Can you describe “a point in time”?
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I thouht that the Sunflower was Prometheus :shrug:
I should have responded to this earlier. A point in time, like the instant that a photon strikes the film is what I'm talking about. The image on the film records the point in time but as Prometheus says, photos are over a time interval. But as you point out there is a potential image at the point in time that the photon is recorded on the film.
So motion between two points in time has to be a vector that tells us distance and direction. If we recorded that information for every point in space from one frame to another though, we would get no vectors because objects move through space, space doesn't move. To get a vector we have to be talking about the change in location of whatever occupied the space in frame one. That object has to move in order for a vector to be defined.
There is only vector information between two points in time. "A vector is a specific mathematical structure. It has numerous physical and geometric applications, which result mainly from its ability to represent magnitude and direction simultaneously. Wind, for example, had both a speed and a direction and, hence, is conveniently expressed as a vector. The same can be said of moving objects and forces. The location of a points on a cartesian coordinate plane is usually expressed as an ordered pair (x, y), which is a specific example of a vector. Being a vector, (x, y) has a a certain distance (magnitude) from and angle (direction) relative to the origin (0, 0). Vectors are quite useful in simplifying problems from three-dimensional geometry."
The freezing of all points in space establishes a point of reference since there is no absolute space or time:
Invariance vs. covariance
I added the bold.wiki said:
Once we have frozen time at a universal "now" and have established a point in time and space for every object then we can move time forward and freeze a second time, and then we can compare motion between the two freeze frames. The points in space can be defined as invariant and the location of objects in space have shown a vector.
The vector information is direction and distance. Each vector spans multiple points in space and since we have established a frame of reference, we know which points in space have been spanned by each vector. Simple motion is thus determined in the classical sense as the number of points in space covered by the motion, and the direction in space can be determined in three dimensions. Therefor relative motion between any two objects, between all object can be defined.
Acitnoids has taken the relativistic view that all properties of an object are dynamical and what I want to do is go from the classical view of my reference points in space and time to the relativistic view and see if I can understand how and if there can be transformations made between the two.
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time ='s motion? that is some assumption and not true.
Maybe, maybe not. That is what we're exploring. Relativistically, my understanding is that objects follow geodesics and their motion is described by Einstein's Field Equations; there is no physical gravitational connection, only the curvature of space caused by the mass in that space and its relative position to other mass that exists in surrounding spacetime.
In my freeze frame example we have stopped time at a "now" to establish the location of objects in space. The next "now" can be used to establish motion vectors as Emos points out. The question is, are those objects following spacetime geodesics or are they influenced by gravity. Gravity, in my definition, establishes an inertial connection between all objects within space by influencing the energy density of space between them.
To understand how my view differs from spacetime you have to be able to say that space would exist even if there were no objects in it; even if there was no energy in it. It could be completely empty and still be space.
The distance between objects (a particle with mass is an object) in my freeze frame could be space that contains energy and has energy density. The energy density of that space between objects would vary based on the history of mass and motion but does not contain an object. So space between particles or objects would not contain any particles but would have energy density, i.e. energy would have to exist in space that contains no particles.
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Does this have anything to do with sonoluninescence? This is where a single bubble, suspended in a liquid medium, is trapped in an acoustic standing wave. The standing wave compresses the bubble to a minimim size which in turn produces a pulse of light and a inner temperature thought to exceed one million degrees Kelvin (but recently verified to be closer to 20,000 degrees Kelvin). I wanted to ask earlier but got distracted.
No. The bubble of nothing is a solution to GR (More or less, it's actually a solution to type IIB supergravity that contains GR).
PS, the unit of temperature you're looking for is the Kelvin, not degrees Kelvin.
PS, the unit of temperature you're looking for is the Kelvin, not degrees Kelvin.
To state the obvious, The freeze frame which would occur if we could invoke the universal “now” might have mechanical problems. There is uncertainty at the quantum level, only a mathematical description of gravity above the quantum level, and no precise picture of what reality really is. So we are freezing things so we can have a look.
