What is time?

[RCP/CRT/RRT]

There is no "border" between future and past. There is only the ongoing present.[/b]

Amen!:)

Michael

 

Seems as if now/present would have no meaning were it not for past and future...

[modest]

"* Time goes more slowly in higher gravitational fields. This is called gravitational time dilation.*

 

If "time" here is not posited as an entity, then it should read, "The pace of physical processes slows down in higher gravitational fields. This is called gravitational slowing of physical processes."

 

Time is actually increased higher in a gravitational field (clocks tick faster). [edit: sorry, I misread that. Higher gravitational field is not the same as higher in a gravitational field] Nonetheless, the trouble you're having, which I've now said in 3 or 4 posts in a row, is that you don't understand that the word means the definition. If time = the pace of a physical process (by definition) then there is no difference between these two statements:

• Time is increased higher in a gravitational field.
  
• The pace of a physical process is increased in a higher gravitational field.
  

They are exactly equivalent. Yet, you agree with the second statement, but object to the first which makes no earthly sense to anyone who understands what a definition is.

 

You are treating time as something different from "that which a clock measures" or "the rate of a physical process". You reify time yourself then object to its reification. You should really stop that.

 

~modest

[Michael Mooney]

Originally Posted by Michael Mooney View Post

"* Time goes more slowly in higher gravitational fields. This is called gravitational time dilation.*

 

If "time" here is not posited as an entity, then it should read, "The pace of physical processes slows down in higher gravitational fields. This is called gravitational slowing of physical processes."

Modest:

Time is actually increased higher in a gravitational field (clocks tick faster). [edit: sorry, I misread that. Higher gravitational field is not the same as higher in a gravitational field] Nonetheless, the trouble you're having, which I've now said in 3 or 4 posts in a row, is that you don't understand that the word means the definition.

Yes, you did misread the quote, being so eager, as always, to correct me... only it wasn't me this time but another quote from "a respected scientific source," I presume.

 

Secondly, tho you will find this impossible to believe, I am not the one here having the trouble. (This will not compute for you, given your premise that I am always wrong and you are always right.)

Never the less, your phrase, "you don't understand that the word means the definition"... makes no sense."

Check this out:

You said,

"If time = the pace of a physical process (by definition) then there is no difference between these two statements

 

* Time is increased higher in a gravitational field.

* The pace of a physical process is increased in a higher gravitational field.

If time = the pace of a physical process (by definition) then there is no difference between these two statements

 

* Time is increased higher in a gravitational field.

* The pace of a physical process is increased in a higher gravitational field.

 

They are exactly equivalent. Yet, you agree with the second statement, but object to the first which makes no earthly sense to anyone who understands what a definition is.

 

What you don't understand is that ontologically "time" has become an entity that slows down and speeds up in the minds of the post-Einstein generation of physicists. It has been reified, as all my quotes and examples above illustrate. "It" has become a "thing" in the "training" of these young and authority-worshiping students of physics. "It" is no longer the sensible concept of "the pace of physical processes", which we agree changes pace under different conditions. "It" has been reified to the extent that sci-fi has become "reality" in the minds of, for instance, those who believe in "time travel."

 

"It" has become a "video" in the minds of the sci-fi gullible, and "it" (time) can be "fast forwarded" and "reversed/rewound" in the minds of folks who believe that "time is such a medium" that one, with the right futuristic equipment, of course, can "travel into the future and the past."

This misconception is one of the sources of my passion for debunking this reification of time. You can dismiss my objections, as above, but the problem, the misunderstanding of time, will not go away just because you have well expressed the equivalence of "time=the pace of a physical process"... with which I totally agree.

 

You are treating time as something different from "that which a clock measures" or "the rate of a physical process". You reify time yourself then object to its reification. You should really stop that.

 

I am sorry that you do not understand that a circular argument, the tautology of "Time is that which clocks measure" is no argument at all in the realm of ontological inquiry into the nature of "time."

 

If you throw out manufactured clocks, what is left is the natural existence and movement of *everything in the known cosmos."

There are no natural "time environments," one "going faster" and another "going slower" anywhere in the actual cosmos...

Everything moves "at its own natural pace" in the real cosmos, independently of human obsession with "measuring time!"

 

I must go. Not done yet but "present reality" in my personal life must trump this interesting discussion.

