Notices
Results 1 to 48 of 48

Thread: What is time?

  1. #1 What is time? 
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    I start this discussion with my own definition of time.

    Time is the interval that relates physically two sequential moments of changes.


    Last edited by Asexperi@; September 12th, 2020 at 03:10 AM.
    Reply With Quote  
     

  2.  
     

  3. #2  
    Genius Duck Moderator Dywyddyr's Avatar
    Join Date
    Jan 2013
    Location
    Scunthorpe, UK
    Posts
    11,820
    So, no change = no time?


    "[Dywyddyr] makes a grumpy bastard like me seem like a happy go lucky scamp" - PhDemon
    Reply With Quote  
     

  4. #3  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Quote Originally Posted by Dywyddyr View Post
    So, no change = no time?
    Correct.
    Reply With Quote  
     

  5. #4  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,592
    Quote Originally Posted by Asexperi@ View Post
    I start this discussion with my own definition of time.

    Time is the interval that relates physically two sequential moments of changes.
    How do you define "change"?

    Do any consequences follow from your definition of time as compared to ,say the well known one :"time is what clocks measure"?
    Reply With Quote  
     

  6. #5  
    Genius Duck Moderator Dywyddyr's Avatar
    Join Date
    Jan 2013
    Location
    Scunthorpe, UK
    Posts
    11,820
    Quote Originally Posted by Asexperi@ View Post
    Quote Originally Posted by Dywyddyr View Post
    So, no change = no time?
    Correct.
    Then your "definition" is wrong.
    "[Dywyddyr] makes a grumpy bastard like me seem like a happy go lucky scamp" - PhDemon
    Reply With Quote  
     

  7. #6  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Quote Originally Posted by geordief View Post
    Quote Originally Posted by Asexperi@ View Post
    I start this discussion with my own definition of time.

    Time is the interval that relates physically two sequential moments of changes.
    How do you define "change"?

    Do any consequences follow from your definition of time as compared to, say the well known one :"time is what clocks measure"?
    Change means motion, phenomenon.

    "Time is what clocks measure" says nothing about time is.
    Reply With Quote  
     

  8. #7  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Quote Originally Posted by Dywyddyr View Post
    Quote Originally Posted by Asexperi@ View Post
    Quote Originally Posted by Dywyddyr View Post
    So, no change = no time?
    Correct.
    Then your "definition" is wrong.
    Why is it wrong ?
    Last edited by Asexperi@; September 12th, 2020 at 05:19 PM.
    Reply With Quote  
     

  9. #8  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,592
    ,Change = motion =phenomenon?

    I was not asking you to accept the validity of "time is what clocks measure".I was asking what material difference your definition makes as compared to that definition.
    Reply With Quote  
     

  10. #9  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Quote Originally Posted by geordief View Post
    ,Change = motion =phenomenon?

    I was not asking you to accept the validity of "time is what clocks measure". I was asking what material difference your definition makes as compared to that definition.
    My definition refers to two sequential moments related physically. Physically because a state x of phenomena depends on the previous states. For example: A journey does not end if it does not start, passing through different places.

    Asexperia
    Reply With Quote  
     

  11. #10  
    Genius Duck Moderator Dywyddyr's Avatar
    Join Date
    Jan 2013
    Location
    Scunthorpe, UK
    Posts
    11,820
    Quote Originally Posted by Asexperi@ View Post
    For example: A journey does not end if it does not start, passing through different places.
    And yet, if you simply sit in your car without going anywhere time still passes.
    "[Dywyddyr] makes a grumpy bastard like me seem like a happy go lucky scamp" - PhDemon
    Reply With Quote  
     

  12. #11  
    Forum Freshman
    Join Date
    Dec 2011
    Posts
    98
    Quote Originally Posted by Dywyddyr View Post
    Quote Originally Posted by Asexperi@ View Post
    For example: A journey does not end if it does not start, passing through different places.
    And yet, if you simply sit in your car without going anywhere time still passes.
    Playing devil's advocate here: If one simply sits in their car without going anywhere, there is still change: the driver's heart still beats, the planets continue in their orbits, others drive their cars to and fro, atomic vibrations persist etc.
    Reply With Quote  
     

