# What really is a continuous symmetry?

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

1. ### Write4UValued Senior Member

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No, still backwards. Time is not causal to change. Time is a result of change.
Moreover, light is only a constant in a vacuum. Light travels at variable speeds dependent on medium.

Time is the measurable result of duration of physical change from start to finish.
The constant speed of light over a distance yields a constant measurable duration of time, after the light reaches its destination and distance and duration can be measured. But the speed of light traveling through water slows down and affects the time of duration of travel over a distance.
Time
https://en.wikipedia.org/wiki/Time

Conclusion: Time can only travel forward in time as it always is an additive result of duration.

3. ### Write4UValued Senior Member

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That's all human created theory.
Time is a human invention and is an abstract mathematical object used for measurement of duration.

river likes this.

5. ### arfa branecall me arfValued Senior Member

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I'm glad I didn't make that mistake then.
Or, time has a constant rate of change. I don't think that's a mistake on my part.
No, the speed of light is constant in an homogenous medium.
Except nobody actually measures time; we have to convert it into a distance to 'measure' it, in which case, we measure a distance which is a time-equivalent.
'sigh'. So time travels, forwards, in . . . time? I see.

7. ### Write4UValued Senior Member

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15,852
It started raining 3 days ago. It stopped raining this morning. How long did it rain?

8. ### Write4UValued Senior Member

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15,852
It started raining 3 days ago. It stopped raining this morning. How long did it rain?

Time is not Distance. You can measure Distance, you cannot measure Time.
Any measurement of time is a human created arbitrary artifact.
We make the clocks that tick and in that process produce the emergent durations (time) between clocks ticks .
If you want to compare this to Distance then it is like measuring a "meter" with a ruler of 1 meter.

What does it mean the clock is "fast" or "slow"? Does the clock rate of ticks determine the rate of flow of Time?
And is any clock even a useful tool to examine Time that the clock itself "produces" from the Present into the Future. Tic - Toc (ad infinitum)

Time
https://en.wikipedia.org/wiki/Time

Time is a human invented abstract mathematical tool to account for the Human observation of chronologically occurring events and the experience of duration by and between those events that are causal to deterministic future results.

As reality progresses from past to future, the chronology of events is always an additive quantity from past to future. This results in the "forward " direction of the "arrow of emergent time"

1 + 1 = 2 +3t (the three seconds it took me to type this)......

Duration
https://en.wikipedia.org/wiki/Duration_(philosophy)

Time is an emergent measurement of abstract numbers associated with variable chronological durations of "unfolding" reality via deterministic causal change.

Time is a result (an emergent value) of measurable change. The "Seasons"

Last edited: Nov 2, 2020
9. ### arfa branecall me arfValued Senior Member

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Which is why we build devices that output a distance, we claim these devices have time as the input although that isn't strictly true.
What about other animals who can tell the difference between night and day? they don't measure time?

Animals don't remember events? I can't see why they would survive very long in that case.

And although the phrase "measure time" is already wrong, because time isn't measured-- clock-distances are--we can still assume that time is continuous and has a constant 'gradient', so that time rates of change are the same for all clocks in some local frame.

10. ### Write4UValued Senior Member

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15,852
It's all arbitrary.
Yes, regularities tend to imprint on biological life.
Only very few animals consciously remember into the far past. But "fight or flight" response has proven to be very successful in the evolution of species.
Naahh....all questions about time can be answered by the understanding that time is an abstract creation as a result of a chronologically ordered process. The process produces several simultaneous time lines as a result of "duration" of process. These are all abstractions of a quantitative "description" of duration.

The expression that "Time began with the BB" is a measurement of duration from the distant past (memory) and measurable duration from "then" to "now. Before the BB there was NO time. There was not need for time to exist.
It was a a timeless condition which was somehow causal to the emergence of this Universe with its Mathematical regularities, which can be practically exploited for survival pf the species.

A Mayfly does not eat. It has no mouth. It needs no mouth. It lives 24 hrs during which Mayflies seek mates, mate , lie eggs , and die. In relation to a turtle, 1 Mayfly lifetime equals 1 day in the hundred year lifetime of a turtle, or the time it takes to travel from one tree to another tree, for a three-toed sloth....

Sloths: The World's Slowest Mammals
By Alina Bradford - Live Science Contributor November 26, 2018
https://www.livescience.com/27612-sloths.html

Last edited: Nov 2, 2020
11. ### arfa branecall me arfValued Senior Member

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Well, I'm glad that one got cleared up.
And you can see the problem with a timeless condition being "causal", since causality and timelessness don't commute, as they say.
So we really still have no answer for how time got started.

12. ### Write4UValued Senior Member

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15,852
That was never in dispute.
Well, talk to Lawrence Krauss about that.
Yes we do, time began with the "inflationary epoch". And it got started with the duration of formation and continued existence of the universe, spacetime.

13. ### arfa branecall me arfValued Senior Member

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I dispute that. The arbitrariness is either just the way we assign arbitrary units to time and distance, or it's the arbitrary relative motions of observers. But time itself is not arbitrary; it's a fundamental property of our universe. Everyone understands time until you ask them to explain it.
Why should I believe what he has to say (see above)?
So inflation was the first event? Before inflation there was no time, so no events? Or maybe time did exist but didn't flow, for some reason? Or, maybe . . . nobody will ever be able to explain the source of regular, constant time-flow? "It is what it is"

Except as one of the symmetries of nature? But what is that symmetry, or do we only have mathematical symmetries that seem to mimic nature, for reasons we don't need to explain?

