What really is a continuous symmetry?

Discussion in 'Physics & Math' started by arfa brane, Oct 27, 2020.

  1. Michael 345 New year. PRESENT is 71 years old Valued Senior Member

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    Ummmmm

    And a list of properties?

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  3. arfa brane call me arf Valued Senior Member

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    I'm leaning towards you not understanding what a property is, or maybe you're trolling.

    I've mentioned two properties of time. That time is continuous, and so is its motion or rate of flow, means it can only go one way, because if it didn't it would be neither continuous, nor constant. Now would it?
     
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  5. Michael 345 New year. PRESENT is 71 years old Valued Senior Member

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    In science, property means a characteristic or trait that you can use to describe matter by observation, measurement, or combination.

    https://study.com/academy/answer/wh...ns a,observation, measurement, or combination.

    So you contend "continuous" and ? , sorry cannot find the second property you claim is present

    Care to enlighten me?

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  7. QuarkHead Remedial Math Student Valued Senior Member

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    You see arfa, either you are contradicting yourself, or you have no idea what you are talking about.

    Early on in this thread - your thread - you suggested there was a Lie group that described time symmetry. But a group - any group, Lie or otherwise - has an inverse. It wouldn't be a group otherwise "now would it?"

    Now you imply here there is no inverse, therefore no continuous symmetry group (at least by my logic).

    Which is it?
     
  8. arfa brane call me arf Valued Senior Member

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    I'm not contradicting anything.
    I said that time is continuous, which means 'motion' in the one dimension it 'has' or 'is', means one and only one direction can be possible, without violating the locally observed linear flow rate.

    Which is to say, motion of a point along a time 'axis' breaks a symmetry. There are no 'time laws' in physics that say why time is like this, or why anything would be different (apart from the discontinuities). if time could flow into the past.
     
    Last edited: Oct 30, 2020
  9. arfa brane call me arf Valued Senior Member

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    No, I said all the continuous symmetry groups are Lie groups. I said time is continuous; topologically a 1-manifold, with a translation invariant.

    I'd like to call this invariant a "clock symmetry". Translating into the past or future of any clock should not change the rate the clock 'ticks', locally.
    Or in a universal context, since time began it has 'flowed' at the same rate and the speed of light has stayed invariant, therefore the entire history of the universe has translational time symmetry (any clock we can construct would work the same billions of years ago as today).
     
    Last edited: Oct 30, 2020
  10. Write4U Valued Senior Member

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    The Bohmian "Wholeness"......

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    Question; Why is it necessary for Time to exists before there is need for Time as a chronolgy and duration of existence in some expressed physical form?
     
    Last edited: Oct 31, 2020
  11. arfa brane call me arf Valued Senior Member

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    Time translation leaves clocks, hence units of time like seconds or years, invariant. That means translation is an identity operation on clocks/intervals of time.

    Like a translation in the plane leaves an object with the same orientation (modulo any orientation-preserving symmetries). Translate a letter like B, and it still looks like B, etc.
     
  12. Michael 345 New year. PRESENT is 71 years old Valued Senior Member

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  13. Write4U Valued Senior Member

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    Suppose there is no clock? The clock has to exist for it to create a durable continuous chronology of its ticking, no?
     
  14. arfa brane call me arf Valued Senior Member

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    Then there are no intervals of time and no constant speed of light. For one.

    In this universe there are clocks and intervals of time. What do you think made humans use lunar calendars? Is the orbit of the moon around earth a natural timekeeping system, perhaps?
     
    Last edited: Oct 31, 2020
  15. arfa brane call me arf Valued Senior Member

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    The point you're making here is that a unit of time is an arbitrary, in this case anthropocentric, choice. I already made the point that I'm free to choose a pendulum or similar oscillator, as having a unit period, so seconds don't appear; my choice of a unit of time does.
     
  16. Write4U Valued Senior Member

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    How does that follow?
    What does human activity have to do with time?
    You are asking the wrong questions.

    Do regular orbits "keep" time or do they "create" time?
    Does time exist in the future?
    If a clock keeps time where is this time stored? Inside the clock?
    If there is no clock of any kind, where does time go?
    Does time require time to exist?
    Can you measure time with time?
     
    Last edited: Oct 31, 2020
  17. Michael 345 New year. PRESENT is 71 years old Valued Senior Member

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    So my choice - second, also your choice - pendulum or similar oscillator, BOTH choices are NOT invariant

    Write4U can handle the rest of your rubbish

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  18. Write4U Valued Senior Member

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    This may be of interest;

    Records management theory
    Records life-cycle[edit]
    Main article: Records life-cycle
    Records continuum theory
    Main article: Records Continuum Model
    https://en.wikipedia.org/wiki/Records_management#Records_life-cycle

    Records continuum model
    (Redirected from Records Continuum Model)

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    The records continuum model
    https://en.wikipedia.org/wiki/Records_continuum_model

    IMO, Time is a human cognition and symbolization of measurable duration intervals associated with the creation, existence, and chronology of all change resulting in physical expression.
     
    Last edited: Oct 31, 2020
  19. arfa brane call me arf Valued Senior Member

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    How would you know the speed of light, or of anything, if no clocks existed? You asked "suppose there is no clock". But there are always clocks.
    Good question. What does any activity have to do with time? Perhaps it's only that activity is only possible if time exists.
     
  20. Michael 345 New year. PRESENT is 71 years old Valued Senior Member

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    Not so

    Any activity can exist and happen. Who determines if it should be timed is the correct question?

    If there is no requirement for any activity to be timed, don't bother. If you want it to be timed then select your arbitrary time units and time it

    Since all time units are arbitrary I maintain the position fundimental TIME does not exist and what is commonly put forward as time is a invented CONCEPT

    How you going with that list of properties of TIME?

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  21. Write4U Valued Senior Member

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    Actually we don't know the actual speed of light except as a relative constant value as measured against external conditions.

    All human numbers are symbolic representations of relative and relational values, but have real existence in reality.

    The relative values exist, the human record keeping is formalized, symbolized, structured for human convenience.
    This is why Einstein could propose that time actually stands still @ SOL .

    If Time existed as an independent continuous plenum, how could it stand still? Because it's all relative...

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  22. arfa brane call me arf Valued Senior Member

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    Strawman. We do know that our units of time and distance give us the speed of light in our units. We also know there is no reason to suppose they are different anywhere else in the locally-observable frame.
     
  23. arfa brane call me arf Valued Senior Member

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    So, an activity can happen. Is that because there is time for it to happen? What does that have to do with measuring units of time?
     

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