Is There A Universal Now?

Discussion in 'Physics & Math' started by Cyperium, Jun 14, 2022.

  1. Mike_Fontenot Registered Senior Member

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    (Almost) anytime someone draws a diagram with more than one spatial dimension, they're already on the wrong track. The key to understanding special relativity is to chose the SIMPLEST scenario that can address the question of interest. That almost always means that the chosen scenario should involve only one spatial axis (and one time axis, of course).
     
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  3. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

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    If, like me who has a belief time is non existent, is it acceptable for me to count my singular now as being a substitute for non existent time?

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  5. Mike_Fontenot Registered Senior Member

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    If you think time is non existent, you're not talking about physics ... you're just talking mumbo-jumbo.
     
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  7. Write4U Valued Senior Member

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    I don't use clocks in my argument. Any mention of clocks by me was to illustrate the futility of the example of any observer inside the spacetime geometry that does not allow a non-relativistic perspective.
    the Universe doesn't need any clocks at all to continue its existence as a singular object.
    Observers inside the universe need clocks to calculate the differential equations that determine a unified NOW from the observer's POV.

    The universe as a whole doesn't care about any of that. It just continues to chronologically extend its existence @ every emergence of measurable NOWs equally distributed over the entire "surface" of the universe that is moving in a single direction forward into a timeless non-dimensional permittive condition of nothingness, aka, the future.

    Time of duration emerges in a single direction for all extant objects at the same a priori
    rate. Any relative deviation of time occurs inside the already extant larger worldline of the universe (spacetime) itself.
     
    Last edited: Sep 19, 2022
  8. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

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    OK

    Numerous physicists have written about the subject of why time maybe non existent

    If you think time exist please provide some information about time's properties and / or the means by which time is / has been detected

    Thanks

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  9. Mike_Fontenot Registered Senior Member

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    Einstein said "Time is what clocks measure."
     
  10. Write4U Valued Senior Member

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    Time of what do clocks measure? Time of time? Time of duration? Time of gaps between durations?
     
  11. Mike_Fontenot Registered Senior Member

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    Einstein's definition of time was good enough for him, so it's good enough for me.
     
  12. James R Just this guy, you know? Staff Member

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    How can you make an observation from outside the Universe? There isn't an outside, as far as we can tell.
    Can I substitute the word "events" for your "NOWS" and keep your meaning? Or is there some kind of relevant difference in what you're saying?
    Okay. My mistake.

    So, you think that at some time there was no time (or no "NOWs", perhaps), and then time (or NOWs) came into existence? I'm fine with that idea. It's what the big bang theory says, more or less.
    Only conscious beings can have experiences, as far as I'm aware. What else can have an experience, according to you?
    I don't actually think the notion of a conscious observer is important to relativity. If that's what you're suggesting I'm saying, that's not what I'm saying, and I don't think I've ever made that claim. We can define frames of reference without appealing to conscious observers.

    Yes, yes. I'm aware you can google things and consult wikipedia. But I'm still wondering whether you actually understand what a differential equation is, because whenever you refer to differential equations the context of your writing doesn't actually reference any particular differential equation.
     
  13. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

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    Interesting
    So you don't respond by providing
    you quote Einstein

    Would you contend that clocks measure what humans have defined as time?

    We defined the duration of a second and following our defining the duration of a second we built a mechanism to measure the duration of a second

    Sounds a bit circular

    Where is the existing free range second, the one you claim exist?

    AND

    If there is a free range second out there should not our efforts be put into detecting that second, not making up our own?

    Any thoughts about the duration of a free range second? Longer or shorter than our defined second?

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    Last edited: Sep 20, 2022
  14. Write4U Valued Senior Member

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    This is why I do not place a clock or an observer anywhere. I am not claiming there is an outside from the universe except nothingness. But AFAIK, there is an outer limit to the universe itself, else the universe could not be expanding, no? Hence we may assume that the universe is an expanding singular object
    and therefore has an individual lifeline consisting of a chronological accumulation of 13.8 billion years of NOWS
    IMO, yes. Events occur inside the universe and may create their own NOWs separately from the Universal NOW.
    Exactly!

    Trusting the science that proposes the big bang and the absolute lack of knowledge of what was before the big bang, I visualized that before the BB there was only anfinite, timeless, dimensionless, permittive condition of nothingness.
    According to Krauss that scenario should not be rejected out of hand.