14. ### Write4UValued Senior Member

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You keep answering your own question. Time is a fundamental property of the UNIVERSE, because of the continued measurable existence of the universe.
Prior to the Universe there was neither space nor time.

IMO "time" is no more than mathematical (physical) "permission" for chronological change within the Universal space.
Time becomes measurable as "durations" of permitted change.
Similar to Force becoming measurable as the "rate of change" in momentum.
No change, no force, no time.....

The assumption that time exist independent of change makes it unnecessarily complicated. The assumption that force exists independent of change makes it unnecessarily complicated.

Keep it simple
The fundamental properties of the universe are not complicated.

3 spatial dimension create space (room) and mathematical permission for change within that space. When change in space occurs, mathematically measurable durations of change are created and can be symbolized as arbitrary increments of Time.
In relation to what and as a result of what? To itself? Or to the continued existence of the Universe......???

Last edited: Nov 2, 2020
15. ### arfa branecall me arfValued Senior Member

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You mean "what really is a continuous symmetry?".

What about the assumption that time exists even in parts of the universe that are free of events? Time would be independent where there are no changes, unless you went there with a clock, say.
Oh really? Why have so many pages been written about it, why bother if it's not complicated? Of course they're complicated; largely because we still don't really understand the fundamental properties.

16. ### arfa branecall me arfValued Senior Member

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. . . time has a constant rate of change.
For one, in relation to the spontaneous propagation of light; a result of which is the accurate timing of light's propagation over an arbitrarily chosen distance.

17. ### Write4UValued Senior Member

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What light? No Universe no light, no light no time.

You keep introducing change inside the spacetime configuration which necessarily have associated durations of time.
Time ONLY applies to permitted change inside the spacetime configuration.

No Space, No symmetry, No Time, Nothing!

Last edited: Nov 2, 2020
18. ### arfa branecall me arfValued Senior Member

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??
So what? Aren't we discussing this universe?

19. ### Write4UValued Senior Member

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No one is disputing the term "spacetime", that's accepted science.
But that does not mean that there is "timetime" as an independent dimension. Time exists only because the 3 other physical dimensions exist.
Take away space and poof, there goes time right along with it. Time is a result of the continuous symmetry of the Universe. Hence the scientific term "spacetime" (time as an emergent product of duration of space)

Necessity and Sufficiency.
https://en.wikipedia.org/wiki/Necessity_and_sufficiency

When there is no necessity for time, time does not exist. When time is a necessity, sufficient time emerges for that specific necessity. There is no requirement that time needs to exist, for it to spontaneously emerge when chronological durations make it necessary.

Last edited: Nov 3, 2020
20. ### arfa branecall me arfValued Senior Member

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You're sure that's why?

If you are, then that means you're unique among humans. Congratulations, how does it feel?
The universe doesn't have a continuous symmetry we call time, it has a result of a continuous symmetry? Which one?
But the universe is expanding; this also occurs in "time-free" regions where time isn't "necessary"? How does that work?
But time is always a necessity; since the universe began to expand continuously. Expansion necessarily entails time to expand.
Well, I think that's just wrong. Sorry about that.

Last edited: Nov 3, 2020
21. ### Write4UValued Senior Member

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Because it needs not be otherwise.
I'm NOT alone in this.
OK, to me time is the result of the continuation (duration) of the universe. I don't think that time has anything to do with symmetry per se. The universe has symmetry albeit dynamical. Symmetry breaking has duration and requires time.
It creates time during the expansion.
Exactly, I completely agree. It has expanded continuously since the "beginning".
Why is that wrong? Why should there be time of duration when there is no process or change that has duration and necessitates time?
Necessity -- Sufficiency.

22. ### arfa branecall me arfValued Senior Member

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Ok, so if I understand anything Write4U is saying, the universe has been expanding continuously since it began.

But we also observe this expansion is the same everywhere. So if as Write4U says, time is created during the expansion, then it must be created the same everywhere. Perhaps that explains the constant speed of light.
On the other hand, the expansion could be smooth because time is a continuous symmetry.

Or maybe one of those is wrong? I just can't see how anything can expand without time to do so. Instead, time apparently emerges because the universe is expanding. But expansion is change; change without time doesn't make any sense.

Indeed trying to claim, as Write4U seems to be, that change is more fundamental than time begs the question: how does change exist without time? don't time and change imply each other (like, really strongly)?

23. ### Write4UValued Senior Member

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15,852
Actually IMO, it has been expanding and contracting since the beginning.
...

....

Is our universe ringing like a crystal glass?
Posted by Deborah Byrd in SCIENCE WIRE | SPACE | June 26, 2015

Artist’s concept of an oscillating or ‘ringing’ universe. Image via NASA, via University of Southern Mississippi

The Astronomical Journal published their paper on this topic in April.
https://earthsky.org/space/is-our-universe-ringing-like-a-crystal-glass

Notice the "flattening" of the Universal "Pilot Wave" function.
I agree. But that does not contradict the notion that time of duration emerges along with the duration of change or duration of plain existence.
How can time (duration) exist without change? Therein lies the crux of the matter.

IMO, the logic suggests that a deterministic physical "cause" for change preceeds the "duration" of the process/function of change. However, the measurement of "duration" (time) does become part of the "resulting" equation in the "effect".

They not only imply each other, they are mathematically necessary and sufficient to each other.
Necessity -- Sufficiency

But in the absence of physical existential necessity, time has no independent existence. When it is not needed (absence of duration), the absence of time is sufficient in and of itself.

Last edited: Nov 3, 2020