing a good approximation? If so that appears to be a modern definition of 'classical'. Newton, for example, did not regard his theories as so limited.
  12. J

    Fun experiments to disprove Flat Earth

    You could link up with a few other schools at varying distances to the south of you. They don't have to be due south - south west or south east, or a combination, is absolutely fine, so you could choose Florida, then southern Mexico (or Barbados if you want an Anglophone country) etc. Get...
  13. J

    I General Relativity & The Sun: Does it Revolve Around Earth?

    Is the bulge around the Earth’s equator caused by this type of frame dragging effect?
  14. J

    I General Relativity & The Sun: Does it Revolve Around Earth?

    This is where I am having difficulty understanding because you often say (e.g. In #152) that a region of space a long way from the nearest star is flat (because the matter and energy in the universe is spherically symmetrical) but here we appear to have a distortion of spacetime caused by the...
  15. J

    I General Relativity & The Sun: Does it Revolve Around Earth?

    https://en.wikipedia.org/wiki/Frame-dragging#Effects also mentions linear frame dragging. Is this also recognised n GR?
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