When you freeze frame objects across the universe and go out there and muck around you might have a couple of destinations. For example you might be looking deep inside objects to examine particles. Are particles made up of complicated dimensions somehow established and maintained to give substance to energy? Is the universe finite like standard theory predicts? Would you go looking for a horizon which some might call the distance that light has traveled since electrons started emitting photons for the first time from within the Big Bang universe? Others might look for the horizon far beyond that due to faster than the speed of light expansion ala Alan Guth’s Inflationary Theory. They might be looking out there for an extended thermalized background of cosmic microwave radiation that extends well beyond the farthest galaxies. What would you expect to find upon close and far examination?
Does it boil down to relationalism vs. absolutism or invariance vs. covariance as described by Michael Friedman above in the Wiki quote? If so, what coordinate system are you using to set your expectations for what we will find? Are you willing to describe anything about what you think we will find based on the theories or ideas you adhere to? I know that you don't know what is out there beyond our current real time live action observable universe or deep inside of objects where subatomic particles interact so that is why I am invoking the freeze frame.
Let’s start with checking to see if the universe is finite. Since we froze it at a point in time and can muck around out there, how far would the universe reach and what would be going on out there now, or is there even an edge that would be discernible?
Let's go look.
When you freeze frame objects across the universe and go out there and muck around you might have a couple of destinations. For example you might be looking deep inside objects to examine particles. Are particles made up of complicated dimensions somehow established and maintained to give substance to energy? Is the universe finite like standard theory predicts? Would you go looking for a horizon which some might call the distance that light has traveled since electrons started emitting photons for the first time from within the Big Bang universe? Others might look for the horizon far beyond that due to faster than the speed of light expansion ala Alan Guth’s Inflationary Theory. They might be looking out there for an extended thermalized background of cosmic microwave radiation that extends well beyond the farthest galaxies. What would you expect to find upon close and far examination?
Does it boil down to relationalism vs. absolutism or invariance vs. covariance as described by Michael Friedman above in the Wiki quote? If so, what coordinate system are you using to set your expectations for what we will find? Are you willing to describe anything about what you think we will find based on the theories or ideas you adhere to? I know that you don't know what is out there beyond our current real time live action observable universe or deep inside of objects where subatomic particles interact so that is why I am invoking the freeze frame.
Let’s start with checking to see if the universe is finite. Since we froze it at a point in time and can muck around out there, how far would the universe reach and what would be going on out there now, or is there even an edge that would be discernible?
Let's go look.
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So here we are out at theoretically the farthest outpost of firmament; as far as you can get from Earth and still be standing on a patch of substance with enough continuity for us to stand on and look out at the universe from this unique perspective. It is cold dead matter that seems to have no useful energy but we haven’t gone deep inside it yet to examine the particles or composition. It just seems like some burnt out high entropy galactic remnant that saw its heyday billions of years ago.QW said:
Wait, I see a note here written in charcoal on a rock. It says, “No matter which way you look you will still seem to be in the center of the universe." I look around out into space and the note is right. Every direction is still filled with galaxies just like I saw from our Earth perspective. How can we be surprised? The cosmological principle says that is what we will see, a homogeneous and isotropic universes no matter where we are in space and no matter where we are in time.
I look at my watch and the time is now 2010 on Earth and 13.7 Universal Time. The coordinate system is set at “relativistic” and so it is spacetime where there are three spatial dimensions which are coupled with time in a spacetime continuum where objects and motion cannot be separated but are connected by geometry and geodesics.
Let me switch to the Euclidean three dimensions plus time and look around.
Wow, things are different. What do you think we would see from a Cartesian coordinate system in Euclidean space?
It would still be homogeneous and isotropic on a grand scale if we assume the cosmological principle, but the view would be entirely different.
Look at what the Cosmological Principle says and you will see why it is a pillar of cosmology. It explains why we would not be able to see the “outside” or “beyond” any finite universe; whatever the universe is, it is all there is
, nothing can be beyond it or outside of it under any circumstances.Cosmological Principle as stated by Wiki: “
“ The cosmological principle is usually stated formally as 'Viewed on a sufficiently large scale, the properties of the Universe are the same for all observers.' This amounts to the strongly philosophical statement that the part of the Universe which we can see is a fair sample, and that the same physical laws apply throughout. In essence, this in a sense says that the Universe is knowable and is playing fair with scientists.”