  13. #12  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Quote Originally Posted by Vexspits View Post
    Quote Originally Posted by Dywyddyr View Post
    Quote Originally Posted by Asexperi@ View Post
    For example: A journey does not end if it does not start, passing through different places.
    And yet, if you simply sit in your car without going anywhere time still passes.
    Playing devil's advocate here: If one simply sits in their car without going anywhere, there is still change: the driver's heart still beats, the planets continue in their orbits, others drive their cars to and fro, atomic vibrations persist etc.
    All are changes that have a beginning and an end (time).
    Reply With Quote  
     

  14. #13  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Quote Originally Posted by Dywyddyr View Post
    Quote Originally Posted by Asexperi@ View Post
    For example: A journey does not end if it does not start, passing through different places.
    And yet, if you simply sit in your car without going anywhere time still passes.
    Obviously, there is a great diversity of changes. So, I am not wrong.
    Reply With Quote  
     

  15. #14  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    TIME IS MAGNITIVE
    (This concept was created by Asexperia in September 16, 2017.)

    Magnitive is derived from magnitude. Time is magnitive because is objective, imperceptible and measurable.

    We see changes, but not time. Time flows sequentially. We know time sequentially.
    Last edited by Asexperi@; September 13th, 2020 at 07:18 AM.
    Reply With Quote  
     

  16. #15  
    Genius Duck Moderator Dywyddyr's Avatar
    Join Date
    Jan 2013
    Location
    Scunthorpe, UK
    Posts
    11,820
    Quote Originally Posted by Asexperi@ View Post
    Quote Originally Posted by Dywyddyr View Post
    Quote Originally Posted by Asexperi@ View Post
    For example: A journey does not end if it does not start, passing through different places.
    And yet, if you simply sit in your car without going anywhere time still passes.
    Obviously, there is a great diversity of changes. So, I am not wrong.
    I agree that there are changes - I was merely highlighting that your example is deeply flawed, and as such isn't valid support for your argument. You'll have to do better.
    TIME IS MAGNITIVE
    (This concept was created by Asexperia in September 16, 2017.)
    Magnitive is derived from magnitude. Time is magnitive because is objective, imperceptible and measurable.
    Making up your own words - without providing a definition - doesn't help your case.
    (If it's impercetible then how do we know it's passing?)
    Time flows sequentially. We know time sequentially.
    And?
    "[Dywyddyr] makes a grumpy bastard like me seem like a happy go lucky scamp" - PhDemon
    Reply With Quote  
     

  17. #16  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Quote Originally Posted by Dywyddyr View Post
    (If it's impercetible then how do we know it's passing?)
    For its consequences:

    1- The continuous increase of the duration or measure of time.
    2- Aging.
    3- Material deterioration.
    Reply With Quote  
     

  18. #17  
    Forum Sophomore
    Join Date
    Jan 2019
    Posts
    124
    Asexperi@ will essentially repeat the above post over and over for as long as he is allowed. No further explanations or refinement, just repeating the same statements over and over and over...
    Reply With Quote  
     

  19. #18  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Quote Originally Posted by Bufofrog View Post
    Asexperi@ will essentially repeat the above post over and over for as long as he is allowed. No further explanations or refinement, just repeating the same statements over and over and over...
    This is a discussion forum, what are your arguments against my ideas?
    Reply With Quote  
     

  20. #19  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,592
    Quote Originally Posted by Asexperi@ View Post
    Quote Originally Posted by Bufofrog View Post
    Asexperi@ will essentially repeat the above post over and over for as long as he is allowed. No further explanations or refinement, just repeating the same statements over and over and over...
    This is a discussion forum, what are your arguments against my ideas?
    You didn't answer my post #8 . If it is a discussion forum you have to address each point or say why not.