Later,

Michael

[Moontanman]

Time, what is time, I have watched this thread wind around and around from time is all there is to time doesn't exist at all. If you really want to experience time i suggest you get stuck in a six lane grid lock on a hot summer day, low on gas with a violent case of diarrhea. That my friends is the essence of time. It may not be a actual thing like a rock or a star but time passes and nothing marks that passage like the inevitable progression of an unpleasant cause and effect:evil:

[modest]

What you don't understand is that ontologically "time" has become an entity that slows down and speeds up in the minds of the post-Einstein generation of physicists. It has been reified, as all my quotes and examples above illustrate. "It" has become a "thing" in the "training" of these young and authority-worshiping students of physics. "It" is no longer the sensible concept of "the pace of physical processes", which we agree changes pace under different conditions. "It" has been reified to the extent that sci-fi has become "reality" in the minds of, for instance, those who believe in "time travel."

 

I think you’re seeing where I’m coming from.

 

It probably doesn’t make sense to you (or, at least, it shouldn’t) why Einstein would say this about relativity:

 

According to the general theory of relativity the four coordinates of the space-time continuum are entirely arbitrary choosable parameters, devoid of any independent physical meaning.

 

while you would say this about relativity:

 

...which is prior to relativity theory as assuming time's existence as an entity...

 

Einstein says, in so many words, that space and time are not physical entities. He claims that his theory of general relativity proves that space and time are not things that exist in and of themselves. You then claim that relativity assumes that time is an entity... a thing being reified by the theory. One of you is mischaracterizing relativity, and believe it or not, it’s not Einstein.

 

So, I’ll say just one more time... When you hear a popularization of science description of relativity saying something like “spacetime is a malleable medium being curved by mass”, you do best understanding that you are hearing an analogy—a metaphor. The theory itself, were you to invest in understanding it, has far more precise meaning and far more profound philosophical implications.

 

~modest

[allemory]

Time is how we get from 'what was' to 'what is'. I'm more interested in the divisions of time. That it passes is not in question...but HOW it passes. In our minds it can pass slowly (when sitting outside the principals office) or quickly (enjoying a drink with an old and dear friend). but however we thing of it...time marches on. Why 60 seconds in a minute...or 24 hours in a day? Why not 20. Arbitrary distinctions...perhaps. Time is subject to our perception...and as I grow older...it seems to be slipping away ever more quickly.

[Michael Mooney]

Modest:

Einstein says, in so many words, that space and time are not physical entities. He claims that his theory of general relativity proves that space and time are not things that exist in and of themselves. You then claim that relativity assumes that time is an entity... a thing being reified by the theory. One of you is mischaracterizing relativity, and believe it or not, it’s not Einstein.

 

So, I’ll say just one more time... When you hear a popularization of science description of relativity saying something like “spacetime is a malleable medium being curved by mass”, you do best understanding that you are hearing an analogy—a metaphor. The theory itself, were you to invest in understanding it, has far more precise meaning and far more profound philosophical implications.

 

So the following references are merely metaphorical?:

 

"Time goes more slowly in higher gravitational fields..."

It really means "physical processes go more slowly..."

(Yet the metabolism of men in a high G-force centrifuge does not slow down? Why is that?)

 

" Frame-dragging, (means that) a rotating mass "drags along" the space time around it."

Please tell me what it is, metaphorically speaking, that is dragged along by a rotating mass.

 

"According to Albert Einstein! Without gravity, space would be flat. Gravity actually curves, or "warps," space. The more dense the matter is, the more the space around it is curved."

 

How does metaphorical space take on a curved shape? ... and what does "flat space" or curved space mean anyway if space is just volume, not a malleable medium?

 

"The sun creates the curved structure of space-time, and the planets move on geodesics or "straight lines" in curved space-time."

 

What is metaphorical about this claim that planets actually move in straight lines in "curved space-time?" What is lacking here is a "straight" answer.

 

"According to The Theory of Relativity gravity bends space time around it. ... Actually light always follows a straight path,but its the space that bends."

 

Again, how is the above merely metaphorical space and space-time?

If "something" is said to "bend", other than the mind trying to grasp the metaphor,... what is that thing? Sure sounds like a description of a malleable medium to me.

 

What is the "glorious non-entity" in Harvey R Brown and Oliver Pooley's book, "Minkowski Space-time: A Glorious Non-entity?"

 

What do you suppose all the fuss is about at the International Conference on the Ontology of Spacetime...

Conference Program

 

...if spacetime is so well understood (cut and dried, so to speak) as you imply?

BTW, tho I have not read it, the "Contents" of Dennis Dieks' book THE ONTOLOGY OF SPACETIME, 1

The Ontology of Spacetime, 1 - Elsevier

looks like a deep study of the issues. I find the topic of "presentism and eternalism" in the "Description" section especially fascinating. I may have to acquire the book and read up!