    If that is stipulated, then the BB was the beginning of everything we know. But as inflation occurred in a purely permittive condition, the rate of energetic expansion was @ FTL until the energetic plasma cooled and the first particles began to self-form from the Chaos. It is at this point measurable time of duration emerged and added a temporal aspect to the expanding wholeness and attached a universal temporal dimension to the continued spatial existence of the universal wholeness.

    I know this sounds simplistic, but I am an absolute denier of "irreducible complexity"and "something from nothing" seems the least complex scenario that can be imagined.
    Therein lies the crux. At what point does the expanding universe acquire mathematical properties and dynamic guiding principles that permit some interactions and forbid other interactions and here I agree with the concept that physical interactions of inherent generic elemental values cannot do other than what a logical generic mathematical language allows or forbids the output of certain specific results from specific value inputs. Universal constant functions that allowed the self-formation and emergence of the first physical patterns from the early inflationary chaos.
    Wonderful, now we are no longer talking past each other and can address the problem from an objective perspective.

    I believe you are still visualizing this from an inside perspective and I agree that time becomes a relativistic variable. I have no quarrel with SR. My position is very simple. The Universe is a singular dynamic object that is subject to the emergence of time along with its duration of existence. I am not making any other claim about any internal interactive mathematics between generic "relational values".
    But that is exactly what you have been discussing all along "synchronizing clocks in accordance with the appropriate differential equations" over time.

    As bookkeeper and bid-supervisor I used "differential equations" for several economic predictions that required time-dependent derivative answers.

    "A derivative is the rate of change of something with respect to something else. You can, for instance, model changes in revenue with respect to changes in capital expenditure—that would be a derivative. Also common are models which explain changes in price with respect to time."

    You have heard me cite the exponential function. This is a logical (first order ) differential equation because the exponential function equals its own derivative.
     
    Last edited: Sep 20, 2022
  15. James R Just this guy, you know? Staff Member

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    People observed regular cycles of nature long before anybody thought of defining the second.

    For instance, people noticed that night follows day and then a new day comes along, then it's night again. That started those smart cookies thinking: "Hey! Things aren't always the same. Could we perhaps quantify how fast things change, somehow?" And so, the concept of a "day" was born: probably one of the first measurements of time.

    Mechanical clocks that measure seconds were still a long way off, back in those days. But time existed nevertheless.
    Have you ever noticed a difference between night and day, michael?
     
  16. Michael 345 New year. PRESENT is 72 years oldl Valued Senior Member

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    What has one (observing regular cycles of nature) got to do with the other (defining the second)?

    Can you stitch them together for me please?

    Oh you mean defining days not seconds - OK

    Sure. So when did the first free range second get measured by a mechanical clock?

    It is / was great free range seconds were around (existed) when a mechanical clock was invented to measure them ✅

    The inventor would look silly inventing a clock to measure seconds when no seconds existed

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    My question (repeated below) still awaits an answer

    If there is a free range second out there should not our efforts be put into detecting that second, not making up our own?

    While you ask

    Of course not. I've always worked shift work

    (Where is the sarcasm font when you need it?)

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  17. James R Just this guy, you know? Staff Member

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    Michael 345:
    I'll get to that below. But I thought you were denying, more generally, that time exists. Hence, I was trying to draw your attention to a different way to measure time that doesn't involve seconds.

    If you're not denying that time exists, after all, then we can still talk about seconds if you like, but I'd say the discussion is then rather lower-stakes.
    I can't say exactly, but if I had to guess I'd say that it was probably around the time that clocks were invented that were sufficiently accurate to keep time to the second, over some substantial period.

    Historically, you can trace the development of clocks from prehistoric humans observing the cycles of day/night, the seasons etc. through to sundials, to water clocks, to pendulums, to spring-loaded clockwork with mechanical oscillators, to crystal oscillators, to atomic clocks. Notice how these roughly go from least to most accurate, in terms of measuring time.
    Yes!

    The second was original defined not by reference to any mechanical clock, of course, so it pre-dated such clocks. The second was originally defined as 1/60th of an hour, and the hour was defined as 1/24th of a day, and the day was defined by the Sun's apparent position in the sky (which is, of course, related to the Earth's rotational period).
    The units aren't actually that important to a clock. A clock is good if it keeps time accurately over a reasonably long period. It is not so good if it drifts out of sync and tells you it is midnight when it is actually 2 o'clock in the afternoon.
    Our current clocks detect/measure seconds just fine - some much better than others, obviously.