    Your ideas are your own . If do do not communicate them in such a way as to attract interest ,you will get little feedback.
    Reply With Quote  
     

  21. #20  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Quote Originally Posted by geordief View Post
    Change = motion = phenomenon?
    Yes, they are synonymous.
    .......................

    The change-interval duality is the nature of time. Magnitive is/was its ineffable quality.

    We see one aspect of time (changes) and we measure its other aspect (interval).
    Reply With Quote  
     

  22. #21  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    What is your opinion about time?

    1- It's objective (real).
    2- It's subjective (an ilussion).
    3- It's subjective (a priori).
    4- It's magnitive (real).
    5- Other
    Reply With Quote  
     

  23. #22  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,592
    Quote Originally Posted by Asexperi@ View Post
    What is your opinion about time?

    1- It's objective (real).
    2- It's subjective (an ilussion).
    3- It's subjective (a priori).
    4- It's magnitive (real).
    5- Other
    Have no idea what "magnitive " means.

    Time is probably different things depending on context and how the word is used .

    Of course it can be a measure of intervals between events ,where it seems to be paired ,siamese -twin like with the spatial interval.

    As we experience it in our consciousness a pandora's box is opened but ,until there is a decent science of consciousness we can only make stabs as to what role it may play there.

    I am sure there are many schools of thought both in science and philosophy but my touchstone is ,as I indicated above ,whether any of the ideas allow for different outcomes(are scientifically verifiable) or a just an excuse for an exchange of views and cogitation (no bad thing in itself).
    Reply With Quote  
     

  24. #23  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Quote Originally Posted by geordief View Post
    Quote Originally Posted by Asexperi@ View Post
    What is your opinion about time?

    1- It's objective (real).
    2- It's subjective (an ilussion).
    3- It's subjective (a priori).
    4- It's magnitive (real).
    5- Other
    1- Have no idea what "magnitive " means.

    2- Time is probably different things depending on context and how the word is used.
    1- Magnitive is the essential quality of time of being objective, imperceptible and measurable.

    2- Any examples ?
    Reply With Quote  
     

  25. #24  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,592
    Quote Originally Posted by Asexperi@ View Post

    1- Magnitive is the essential quality of time of being objective, imperceptible and measurable.

    2- Any examples ?
    I really only had the scientific use versus the philosophical use, but I don't claim expertise.

    Don't find that definition helpful really , but again that can just be my lack of insight.
    Reply With Quote  
     

  26. #25  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Philochrony (from Greek philo = friend and khronos = time) is the natural science that describes the nature of time and demonstrates its existence. Philochrony originated in March 13, 2009.

    The concept change-interval duality originated in June 30, 2019.

    Also Philochrony performs a classification of beings accorging to their duration.
    Reply With Quote  
     

  27. #26  
    Genius Duck Moderator Dywyddyr's Avatar
    Join Date
    Jan 2013
    Location
    Scunthorpe, UK
    Posts
    11,820
    Quote Originally Posted by Asexperi@ View Post
    Philochrony (from Greek philo = friend and khronos = time) is the natural science that describes the nature of time and demonstrates its existence. Philochrony originated in March 13, 2009.
    Philochrony is NOT a science (natural or otherwise): it's made up crap.
    The concept change-interval duality originated in June 30, 2019.
    And hasn't progressed any further than empty claims since then.
    Also Philochrony performs a classification of beings accorging to their duration.
    Really?
    Classify the following:
    Frogs.
    Humans.
    Horses.
    And explain how this "classification" in any way improves on the current method.
    "[Dywyddyr] makes a grumpy bastard like me seem like a happy go lucky scamp" - PhDemon
    Reply With Quote  
     

  28. #27  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Quote Originally Posted by Dywyddyr View Post
    Philochrony is NOT a science (natural or otherwise): it's made up crap.
    Hahaha. That's your personal opinion.
    Philochrony is a science and it has answered correctly to your questions.
    You must know first about Philochrony to realize its usefulness.
    Last edited by Asexperi@; September 17th, 2020 at 10:52 AM.
    Reply With Quote  
     