And:
“ … all points in space ought to experience the same physical development, correlated in time in such a way that all points at a certain distance from an observer appear to be at the same stage of development. In that sense, all spatial conditions in the Universe must appear to be homogeneous and isotropic to an observer at all times in the future and in the past.”
I’ll give up cosmology if the universe is not like that, but I’m not worried.
I’m going to write up what I think we would see from our freeze frame perspective at the farthest point from Earth if we were out there viewing the universe from a Cartesian coordinate system in Euclidean space. First I’ll assume a finite universe and then an infinite universe and show the comparison from my point of view.
Same time, same place, different coordinate system. I’m showing the difference in how the universe might look when you look at it from the perspective of spacetime vs. Euclidean space. My last post pointed out that from a spacetime perspective the universe would look like it does from Earth even if we were as far away from Earth as you can get in that spacetime coordinate system. Every point in the universe would look the same on a grand scale in spacetime so it has to look the same from Earth as from the farthest point from Earth.
Now, from a Cartesian coordinate system in Euclidean space I go to the farthest point from Earth in my frozen frame. If the universe is finite in content and infinite in space, from the edge I look around at the universe and I see our arena but I am clearly at the outer edge in 3-D space. When I look into our arena I see the same expanding set of galaxies that we know are all moving away from each other but I see that from the edge of the finite universe.
But that is not the whole picture because if our finite arena has an edge then there is space beyond and so according to the cosmological principle, if I look around I should see that on a grand scale I am not on the edge, I am again in the center of a greater universe.
So I turn and look out into the space beyond the edge of our finite arena and I see distant arenas across the landscape of the greater universe. Here is a pic I took (humor):
So that is the difference between my Spacetime coordinate system view of a finite universe and my view of a finite universe from a Cartesian coordinate system in Euclidean space.
If there is a finite universe in a spacetime coordinate system we cannot detect an edge and the view from any point in it is the same. If there is a finite universe in a Cartesian coordinate system of Euclidean space then there is infinite space that is not coupled with time. If that surrounding space is empty we are on our way to complete entropy. If that space is filled with arenas similar to our own as in the pic we could have a perpetual universe that defeats entropy.
Now, from a Cartesian coordinate system in Euclidean space I go to the farthest point from Earth in my frozen frame. If the universe is finite in content and infinite in space, from the edge I look around at the universe and I see our arena but I am clearly at the outer edge in 3-D space. When I look into our arena I see the same expanding set of galaxies that we know are all moving away from each other but I see that from the edge of the finite universe.
But that is not the whole picture because if our finite arena has an edge then there is space beyond and so according to the cosmological principle, if I look around I should see that on a grand scale I am not on the edge, I am again in the center of a greater universe.
So I turn and look out into the space beyond the edge of our finite arena and I see distant arenas across the landscape of the greater universe. Here is a pic I took (humor):
So that is the difference between my Spacetime coordinate system view of a finite universe and my view of a finite universe from a Cartesian coordinate system in Euclidean space.
If there is a finite universe in a spacetime coordinate system we cannot detect an edge and the view from any point in it is the same. If there is a finite universe in a Cartesian coordinate system of Euclidean space then there is infinite space that is not coupled with time. If that surrounding space is empty we are on our way to complete entropy. If that space is filled with arenas similar to our own as in the pic we could have a perpetual universe that defeats entropy.
Let’s look at the difference in entropy between the two coordinate systems. Spacetime of the standard cosmology, Big Bang Theory, locks in the increasing entropy. The Big Rip is a spacetime outcome that leads to complete entropy; ugly, very inelegant.
Cartesian coordinates in Euclidean space allow for the defeat of entropy by hosting interacting arenas that recycle old burned out galactic material into refurbished low entropy energy density; pretty, elegant, perpetual.
How does the recycling work in 100 words or less? The landscape of the greater universe is made up of arenas that form when two expanding arenas like our own overlap. The galaxies from each parent arena mix and merge in the overlap space. Gravity takes control leading to swirling rendezvous of galactic material which collapses into a big crunch. The critical capacity of a big crunch equals the galactic content of one parent and each parent contributes half of their galactic material to the crunch. The energy density of the crunch causes it to burst into expansion. A new expanding arena emerges from each crunch. It is a self-perpetuating process.