    The fact that we choose to use seconds is as much historical accident and convenience as anything else. The units don't really matter. At one stage, the French proposed that we all ought to decimalise time, but the idea never really caught on with the general public.

    What we want a clock for is to tell us when it's time to get up and go to work, when it's time to go pick up the kids from school - that sort of thing. Useful things, clocks, it turns out.
     
    Last edited: Sep 20, 2022
  18. James R Just this guy, you know? Staff Member

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    Write4U:

    There's no need for an outside.

    A common analogy for this is the loaf-of-raisin-bread picture. The universe is like an unbaked loaf of raisin bread. The raisins represent galaxies and the bread represents space. We put the bread in the oven to bake it and the bread expands. All of the raisins in the loaf move away from one another as the loaf expands.

    The analogy breaks down because the loaf of bread has edges. So now imagine an infinite loaf, still full of raisins, baking in an infinite oven. The raisins still all move away from one another as the bread expands, but now there is no "outside" that the loaf is expanding into. Everything is loaf.

    The universe is like that.
    In the "block time" picture from relativity, events are points in spacetime. They do not "create" anything. We can talk about other events that are simultaneous with any given event, but if we're going to do that we must first specify a particular frame of reference, because there is no "preferred" or "universal" time.
    Personally, I don't think the phrase "before the big bang" has been defined well enough to give it any clear meaning for me. In the general relativistic descriptions, time starts at the moment of the big bang. There is no "before" in those descriptions.

    Perhaps it is possible to define some kind of time-like thing separate from our observable universe. In Hawking's A brief history of time, I read some stuff about "imaginary time", but I don't really understand what he was on about with that. Probably I don't know enough general relativistic cosmology.

    Krauss's definition of "nothingness" (e.g. in his book A universe from nothing) is a bit slippery, I think. As far as I can tell, he suggested some kind of quantum field that fluctuated to cause the big bang. I personally wouldn't describe any quantum field as "nothing".

    You keep mentioning "permittive" nothingness. You even emphasise the word "permittive". What does that mean? Does it mean anything more than you're imagining a prior condition that permits a big bang to occur, similar to Krauss's quantum field?
    I don't know what you mean by a "purely permittive condition". What are the degrees of "permittivity"? What would a partially permittive condition look like?
    GR cosmological theories have time already running during the proposed inflationary period. Your own hypothesis sounds different to that.
    The least complex scenario I can imagine for the universe would be the so-called steady-state theory, in which the universe stays approximately the same at all times. Observational data refuted that hypothesis, however.
    I don't know what you mean by "mathematical properties". If you just mean the universe has properties that we can describe using mathematics, then I'd say the universe probably had those from the moment of the big bang. I'm not saying that our current mathematical theories provide a full description of the entire evolution of the universe, because of course they don't.

    You write as if you think that "universal constant functions" can cause physical effects. They cannot. Mathematics is an abstraction - an idea in your head. Mathematics doesn't create "stuff" or cause physical effects (Tegmark notwithstanding).
    Okay. I can live with that. I agree that the universe is a thing, and that it has time and that it has existed for quite a while now.
    I don't think so. Where did I mention any differential equations?
    Yes, a derivative is a rate of change of something with respect to something else. A simple physical example would be speed, which is the rate of change of distance with respect to time. Technically, there is an important difference between instantaneous speed and average speed. Mathematically, average speed is just total distance travelled divided by total time taken, but instantaneous speed is the derivative $dx/dt$, which involves the idea of a mathematical limit as the time interval becomes infinitesimally small.

