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Atlas3
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Does Universe Spacetime have clock of it's own? A period?
What spacetime are you talking about?Atlas3 said:Does Universe Spacetime have clock of it's own? A period?
I will need to familiarize myself with what you have described. I have considered many parallel universes of infinite size experiencing periodicity of life time. Big Crunch ending like a bang beginning. But other parallel universes experiencing their own time period independently. A massive universal period. A function of time normalized 0 to 1 period of expansion / contraction of each whole. Please keep in mind I am going to familiarize myself with the suggestions above as someone may be on this train of thought. I thank youbahamagreen said:Are you asking if the block (universe) has a clock (spacetime subject to change of configuration)?
I believe the block universe idea suggests that for the entire configuration of spacetime the "history" is fixed, but if the block universe can change configuration it would seem that the entire history would become different but still consistent (as we know it). We would not know of the change because it includes all of the history, including all the consistent memories. To track a change would require being "outside" of the changing spacetime with some way to compare the previous configuration to a subsequent configuration... but there is not accounting for "outside" and any measures from within a changing spacetime would always be consistent.
The closest thing I can think of is perhaps the Many Worlds interpretation - but instead of the many worlds you might have "many configurations" of spacetime, each generation of another world really being the expression of a change in spacetime configuration (and each of those changes presenting a consistent self history)... the Many Worlds is liked for its power and consistency but it also requires "thinking outside the block"... :)
That's not a viable clock model, as there's no way to measure across different big bang/crunch events. Also, if there are many big bang/crunch events, chances are the period of time associated with each varies dramatically.Atlas3 said:I will need to familiarize myself with what you have described. I have considered many parallel universes of infinite size experiencing periodicity of life time. Big Crunch ending like a bang beginning. But other parallel universes experiencing their own time period independently. A massive universal period. A function of time normalized 0 to 1 period of expansion / contraction of each whole. Please keep in mind I am going to familiarize myself with the suggestions above as someone may be on this train of thought. I thank you
Time exists as a period of many things. Solar time for example is one. Earth rotation provides one for instance. Expansion of the universe has a period as well. We don't know the period of he universe.Chalnoth said:What spacetime are you talking about?
In general, I'd have to say the answer is no: clocks are built from matter. It would certainly be possible to use gravity as part of your clock design (in a way, the Earth's orbital period is a sort of clock). But you still need matter involved to make it work (if there's no Earth and no Sun, the "orbital period of the Earth" doesn't make any sense).
Chalnoth said:That's not a viable clock model, as there's no way to measure across different big bang/crunch events. Also, if there are many big bang/crunch events, chances are the period of time associated with each varies dramatically.
Looks like you were cut off.Atlas3 said:Time exists as a period of many things. Solar time for example is one. Earth rotation provides one for instance. Expansion of the universe has
Atlas3 said:Time exists as a period of many things. Solar time for example is one. Earth rotation provides one for instance. Expansion of the universe has[/QUOT
Atlas3 said:Time exists as a period of many things. Solar time for example is one. Earth rotation provides one for instance. Expansion of the universe has a period as well. We don't know the period of he universe.Can you give a little explanation how you suppose why the period would vary? I think it would as well but cannot put but a few words on it. I have the same idea but it is because it would vary depending upon the maturation of the universe, and that would vary with random circumstances after an event.
The overall process of a repeating reconfiguration could be considered a pulse. Periodic but varying periods does not make a regulated clock but it does make a wave which could not be measured by us. But could be time proceeding. It can't be measured by us. We would not exist any longer nor would our reference frame for time. A reconfiguration would reset the maturation period which would vary. Also consider more than one universe experiencing this life.Chalnoth said:Looks like you were cut off.
It's possible to use the expansion of the universe to set a specific meaning for "now" (when the CMB has the same average temperature at every point). But it's still not really possible to use the expansion as a clock of any sort. Clocks typically depend upon having predictable, repeating behavior, and the expansion of our universe doesn't do that.
That is, you can use the expansion to sync up clocks that are far away, but you can't use it as a clock in and of itself.
Atlas3 said:The overall process of a repeating reconfiguration could be considered a pulse.
Atlas3 said:Can the fabric of space time be considered to exist in isolation of matter?
Can spacetime be constructed without matter? Mathematically.PeterDonis said:Since there is matter in the universe, we have no way of testing whether spacetime could exist in a universe with no matter at all.
Atlas3 said:Can spacetime be constructed without matter? Mathematically.
Can curved spacetime be described within Minkowski spacetime as a system?PeterDonis said:Yes, flat Minkowski spacetime is a mathematical solution to the Einstein Field Equation with zero stress-energy (and zero cosmological constant). But again, because there is matter in our actual universe, this mathematical solution does not describe it.
I agree it could not be used as a clock in the time keeping sense. But does the possibiltity of periodicity in expansion allow negative expansion?Chalnoth said:Looks like you were cut off.