Are you quite sure you have all the answers down pat, as you come across?

 

Just a few questions to contemplate. A few answers would be really nice for a change.

Michael

[Michael Mooney]

Hey CraigD,

Speaking of answers, I was really looking forward to yours in reply to my post 742 above.

Michael

[PerfectLiquid]

...

Einstein says, in so many words, that space and time are not physical entities. He claims that his theory of general relativity proves that space and time are not things that exist in and of themselves.

...

~modest

Hi Modest,

 

Since we're on the subject of Einstein, it may be of interest to consider some of the other ways that he viewed space-time:

1. From his presentation at the University of Leyden (1920): "According to the general theory of relativity, space without aether is unthinkable." In later work, Einstein used terms such as physical space, physical properties of space, or physical structure of space in place of this reference to aether.

2. “Space is the primary phenomena and matter is derived from it as a secondary result .” [A. Einstein, “The Concept of Space,” lecture delivered at the University of Nottingham, 6 June 1930, Einstein's Balckboard - School of Physics & Astronomy - The University of Nottingham As summarized by Kostro, , “he [Einstein] finally came to the conclusion that four-dimensional space (the space-time continuum) constitutes a reality ontologically primary even to matter.”

 

While these clips do not nail down his precise views on space-time, I think the second quote is instructive. If space-time was simply an abstraction that reflected the mathematical properties expressed in his equations, how can it be transformed into matter? While one could easily counter this point of view with a "Where's the proof?" query, it does raise a thought provoking question. How could something that is apparently as unstructured as space-time, lead to the formation of matter and the subsequent structured collections of matter like our own Milky Way? This is largely the same problem that dogs current views of the CMBR as representing remnants of the Big Bang. Without some form of preexisting structure / complexity (i.e., low entropy condition) in either case, there would seem to be a violation of the Second Law of Thermodynamics.

 

Regards,

Al

[modest]

Hi Modest

 

Howdy. Excellent reply PerfectLiquid. I'm afraid a combination of being short of time and the topic being, well, a bit off topic, will force my reply to be terse.

 

1. From his presentation at the University of Leyden (1920): "According to the general theory of relativity, space without aether is unthinkable."

 

Yes. In Einstein's time the term ether was much more readily accepted (more accepted than the term 'spacetime' for sure). He did his level best to adapt the common usage of ether to his field in GR. A couple links and quote I've given before:

 

Ether and the Theory of Relativity

 

Einstein in later years proposed calling empty space equipped with gravitational and electromagnetic fields the "ether", whereby, however, this word is not to denote a substance with its traditional attributes. Thus, in the "ether" there are to be no determinable points, and it is meaningless to speak of motion relative to the "ether." Such a use of the word "ether" is of course admissible, and when once it has been sanctioned by usage in this way, probably quite convenient.

 

http://www.tc.umn.edu/~janss011/pdf%20files/ether.pdf

 

The way Einstein used the term there is, of course, not the way it is used today. For this reason, I think using the term serves little more than mucking up the waters.

 

Nonetheless, I think you quite rightly bring it up.

 

“Space is the primary phenomena and matter is derived from it as a secondary result .” [A. Einstein, “The Concept of Space,” lecture delivered at the University of Nottingham, 6 June 1930,

 

While I don't know the context of this quote from the link you give, I do recognize the context from reading something previously:

 

http://adsabs.harvard.edu/full/1930JRASC..24..384.

 

It was certainly Newton who made space into something real. I wouldn't go as far as to say "physical", but something of consequence (something to be considered) for sure. Newton's problem was treating space as something absolute. Einstein demonstrated that it is meaningless to talk about space without reference to matter and meaningless to talk about matter without reference to space.

 

If we're to discuss this further, may I suggest you start a new thread.

 

~modest

[HydrogenBond]

The bending of space-time, by gravity, only has to do with the bending of the coordinate system or plot called space-time. If we drew a graph of space-time and bent the graph, we show the equations of matter near gravity.

 

Unless space and time are tangible things, there is no bending going on in reality. The bending is all on paper. There is a tendency to want the cake and eat it, at the same time, leading to confusion. Time and space are called reference variables for a plot, but they are treated like they are real things that can bend, creating confusion in the mind.

 

If we said we need to bend the space-time graph when we plot near a blackhole or we need to expand the space-time graph for the universe to simulate its expansion, it looks like a correlation. The confusion makes it seem more mystical, because the mind is not thinking only equations but actual physical changes.