  29. #28  
    Genius Duck Moderator Dywyddyr's Avatar
    Join Date
    Jan 2013
    Location
    Scunthorpe, UK
    Posts
    11,820
    Quote Originally Posted by Asexperi@ View Post
    Hahaha. That's your personal opinion.
    Nope, it's a fact.
    Philochrony is a science
    Provide citations.
    and it has answered correctly to your questions.
    And yet you haven't posted those "answers".
    You must first know about Philochrony to realize its usefulness.
    I try not to fill my mind with unsupported bullshit.
    "[Dywyddyr] makes a grumpy bastard like me seem like a happy go lucky scamp" - PhDemon
    Reply With Quote  
     

  30. #29  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    PHILOCHRONY: NATURAL SCIENCE

    1- Object of study: nature of time.

    2- Method: observation and register of the phenomena duration.

    3- Instruments: clocks, calendars and Chronology.

    4- Verifiability: any researcher can verify that:

    a) Time is the interval that physically relates two sequential moments of changes.

    b) Time is objective, imperceptible and measurable (magnitive).

    c) The timelines of phenomena can be unified into a single scheme (parallelochron).
    Last edited by Asexperi@; September 23rd, 2020 at 01:54 PM.
    Reply With Quote  
     

  31. #30  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    PHILOCHRON CLASSIFICATION OF BEINGS

    According to their duration, things are classified in: Eternal, lasting, perishable, ephemeral, fleeting and non-existent.

    A) Eternal things have no beginning nor end; as space. For believers, God and Paradise are eternal.

    B) Lasting things last a long time. They are divided into:

    - Centenarians, if they last from 100 to 999 years. For example the spruce tree and the saguaro cactus.

    - Millennials, from 1000 to 999,000 years. The redwood trees.

    - Millionaires, more than a million years. The geological eras, the life of planets and stars.

    C) Perishable things are short-lived; they last from one day to 99 years. The life of the human being.

    D) Ephemeral things are short-lived, some hours.

    E) The fleeting things are of very short duration, some seconds or fractions of second. The flicker, the heart rate.

    F) Non-existence is lack of existence, without duration. Planet X between Mars and Jupiter. All things have existence and essence.

    Asexperia, September 16, 2012
    Last edited by Asexperi@; September 19th, 2020 at 03:16 PM.
    Reply With Quote  
     

  32. #31  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    SAINT AUGUSTINE AND PHILOCHRONY

    Saint Augustine said: "If nobody asks me what time is, I know, but if they ask me and I want to explain it, I don't know anymore." We all experience what time is, but it really is not easy to understand, and of course, it is not easy to imagine a world without it, since it would be a world without a present, without movement and without rest.

    Physics teaches us that time is a fundamental magnitude and that is relative, but Physics does not tell us what is the nature of time.

    Physics manages time in relation to the movement of bodies in space.

    For Philochrony, time is the sequential and continuous occurrence of phenomena delimited for a start and an end. The change-interval duality, the magnitive time and the parallelochron explain time.

    Saint Augustine was aware of the existence of time, but He did not know how to explain it.
    Last edited by Asexperi@; September 23rd, 2020 at 04:53 PM.
    Reply With Quote  
     

  33. #32  
    Forum Sophomore
    Join Date
    Jan 2019
    Posts
    124
    Quote Originally Posted by Asexperi@ View Post
    Physics teaches us that time is a fundamental magnitude and that is relative
    Nope. Physics teaches us that time is a dimension.
    Reply With Quote  
     

  34. #33  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,592
    Quote Originally Posted by Bufofrog View Post
    Quote Originally Posted by Asexperi@ View Post
    Physics teaches us that time is a fundamental magnitude and that is relative
    Nope. Physics teaches us that time is a dimension.
    Suppose we want to measure the distance from ,say Liverpool to the Sun and back can this be done purely as a spatial distance or must such a measurement include a time component?