    A differential equation is any equation that includes a derivative. Technically, the equation $v(t)=dx/dt$ is a differential equation. This one has many possible solutions. For example, if velocity is a constant, $v_0$ say, then we have $dx/dt=v_0$, which means $x(t) = v_0 t + k$, where $t$ is the time variable and $k$ is some other constant (which in this case turns out to be the position at time $t=0$). Much more complicated differential equations exist, some of which involve higher-order derivatives. Here's one example:
    $\frac{d^2 x}{dt^2} +\omega^2 x = 0$.
    This one describes simple harmonic motion, which is a type of regular oscillatory motion. The derivative in the first term, in this case, is a second order derivative of distance with respect to time (which is actually the acceleration). One "solution" to this particular equation is:
    $x(t) = A \sin (\omega t)$
    which, again, gives us a description of how the position, $x$ of some object changes as the time variable $t$ changes.
    Mathematically, the relevant differential equation would be something like
    $\frac{dn}{dt} = 0.693 n$
    where, for example, the variable $n$ could be the number of rabbits in a population at a given time $t$. In this case, the differential equation says "the rate of increase in the number of rabbits per unit time is 0.693 times however many rabbits are currently alive".

    One possible solution to this differential equation is:
    $n(t) = 2^t$, which would mean that at time $t=1$ there are 2 rabbits, at time $t=2$ there are 4 rabbits, at time $t=3$ there are 8 rabbits, at time $t=5$ there are 32 rabbits, at time $t=10$ there are 1024 rabbits, at time $t=20$ there are 1,048,576 rabbits and so on, which is an example of exponential growth. (They breed like rabbits!)
     
    Last edited: Sep 20, 2022
  19. Write4U Valued Senior Member

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    Question: What happens to NOW during daylight savings time? Does NOW gain or lose an hour from its original chronology? What happens to time during leap year? An entire 24 hrs of NOWs is gained.

    If time exists, won't all that clockwork differential play havoc with the orderly existence of time.

    OTOH, if time is an emergent result of duration, then any dimension of time can only be attached to actual duration of existence, or change, or in between, no?
     
  20. James R Just this guy, you know? Staff Member

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    Nothing happens to "NOW". NOW is whatever you're currently experiencing.

    Nothing happens to time in a leap year or when daylight saving time comes into effect. We just adjust our calendars or clocks when those things happen. That is, we assign different numerical values to the time coordinate we are using (dates or hours).
    "Time" doesn't care what we do with our clocks.
    Duration is just the difference between two times. 2 pm minus 12 pm is a two hour duration. 10 seconds minus 2 seconds is an 8 second duration. The duration of a breakfast that goes from 8:15 am to 8:45 am is half an hour.

    What are you talking about when you suggest taht "time is an emergent result of duration"? How can you define "duration" without appealing to some pre-existing idea about what time is?
     
  21. Write4U Valued Senior Member

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    There isn't an outside spatial dimension. There is only a timeless, dimensionless, permittive nothingness that allows the universe to expand at FTL without any limitation of any kind.

    This is what happened during the inflationary epoch, the free mathematically unrestricted expansion into nothingness.
     
  22. Write4U Valued Senior Member

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    Space does care what we do with it. How then can we use a term like "spacetime" if some space can exist without time.
    If time is emergent quality then it will always synchronize with the expansion of spatial cooedinates

    Duration is just the difference between two times. 2 pm minus 12 pm is a two hour duration. 10 seconds minus 2 seconds is an 8 second duration. The duration of a breakfast that goes from 8:15 am to 8:45 am is half an hour.[/quote] And all the while there are no NOWs?
    You just explained it above. If there is no breakfast then there will not be an emergent duration of that breakfast. Time does not emerge from "nothingness" and time does not exist in the future. It only emerges with the event and chronology of a set of NOWs
    Time emerges as a byproduct of duration of spatial "change"

    The universe doesn't keep time, it creates it.

    We haven't really defined duration have we? An oscillation by a caesium atom. {9,192,631,770 hertz (Hz = cycles/second)}, because it is a regular pattern?

    Sounds like an arbitrary human measurement to me.

    Question: If time stands still at SOL, does time even exists for a caesium atom?

    Is that why we have time measurement of "half-life"
     
    Last edited: Sep 20, 2022
  23. James R Just this guy, you know? Staff Member

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    How did you verify the existence of the timeless, dimensionaless, permittive nothingness? Or, if you haven't yet done so, how could you?
    It does? How so?
    The whole idea of spacetime is that it is a constant. Spacetime is the collection of all events that have ever happened, all events that are happening now, and all events that will ever happen in the future. You have a personal worldline that winds its way through the constant spacetime. "Now" is just the collection of events that, in your frame of reference, happen to be occurring simultaneously with one particular event on your own personal worldline.
     
    Last edited: Sep 20, 2022

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