 

A simple circular orbit now looks like space-time is bending, when all we are doing is making our graph into a circle to plot an orbit. We call it curved space-time on one hand, while also saying these are not real things. If we use one or the other and not both at the same time, it leads to other visualizations.

 

For example, say we get rid of the term space-time bending, since we can't bend something that is not physically real. Space-time is not really bending, just the path of the object is following a curve. This is what Newton saw. If we make space-time tangible, they have the properties of physical laws. Now an object sees differences in distance and time potential, as a function of path, accounting for motion and behavior. If we have our cake and eat it at the same time, it looks like something is bending that is not even considered tangible; paradox for a mystical special effect.

[PerfectLiquid]

Hi Modest,

 

I think you're right about branching off into a new thread. Since I'm a novice here, does "Space-time and Relativity" make sense? Thanks.

 

Regards,

Al

[Michael Mooney]

Re post 759:

Thanks, HB.

This is the clearest post I've read yet in this forum addressing the ontology of "spacetime" ...

Like what I was driving at (without your clarity of explanation) all those months in my "spacetime" thread.

Lots of folks have referred to it as a "metric" for the math of relativity, but from the git-go it is always referred to as a malleable medium, an existing entity.

For instance Tormod right off the bat (post#2) posted as follows:

 

Nobody really knows what "spacetime" is (just as we have no good explanation of what exactly "time" is). We do however know a few things about how it behaves. On quantum levels, spacetime has different properties than on macroscopic levels. This much is known because of studies in fundamental particle physics (for example in the particle colliders).

 

Spacetime isn't an attempt to "create something where there is nothing". Rather it is an attempt at explaining what there *is* that comprises the space between "things" in the cosmos.

 

That objects bend the paths of light traveling through space was proven back in 1919. The only apparent explanation for this (since light is a massless particle) is that light travels "through" something. Since the aether had been disproved there was no need to add a cosmic "fluid".

 

There was however a need to unite space and time since it was apparent that light traveled through space, and that the speed of light was finite (another of Einstein's insights). Thus the way light shifts when it passes around an object can be used to measure the gravitational pull of that object. In relativity theory, gravitational pull is actually a distortion of spacetime. Spacetime is, however, four dimensional, and therefore the "sheet with holes" is used to simplify and make it possible to understand the concept.

http://hypography.com/forums/philosophy-of-science/17037-what-is-spacetime-really.html

 

If Tormod had not continued in the long tradition of spacetime reification in the first place (as above), the locked thread would have been short and sweet.

 

Again thanks for the clarification.

Michael

PS, I have never understood the mind-set which insists that space must be "something" (as in the assumption "that light travels "through" something") besides empty volume.

[RCP/CRT/RRT]

I'm gonna have to admit it is rather mind bending.

 

Malleable, but not tangible. Real, but not physical.

 

A foaming, expanding, finite, but unbound sea of un-nothingness... Oh, I get it :)

 

 

 

(edit: this is in regards to the spacetime discussion generated, not necessarily time)

[modest]

Hi Modest,

 

I think you're right about branching off into a new thread. Since I'm a novice here, does "Space-time and Relativity" make sense? Thanks.

 

Regards,

Al

 

Yes, that would be good—in the Philosophy of Science forum. :)

 

~modest

[AnssiH]

That is why I asked about your philosophy as per possibly a version of Kant's transcendental idealism.

 

You could say that, depending on how you understand Kant. I have certainly used the concept of noumena many times before.

 

It still seems to me that you think one version of 'what we think we know about the world/cosmos' is as good as another (if it is internally consistent and coherent) since it is all about perceived patterns, which all depends on our equipment and perspective of perception.

 

Any version that fits the accumulated data is as good as another, obviously. After all, "it fits all the accumulated data" :) They are all just different versions of "all that we know".

 

This issue is not about what equipment we use to gain the data, it's about the possibility of creating numerous explanations for any set of data.

 

The arguments over which "version of the truth" is correct are just arguments over semantics. By definition, there is no information to tell you which version is better than another.

 

Think about Plato's allegory of the cave. Prisoners - who don't know anything about reality - see shadows on the wall, and try to guess what is causing the shadows. It is not important whether each prisoner has got "ontologically valid" idea about what exists "out there". Each prisoner may have a radically different fantasy in their head about what the shadows "are" and where they are coming from. Each ontological fantasy, if it explains all the past shadows so far, is just as undefendable as others. What is important is that their idea - wrong as it may be - yields good predictions about the shadows.