    Must we say that the distance is about 16 light.minutes or can we separate the time from the spatial distance?
    Reply With Quote  
     

  35. #34  
    Forum Sophomore
    Join Date
    Jan 2019
    Posts
    124
    Quote Originally Posted by geordief View Post
    Suppose we want to measure the distance from ,say Liverpool to the Sun and back can this be done purely as a spatial distance or must such a measurement include a time component?
    Just distance.

    Must we say that the distance is about 16 light.minutes or can we separate the time from the spatial distance?
    ?? 16 light minutes is just distance.
    Reply With Quote  
     

  36. #35  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,592
    Quote Originally Posted by Bufofrog View Post
    Quote Originally Posted by geordief View Post
    Suppose we want to measure the distance from ,say Liverpool to the Sun and back can this be done purely as a spatial distance or must such a measurement include a time component?
    Just distance.

    Must we say that the distance is about 16 light.minutes or can we separate the time from the spatial distance?
    ?? 16 light minutes is just distance.
    So the spacetime interval is just a measure of "distance" between events and not objects?
    (I said 16 light.minutes as the return journey.That would have made sense wouldn't it?)
    Reply With Quote  
     

  37. #36  
    Forum Sophomore
    Join Date
    Jan 2019
    Posts
    124
    So the spacetime interval is just a measure of "distance"
    events and not objects?
    The space time interval is a time and distance between 2 events.
    (I said 16 light.minutes as the return journey.That would have made sense wouldn't it?)
    All I said was that a light minute is a measure of distance.
    Reply With Quote  
     

  38. #37  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,592
    Quote Originally Posted by Bufofrog View Post
    So the spacetime interval is just a measure of "distance"
    events and not objects?
    The space time interval is a time and distance between 2 events.
    (I said 16 light.minutes as the return journey.That would have made sense wouldn't it?)
    All I said was that a light minute is a measure of distance.
    Ah ,sorry ,I wrongly interpreted your double question mark as puzzlement as to why I wrote "16" (unfamiliar with your punctuation )


    Yes ,I must have been labouring under the misapprehension that "light.years" was some kind of a spatial temporal measurement when it is indeed fairly obvious that it is a distance even if confusingly it does contain a temporal component (years)

    I wonder (scratching my head) whether there is a similar term that might represent a length of time...Would "light.metres" be a length of time perhaps and be measured in seconds?

    (If it was in use,obviously;I don't imagine it is)
    Reply With Quote  
     

  39. #38  
    Forum Sophomore
    Join Date
    Jan 2019
    Posts
    124
    I wonder (scratching my head) whether there is a similar term that might represent a length of time...Would "light.metres" be a length of time perhaps and be measured in seconds?

    A light year was adopted simply because the interstellar distances are so huge. It is easier to write 1 ly than to write 9,461,000,000,000 km. Time is represented by good old seconds, minutes, hours and years, they work fine.
    Reply With Quote  
     

  40. #39  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,592
    Quote Originally Posted by Bufofrog View Post
    I wonder (scratching my head) whether there is a similar term that might represent a length of time...Would "light.metres" be a length of time perhaps and be measured in seconds?

    A light year was adopted simply because the interstellar distances are so huge. It is easier to write 1 ly than to write 9,461,000,000,000 km. Time is represented by good old seconds, minutes, hours and years, they work fine.
    So ,what are the units of spacetime intervals?

    They would have to incorporate both spatial and temporal measurements,don't they?

    Edit: quick Google search leaves me little wiser
    https://physics.stackexchange.com/qu...space-distance
    Reply With Quote  
     

  41. #40  
    Forum Sophomore
    Join Date
    Jan 2019
    Posts
    124
    So ,what are the units of spacetime intervals?

    In general 2 observers in different inertial frames will disagree on the distance and time that 2 events occur.