Cartesian coordinates in Euclidean space allow for the defeat of entropy by hosting interacting arenas that recycle old burned out galactic material into refurbished low entropy energy density; pretty, elegant, perpetual.
How does the recycling work in 100 words or less? The landscape of the greater universe is made up of arenas that form when two expanding arenas like our own overlap. The galaxies from each parent arena mix and merge in the overlap space. Gravity takes control leading to swirling rendezvous of galactic material which collapses into a big crunch. The critical capacity of a big crunch equals the galactic content of one parent and each parent contributes half of their galactic material to the crunch. The energy density of the crunch causes it to burst into expansion. A new expanding arena emerges from each crunch. It is a self-perpetuating process.
I don't necessarily agree with your conclusions so let me share how I would view a universe frozen in time. I am led to believe that time is its own spatial dimension. In other words, any movement through time correlates into a physical movement through an isolated spatial dimension (this is the single reference point I spoke of "out of the side of my mouth"). If you could freeze time then you would be preventing any movement through this isolated spatial dimension. Under normal conditions (time flowing), the point that you occupy (the point in space where you consider yourself to be) is separated from the visible horizon by a time. More specifically, these two points are separated by a distance equal to the age of your point in space. As you move away from your original point, with time flowing normally, the entire horizon would seem to shift with you. This illustrates that evey point in the universe should be considered the center of the universe relative to the horizon. When "freezing time", you have to define the point in space from which time was frozen. The further you move from that point, the younger/smaller the universe will appear (the horizon no longer shifts with you). The part that is counter intuitive says that, for any given moment in time (single frame), both points of view seem to be correct for your original point in space. If you choose to freeze time right here and then you move over there, over there would seem younger/smaller. If you choose to freeze time over there and then you move over here, over here would seem younger/smaller. In closing, you can never look into the universe from the horizon. Under normal conditions the horizon will always shift with you and under frozen conditions the horizon is the origin of the Big Bang. The distance between you and the visible horizon is one of the most important questions in cosmology. By deturmining the age of your point in space you are defining a point in time.
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Thank you for your participation and I acknowledge your view of the horizon. What you just described is the Spacetime coordinate system. At any point in spacetime the universe complies with the Cosmological Principle which I linked to in a recent post. Do you agree that the observable universe that is described by Spacetime complies with the Cosmological Principle as Wiki describes it (I’ll repost the link and Wiki’s description at the bottom of this post)?
You did a great job of describing the Spacetime perspective and I want to pick up on what you said about two distant points in spacetime.
The fact that any two points in spacetime can be transformed to a common reference frame means that what you see from two distant points in spacetime must be adjusted for the invariant speed of light. The wave length of light that reaches you is affected by the difference in frame, but the speed of the light that reaches you is always the same. Your description seems to acknowledge that fact and you probably are better at making the transformations that I am. It doesn’t mean that those two points in spacetime don’t exist at the same time, they do.
When I freeze time it just means that the histories of the objects that occupy those points in space are frozen at the same moment for further investigation. Where that adjusted moment is in the history of the objects in space can be determined for any two distant points in space by doing transformations. That means that we could adjust everything for our particular location and point in time. Do you agree? Because that is part of the requirement in defining a universal "now", i.e. any point can be transformed to the frozen time at any other point.
Here is the Cosmological Principle that I linked to earlier:
cosmological principle
Look at what the Cosmological Principle says and you will see why it is a pillar of cosmology. It explains why we would not be able to see the “outside” or “beyond” any finite universe. It reinforces the concept that whatever the universe is, it is all there is
, nothing can be beyond it or outside of it under any circumstances..Cosmological Principle as stated by Wiki: “
“ The cosmological principle is usually stated formally as 'Viewed on a sufficiently large scale, the properties of the Universe are the same for all observers.' This amounts to the strongly philosophical statement that the part of the Universe which we can see is a fair sample, and that the same physical laws apply throughout. In essence, this in a sense says that the Universe is knowable and is playing fair with scientists.”
And:
“ … all points in space ought to experience the same physical development, correlated in time in such a way that all points at a certain distance from an observer appear to be at the same stage of development. In that sense, all spatial conditions in the Universe must appear to be homogeneous and isotropic to an observer at all times in the future and in the past.”