It's possible to use the expansion of the universe to set a specific meaning for "now" (when the CMB has the same average temperature at every point). But it's still not really possible to use the expansion as a clock of any sort. Clocks typically depend upon having predictable, repeating behavior, and the expansion of our universe doesn't do that.
That is, you can use the expansion to sync up clocks that are far away, but you can't use it as a clock in and of itself.
Thank you for your answers to my questions. It astonishing to me that I had the physical thought to think was a possibility. I came up with this without being taught or research. I had a moment of pure physics one night. Actually cosmology. I only reached a point in education recently to formulate questions to what i imagined in my mind one night. I have been pursuing this in college for a few years since. Now I am finding out things like this are possibilities in fact. Its amazing and thank you again.PeterDonis said:Yes, flat Minkowski spacetime is a mathematical solution to the Einstein Field Equation with zero stress-energy (and zero cosmological constant). But again, because there is matter in our actual universe, this mathematical solution does not describe it.
Atlas3 said:does the possibiltity of periodicity in expansion allow negative expansion?
PeterDonis said:If by "negative expansion" you mean "contraction", then yes, there are mathematical solutions that describe contracting universes.
Atlas3 said:can the contraction and expansion be a cycle without a crunch or bang mathematically?
It's over my head. Never read such discussion.Chronos said:The 'block' universe concept has been widely discredited. See http://en.wikipedia.org/wiki/Eternalism_(philosophy_of_time) for discussion.
What type of geometry, in the shape sense, is the current model. That may not be possible to demonstrate. I was shown a depiction of a balloon inflating with the matter within. I was also shown that we are within a horizon surrounded by CMB in all directions I think. I think my questions of construction of ( not necessarily ours ) geometry have been answered as much as I was interested. I at least have an idea of the Euclid geometry to further consider. This thread was started about a time definition because I wasn't sure about how the time dimension in geometry was included in math. I recommend closing the topic. I will ask later about a flat metric for further inquiry after I get a better question.PeterDonis said:No; at least, not with classical GR. There are speculations that quantum effects might allow a "bounce" scenario where contraction turns around and becomes expansion before a crunch/bang occurs; but those are just speculations at this point.
This is something I may want to discuss. I'm learning this bulletin board. Can I quote this reply when starting a new thread or maybe we could open a conversation to rattle this reply around some time? Thank you also for the reply.russ_watters said:Note that you do not need a periodic process to have a usable clock, you only need a process with a predictable pattern or rate. You could, for example, measure the speed an object is traveling at, then use distance measurements (whenever you want) to calculate elapsed time. As long as the speed is predictable (it doesn't even need to be constant), you can use it to calculate time. Indeed, the age of the universe is calculated in exactly that way.
Because of that, in my particular dialect (Philadelphian), we use time and distance interchangeably.
Q: "How far are you from Philadelphia?"
A: "About 35 minutes."
The time parameter as it pertained to Euclid geometry and spacetime construction. The range as needed from initial to end for definition. That dimensional component I think has a particular range. My original post was actually titled poorly. I've added a little more comprehension of it though. Also I asked in a separate thread which was vague about dilation. Dilation only in the mathematical sense and how it applies to the dimension of time mathmatically for construction of a geometry. Two related questions. If someone would prefer to edit this thread it may be of more use. Especially the title. Thanks for helping me.PeterDonis said:What would it mean for spacetime to "have a clock of its own"?
Atlas3 said:The time parameter as it pertained to Euclid geometry and spacetime construction. The range as needed from initial to end for definition.
Either would be fine with me, but as you can see, I may not notice...Atlas3 said:This is something I may want to discuss. I'm learning this bulletin board. Can I quote this reply when starting a new thread or maybe we could open a conversation to rattle this reply around some time? Thank you also for the reply.
The "clock and period" of the universe refers to the idea that the universe may have a natural rhythm or cycle that governs its behavior. This could include patterns of expansion and contraction, the formation and destruction of galaxies, or other cosmic processes.
While there is ongoing research and speculation about the concept of a universal clock and period, there is currently no scientific evidence to support its existence. The universe is incredibly complex and dynamic, making it difficult to pinpoint a single governing rhythm.
Time dilation is a well-established phenomenon in physics, but it is not directly related to the idea of a universal clock and period. Time dilation occurs when an object is moving at high speeds or in a strong gravitational field, causing time to appear to pass at a different rate for an observer. The concept of a universal clock and period is more focused on the overall rhythm of the universe, rather than individual objects within it.
The concept of a universal clock and period is not a widely accepted or integrated aspect of current theories of the universe, such as the Big Bang theory or the theory of general relativity. While some scientists may explore the idea in their research, it is not a fundamental component of our understanding of the universe at this time.
If evidence were to emerge supporting the existence of a universal clock and period, it could potentially challenge our current understanding of time and the universe. It may also open up new avenues for research and lead to a deeper understanding of the fundamental laws that govern the universe.