    The spacetime interval is a specific thing. The spacetime interval is the invariant distance and time between 2 events. That means that by using the spacetime interval equation, 2 observers in different inertial frames will agree on the spacetime interval. The spacetime interval is made up of 3 spatial and 1 time dimension. To make the units the same for all 4 terms, the time is multiplied by the speed of light so it becomes a distance, therefore you get the following:

    ds^2=dx^2 + dy^2 + dz^2 - (c dt)^2

    The result will be in the units of distance, but as you can see time is in the equation so what this is giving us is the separation of 2 events in spacetime not just a space separation.

    Last edited by Bufofrog; September 25th, 2020 at 10:20 AM.
    Reply With Quote  
     

  42. #41  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,592
    Quote Originally Posted by Bufofrog View Post
    So ,what are the units of spacetime intervals?

    In general 2 observers in different inertial frames will disagree on the distance and time that an event occurs.

    The spacetime interval is a specific thing. The spacetime interval is the invariant distance and time between 2 events. That means that by using the spacetime interval equation, 2 observers in different inertial frames will agree on the spacetime interval. The spacetime interval is made up of 3 spatial and 1 time dimension. To make the units the same for all 4 terms, the time is multiplied by the speed of light so it becomes a distance, therefore you get the following:

    [tex]ds^2=dx^2 + dy^2 + dz^2 - (c dt)^2[\tex]

    The result will be in the units of distance, but as you can see time is in the equation so what this is giving us is the separation of 2 events in spacetime not just a space separation.


    So the units of spacetime (as formulated**) are a distance ? So two observers in different frames will look at two events at a third location and calculate a (spacetime)distance that both will agree on.?

    The unit of that distance could be the metre(or cm or mile etc etc) ,even though a unit of time was included in the formula to make the calculation ?

    So ,if we have two observers ,one on Earth and one on Mars calculating the spacetime interval between 2 sunspot events on the Sun they will both calculate a spatial distance*** that will likely extend from an agreed point (the first sunspot location ,for example) out into the Solar system or further ???

    **not that any other formulations are possible that would show the required invariance...

    *** they actually calculate a spacetime interval but this can also be represented as a purely spatial distance
    Reply With Quote  
     

  43. #42  
    Forum Sophomore
    Join Date
    Jan 2019
    Posts
    124
    I am not a physicist or mathematician and probably not the right person to try and explain this but I will try.

    Just about any calculation in special relativity can be done without ever even considering the Spacetime Interval. Length contraction, time dilation, the twin paradox, etc. are worked out without considering the Spacetime Interval.

    The Spacetime Interval is a rank 1 tensor (vector) in 4 dimensional space. A tensor it is invariant, that means the magnitude and direction are unaffected by a change in the coordinate system. In other words observers in 2 different inertial frames will agree on the magnitude and direction of the tensor.

    A rank 1 tensor in 3 spatial dimensions has a magnitude of distance.

    A rank 1 tensor in 3 spatial dimensions and 1 time dimension does not have a magnitude of distance! Even though the units are in kilometers (for instance) it is not just distance, there is a time component in it so it is called an interval. Thinking that a Spacetime Interval is a distance is not correct.

    So ,if we have two observers ,one on Earth and one on Mars calculating the spacetime interval between 2 sunspot events on the Sun they will both calculate a spatial distance


    They would be able to calculate the same interval, not the spatial distance. In the the Spacetime Interval we are calculating a quantity in spacetime not a quantity in space or time.

    I hope everything I have written is correct, I am notoriously sloppy in math speak...
    Reply With Quote  
     

  44. #43  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Quote Originally Posted by Bufofrog View Post
    Quote Originally Posted by Asexperi@ View Post
    Physics teaches us that time is a fundamental magnitude and that is relative
    Nope. Physics teaches us that time is a dimension.
    Quote Originally Posted by Bufofrog View Post
    So ,what are the units of spacetime intervals?

    In general 2 observers in different inertial frames will disagree on the distance and time that 2 events occur.