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Just because you can adjust the two frames to fit a common reference does not mean that they must be adjusted. Remember, from your original point in space you can not say with any certainty what a common reference frame is so there is nothing solid to adjust every frame to.
Once again, just because they can does not mean that they do. It is completely dependent on the point from where you make the comparison.
Are you suggesting that all points in space can be frozen in time as if they were all the same age? This is the only way that I can imagine a universe that appears infinite in time and space. Such an assumption seems to disregard the fact that two points in space can occupy two different points in time.
I agree with the Wiki article but the quotes you provided are nothing more than vague descriptions by an astronomer named William Keel. They make sense when put into the context of the article but I caution you not to take Keel's quotes too literally. This is what the article is saying. It does not matter where you choose to make an observation of the universe because, when you look out from that point in space you will always see a homogenous and isotropic universe. This held true at the beginning of the universe and continues to hold true today.
Time is observation of movement, yet the smallest movement is to fill a space that becomes available. The Universe is a grain, and if the smallest grain were planck scale then the smallest movement would be planck scale. So time is the observation of movement over planck distance. But I don't like the word time, as it implies that the movement of the planck can be reversed. yet there is no gap behind the planck to move into, only a gap at the front. So really time doesn't exist, only movement exists.
It is admirable that you are not disputing anything I said but you are qualifying everything I said. You are also making me think that you adhere to the view that there is no single reality, but perhaps an infinite number of realities, the Copenhagen view and Many Worlds in the way some people view String Theory. Is that true?
I asked earlier what leads you to believe space is being created as the universe expands. I addressed your responses and am coming back to the question, “What leads you to believe that space is being created and that space has not always been infinite”?
A small issue I think, but the Cosmological Principe is part of the consensus. And I agree with your paraphrasing of it, but I find no difference between your version and what I posted from Wiki. Explain the difference if it means that your view is different from the way I quoted Wiki. Who is Keel?
Lol, I’m trying to carry on a discussion with you. You cautioned me to be careful not to pay too much attention to Keel and I said, “Who’s Keel” as if to say that I didn’t think I was paying too much attention to him. I assume you are giving me back the same kind of light hearted banter when you act as if Keel is someone that must be known and considered and then paid not much attention :shrug:.
You have a view of the universe that I’m asking you to support. At the same time I’m discussing various alternative views and coordinate systems for the very purpose of exploring various views.
If I admit to knowing who Keel is (I have not read his book, “The Road to Galaxy Formation”, though it is an interesting topic) will you answer the questions that I asked:
QW said:
QW said:
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I said this half out of friendly banter and half out of frustration. In posts 49 & 53 you gave a link to a Wiki article and a brief description that was a copy and paste from the article itself. What you copied and pasted was William Keel as quoted by Wiki. I had never heard of the man before you quoted him so when you asked me who he was, ... It made me wonder if you paid any attention to the article that you were linking to/quoting in the first place.
As far as I know there is only one reality that matters and that is the one that we are participating in. Could there be more than one reality? I guess so, but if there is then I am led to believe that they all originated from the same point as our reality. In all honesty, I don't know enough about these concepts to either support them or refute them.
Space is being stretched, not created. A point in space is an abstract concept (they exist where you say they exist). Even though you can place more points on an inflated balloon than a deflated balloon does not mean that you created more latex.
Time is just a measurement of motion no? I mean if there was absolutely no movement at all there would be no time and there would be no energy, so could there even be mass?
One allows the other to exist but none solely by themselves.
Movement allows mass to exist (atoms)
The movement of mass in space allows time to exist
And If I understand the basics correctly at all, there would be no energy or time if the movement of mass were not present.
How could anything be perceived as past, present, future when there is no movement to differentiate between the three? Past, present, future might as well all be the same with no movement or changes.
I’m thinking movement universally as if everything in the known universe stopped moving even the atoms that made up the mass.
Which leads me to another question are our perceptions a good indicator of reality? We can perceive an object as motionless or still, like the picture on your wall, but reality or physics says that the picture, you, and the planet you are on are all moving at the exact same speed through space, which is moving through the solar system which itself is moving through the galaxy which itself is moving etc.
I could go on all day wondering about all this stuff lol