Tutorial: Shaping the Universe, Gravity and the four forces of nature;.

Discussion in 'Astronomy, Exobiology, & Cosmology' started by paddoboy, May 31, 2020.

  1. Q-reeus Banned Valued Senior Member

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    The latter as a measure of acceleration (not speed) cannot in any sense square with the former which is speed = |velocity|. Apples. Oranges. Basic dimensional analysis.
     
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  3. exchemist Valued Senior Member

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    Well it is continually accelerating, but indeed in an elliptical path the rate of acceleration towards the focus varies. In my understanding "continually" means without ceasing, but does not necessarily mean at constant rate.

    I don't think there is anything to square between g and the earth's orbital speed. Why would there be any connection?
     
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  5. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

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    Not sure if my misunderstanding means posting at cross purposes

    My understanding continually accelerating means continually increasing speed

    Forget about the other for the moment

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  7. exchemist Valued Senior Member

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    Not with motion in a circle, it doesn't. Acceleration is dv/dt, i.e change of velocity with time. Remember both acceleration and velocity are vectors, so they have both magnitude and direction. For motion in a straight line, acceleration requires an increase in velocity, but for motion in a circle the velocity is continually changing direction, not magnitude. (For motion in an ellipse, there is some of each.)
     
  8. paddoboy Valued Senior Member

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    Ahh c'mon now q-reeus, surely your not offended by the smart arse remark?
    Yep, exactly, and that makes sense to me, rather then listening to your own continual whinging and whining re the validity of GR over many years.
    The river analogy is just that, an analogy, and iirc, all accurately, more or less said the same thing...
     
  9. Q-reeus Banned Valued Senior Member

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    Totally uncalled for and yes obviously offensive. The cure - refrain from such abusive language. Choose to be civil - all the time.
    Here you go again. I point to both my own and others clear identification of at least one inconsistency in GR's foundational principles, and you stoop to calling that 'whinging' and 'whining'. Again - learn to respond civilly and accurately. A really big ask I know.
    No they didn't. At least two others stated outright that space doesn't 'fall' like water flowing in a river/waterfall. And I (and writer of Wikipedia article) have shown where 'dragged spacetime' makes a wrong prediction. The 'ether' of spacetime looks the same in every local coordinate system. Michelson And Morley - late 19th century.
     
  10. paddoboy Valued Senior Member

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    If you say so...I will certainly follow your own generally change from the offensive.
    But you have! ever since you started here and followed me over to that other place.
    I can't really recall exactly, but I was not inferring as flowing like a river in particular...but certainly aligning with the bending/warping/twisting geometry in the presence of mass/energy.
     
  11. paddoboy Valued Senior Member

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    OK, after thinking some, and noting the less offensive nature of the banter between us, on both sides, I apologise. Being the first to break that "truce"?
     
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  12. Q-reeus Banned Valued Senior Member

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    Thank you - apology accepted.
     
  13. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

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    OK that's the part I was missing

    Thanks

    Busy right now with Trusted Assistant

    Will come back when she stops bothering me

    Cheers

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  14. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

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    Never was nothing. Always COULD have been nothing, but NOTHING is a state which didn't happen

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  15. paddoboy Valued Senior Member

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    According to Lawrence Krauss, the quantum foam is the nothing that we, spacetime, and everything arose from.
    Our defining of nothing maybe at fault.
    Nice video.
     
  16. paddoboy Valued Senior Member

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    Point is of course, while all we can do is speculate at that time, that speculative scenario, makes far more sense then any supposed supernatural and/or paranormal myth.
    The greatest question, along of course with the 'are we alone" question, is will we ever have an observable QGT.
     
  17. James R Just this guy, you know? Staff Member

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    The Earth is in free fall towards the Sun.

    There's no link between the free-fall acceleration of objects near the Earth's surface and the speed of Earth around the Sun.

    Does that help?
     
  18. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

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    Thanks but as per below

    sorted as per my response

    But still thanks

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