    The spacetime interval is a specific thing. The spacetime interval is the invariant distance and time between 2 events. That means that by using the spacetime interval equation, 2 observers in different inertial frames will agree on the spacetime interval. The spacetime interval is made up of 3 spatial and 1 time dimension. To make the units the same for all 4 terms, the time is multiplied by the speed of light so it becomes a distance, therefore you get the following:

    ds^2=dx^2 + dy^2 + dz^2 - (c dt)^2

    The result will be in the units of distance, but as you can see time is in the equation so what this is giving us is the separation of 2 events in spacetime not just a space separation.
    Time is a dimension in the Theory of Relativity and you have to use the speed of light (c) to convert time into distance. By the way, the light year is a unit of distance not time.
    Reply With Quote  
     

  45. #44  
    Forum Sophomore
    Join Date
    Jan 2019
    Posts
    124
    Thanks for adding nothing to the conversation.
    Reply With Quote  
     

  46. #45  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    Quote Originally Posted by Bufofrog View Post
    Thanks for adding nothing to the conversation.
    Hahahaha

    With spacetime Physics does not explain the nature of time. Physics just explains c.

    Now we have regular and irregular (relative) time.
    Last edited by Asexperi@; September 25th, 2020 at 03:34 PM.
    Reply With Quote  
     

  47. #46  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,592
    Quote Originally Posted by Bufofrog View Post
    I am not a physicist or mathematician and probably not the right person to try and explain this but I will try.

    Just about any calculation in special relativity can be done without ever even considering the Spacetime Interval. Length contraction, time dilation, the twin paradox, etc. are worked out without considering the Spacetime Interval.

    The Spacetime Interval is a rank 1 tensor (vector) in 4 dimensional space. A tensor it is invariant, that means the magnitude and direction are unaffected by a change in the coordinate system. In other words observers in 2 different inertial frames will agree on the magnitude and direction of the tensor.

    A rank 1 tensor in 3 spatial dimensions has a magnitude of distance.

    A rank 1 tensor in 3 spatial dimensions and 1 time dimension does not have a magnitude of distance! Even though the units are in kilometers (for instance) it is not just distance, there is a time component in it so it is called an interval. Thinking that a Spacetime Interval is a distance is not correct.

    So ,if we have two observers ,one on Earth and one on Mars calculating the spacetime interval between 2 sunspot events on the Sun they will both calculate a spatial distance


    They would be able to calculate the same interval, not the spatial distance. In the the Spacetime Interval we are calculating a quantity in spacetime not a quantity in space or time.

    I hope everything I have written is correct, I am notoriously sloppy in math speak...
    Just taking the spacetime interval as it is written ,is there a physical meaning for the term(ct)^2 ?


    I always assumed it was the square of the distance that light travelled in t seconds.

    And that the physical meaning of the whole expression was the difference between the square of a spatial distance in the x,y x coordinate system and the square of a distance travelled by a beam of light in the same coordinate system.

    The light travels far,far ... far further than the spatial distance between the two events but both can be compared because they are both spatial distances.

    I agree that the spacetime interval is not a simple spatial distance but would you not agree that is the difference between two spatial distances?

    It seems to me to represent the ratio of the physical distance moved by one event from another event compared to the physical distance it would have moved if it had been traveling at the maximum speed possible (the speed of light or perhaps the speed of causality)

    I am ,like you neither a mathematician nor a physicist and my assumptions normally turn out to be wrong.

    Pity we no longer have Markus on this site ,but we have him over at another forum and he (or Swansont or someone else) might answer my related question over there in the next few days or so.
    Reply With Quote  
     

  48. #47  
    Forum Freshman Asexperi@'s Avatar
    Join Date
    Sep 2020
    Location
    Florida, USA
    Posts
    24
    DIFFERENT VIEWS ABOUT TIME

    Time is a physical magnitude that affects all reality, but we do not have a specific sense to perceive the intervals. This makes each person get a different idea about the nature of time. There is no consensus on what time is.

    1- Heraclitus of Ephesus (philosopher): becoming flows like a river, it is the Being.

    2- Parmenides of Elea (philosopher): there are no changes, there is no time.