 

That is exactly the situation we are facing regarding our musings about reality. You don't know what anything is, until you've come to tack some specific meaning to some specific data pattern. Only then, your version of the truth may refer to some features of the ongoing stream of data as "a stone in my hand". It makes absolutely no difference whether your version is somehow ontologically valid. What is important is that the future of the data can be in some meaningful way predicted. That ability has got nothing to do with whether that "stone" has got any sort of ontological identity to itself.

 

Or whether there ever is any sort of ontological validity to the identification of any elements, when each identification is entirely based on recognizing familiar patterns. Note that ANY given version, when taken as an ontological argument, is taking the undefendable position that some portions of reality are ontologically "objects" (i.e. they are "things in themselves" persistently through time).

 

Now I know that in your version of the truth, you very much want to see euclidean space and dynamic time w/ universal simultaneity as ontological truths. But think first about the fact that, to get to any meaning for "space", you have to define some elements, that in your version of the truth hold persistent identity through time, and are thus "in motion". Once you have bunch of elements in motion, it is their behaviour that defines what you mean by "space".

 

Dropping out the ontological fantasies and semantical arguments, and talking about this entirely through epistemological consequences, we can say that euclidean space and universal simultaneity are consequences of having defined persistent elements (out of unknown patterns) in such way that they obey newtonian laws. Those elements, that obey newtonian laws, give meaning to "space". But that "space" is still an idea, just like "up" and "down", in that it's an idea that gets its meaning entirely from other defined things in our head, and in the absence of those definitions, we cannot put any ontological validity to its existence. No matter how many times you throw a stone "up" and watch it fall "down", you are still observing only your version of reality.

 

Ontologically speaking, no one told you reality is like that. Epistemologically speaking, there are very good reasons - having to do with prediction abilities - that would make you define reality that way.

 

What you can pick up from this is that there are certainly many different ways to define "space" and "time". One of which is relativistic spacetime. That is still an ontological fantasy just as much as any other, and it does certainly bother me that people tend take it way too seriously. Even physicists who say they don't suppose any ontological validity to it, tend to make further arguments that can be valid only if that ontological interpretation is valid (i.e. "time begun at big bang" or "causality will break if information moves faster than c" or "it is possible to create spacetime wormholes to move through time" etc,etc,etc). So I think you are right to complain about that fact.

 

I think part of the reason why Minkowski's idea about spacetime became so popular was that it offered a very simple picture about "relativistic simultaneity". I think most people did take that as an ontological explanation of that particularly odd feature of relativity, and I think Minkowski's own comments imply he did also.

 

Such arrogance and elitism does nothing to further the dialogue on this subject. And you really don't want to pursue the assumption that I'm just to stupid to understand... which is how I read you.

 

I'm afraid it's the kinds of arguments that we are seeing in this thread that is not furthering the dialogue on this subject, because it is just impossible to even understand what does someone mean when they say "time" or "spacetime" or use all kinds of poetic ways to explain what time is "in their opinion". It really does require quite a bit more analytical approach.

 

I guess it is fair to say, that you are interested of arguing the reasons why relativistic time relationships are valid, i.e. what does their validity imply about ontological reality. Now, that is interesting question, but here it seems to come down to arguments about each personal fantasy very quickly, and I feel people are just to busy explaining their perspective, and too convinced that no one else can understand the issue quite like they do, that they never come to think about the explicit, epistemological reasons behind the validity of relativistic description. (it is most certainly not a trivial issue that could be explained in any brief manner)

 

I can also tell you that, if you take more analytical approach, you can find that your explanation, that it's the acceleration effect that slows down physical processes, will not yield a valid explanation to the so-called time dilation observation. At least not without much more definitions to it. I think if you had worked out a valid view like that, you would have those definitions and you would have given them by now.

 

Let it be said that I would certainly not say "time dilation = the change of pace of an actual physical process with relative velocity", as I don't think it's a good idea to imply a "change of pace of an actual physical process" occurring simply due to changing your perspective on how you are looking at that physical process. Epistemologically speaking, one should be asking, why is it that we have to perform relativistic transformation when choosing different coordinate systems to plot the same data in. Epistemologically speaking, the exact explanation as to why that is so already exists. You have to understand that it has to do with how any dynamics or "change" can have any meaning at all, as they are defined in our head. I.e. From the point of view of defining persistent elements in "prediction-wise"-valid manner. Understanding all the steps to relativistic time relationships requires as much analytical thinking ability, as walking through any involved physical explanation. A lot more than most people are ready to put into it here, I'm afraid. But I think Bombadil is very close to getting it.

 

Ooops, sorry about the length.

 

-Anssi

[Little Bang]

Anss, could it be said that there is a possibility the standard model fits in with your post above?