    3- Aristotle of Estagira (philosopher): time exists when movement involves a number.


    4- Galileo Galilei (physicist): movement is relative. If A moves with respect to B, B moves with respect to A.


    5- Isaac Newton (physicist): time is real and absolute.


    6- Immanuel Kant (philosopher): time is an a priori form.


    7- Albert Einstein (physicist): time is an illusion and relative.


    8- Henri Bergson (philosopher): rejected mathematical time.


    9- Martin Heidegger (philosopher): time is the being-there or dasein, time is temporary.


    10- Julian Barbour (physicist): time does not exist.


    11- Paul Davies (physicist): defends the unidirectionality or arrow of time.


    12- Josť Ignacio Latorre (physicist): time is a parameter that relates two movements.


    13- Lee Smolin (physicist): time is real.


    14- Bradford Skow (philosopher): past, present and future coexist in the universe.


    15- David Eagleman (neurobiologist): time is invented by the brain.


    16- Elvis Sibilia (psychologist): time is magnitive, that is, objective, imperceptible and measurable.


    Meaning of colors:

    Blue: time exists (5)
    Black: intermediate (5)
    Red: time does not exist (6)
    Reply With Quote  
     

  49. #48  
    Forum Radioactive Isotope
    Join Date
    Feb 2009
    Posts
    4,592
    Quote Originally Posted by Asexperi@ View Post
    DIFFERENT VIEWS ABOUT TIME

    Time is a physical magnitude that affects all reality, but we do not have a specific sense to perceive the intervals. This makes each person get a different idea about the nature of time. There is no consensus on what time is.

    1- Heraclitus of Ephesus (philosopher): becoming flows like a river, it is the Being.

    2- Parmenides of Elea (philosopher): there are no changes, there is no time.


    3- Aristotle of Estagira (philosopher): time exists when movement involves a number.


    4- Galileo Galilei (physicist): movement is relative. If A moves with respect to B, B moves with respect to A.


    5- Isaac Newton (physicist): time is real and absolute.


    6- Immanuel Kant (philosopher): time is an a priori form.


    7- Albert Einstein (physicist): time is an illusion and relative.


    8- Henri Bergson (philosopher): rejected mathematical time.


    9- Martin Heidegger (philosopher): time is the being-there or dasein, time is temporary.


    10- Julian Barbour (physicist): time does not exist.


    11- Paul Davies (physicist): defends the unidirectionality or arrow of time.


    12- Josť Ignacio Latorre (physicist): time is a parameter that relates two movements.


    13- Lee Smolin (physicist): time is real.


    14- Bradford Skow (philosopher): past, present and future coexist in the universe.


    15- David Eagleman (neurobiologist): time is invented by the brain.


    16- Elvis Sibilia (psychologist): time is magnitive, that is, objective, imperceptible and measurable.


    Meaning of colors:

    Blue: time exists (5)
    Black: intermediate (5)
    Red: time does not exist (6)
    Those are interesting opinions. The proof of the pudding ,though is how these opinions translate into verifiable predictions.

    I think it may well have been Henri Poincare who , before Einstein was the first to allow each observer to have his own clock in his or her own frame of reference

    Whoever ,it was that was a genius idea and imo lead to the advances ushered in by Special and General Relativity .

    Bravo Henri!
    Reply With Quote  
     

Similar Threads

  1. Is crossing time zones actually real life time traveling?
    By Zimmery "Reece Ran" Mac in forum Personal Theories & Alternative Ideas
    Replies: 6
    Last Post: February 3rd, 2014, 06:36 AM
  2. Replies: 7
    Last Post: September 12th, 2013, 12:29 AM
  3. Replies: 2
    Last Post: May 20th, 2013, 06:59 AM
  4. Replies: 2
    Last Post: February 4th, 2008, 06:50 PM
  5. Time is space-time, is motion-interval, defining distance?
    By That Rascal Puff in forum Personal Theories & Alternative Ideas
    Replies: 0
    Last Post: July 6th, 2006, 11:54 PM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •