Is Time Absolute or Relative: Bob Enyart argues it's absolute...

[Clete]

Can someone tell me in 500 words or less how ThePhy's post addresses the actual point of Bob's post?

I gave up after about read two thirds of his post and the summary. Of what I read, it seems to me like one gigantic red herring. I give high marks for good writing and an interesting essay on the measurement of what we call time but it never addressed the issue that Bob brought up. Instead he made the same error that Taoist made by introducing irrelevant details that have nothing to do with the question, only he took the introduction of irrelevancies to a whole new level. He didn't introduce a red herring but rather a whole school of them.

The simple fact is, that it doesn't matter what a second is or how imperfect a clock the Earth's rotational period turns out to be (I love puns ). Just because you take a detail or two that was brought up in the opening post and run off onto four hundred rabbit trails based on that detail doesn't mean you've addressed anything that the opening post was about. All you've done is removed those detail from the context of the post and started a whole new discussion on those individual topics and ignored the topic you are supposedly responding too. If the discussion of these topics were ever related directly to the point of Bob's post is definitely missed it. If I have missed it and someone could simply point out to me where ThePhy has addressed the following point that I made in post #92, then I would be happy to respond to that specific point.

The only thing getting out of sync is our clocks, not us, and not the sun or the Earth or anything else, just the clocks. If I were actually getting out of sync with you along with my clock then if the sunset was supposed to happen at 8:33pm then when your clock read 8:33pm the sun would be setting for you and then later when my clock read 8:33pm the sun would be setting for me. But that isn't what happens. I watch the sunset at the exact same moment that you do, in spite of the fact that my clock says it shouldn't happen for several more hours. Thus it isn't time itself that has been effected but merely our clocks.

I don't think ThePhy addressed this point at all and since that is the main point of the discussion then I would say that while he is obviously an intelligent guy and a good writer, his essay has been a waste of time, relatively speaking of course.

Resting in Him,
Clete

 

[temple2006]

Clete...Can't you understand that gravity affects more than clocks?

 

[Clete]

Clete...Can't you understand that gravity affects more than clocks?

Of course it does. But it does not effect time, that's the point. Do you have an argument that would refute the logic in Bob's openning post or in my post #92, or not?

 

[SUTG]

Of course it does. But it does not effect time, that's the point. Do you have an argument that would refute the logic in Bob's openning post or in my post #92, or not?

Not all observers agree that it takes 24 hours for the earth to orbit the sun. And they are all correct. Therefore, absolute time does not exist. :cheers:

 

[taoist]

"Clete, really! This is appalling ignorance.

You need to sit down with an elementary physics book. People separated in space-time most certainly do NOT experience the same moment. They cannot, as the speed of light gets in the way.

There's a thing called interval you need to study.

Wander away from me a light-second and turn on a lamp. One second later, I'll turn on my own. To me, the two lights will appear simultaneous, even though to you, they are separated by two seconds.

Think about it."

You are introducing irrelevant variables. One must account for the time it takes for the light to travel to me and whatever other variable may change my perception but in the end you turned on your light at a particular moment and at that moment I was doing whatever I was doing and we were both present at that moment in time together.

Excuse me, Clete, I didn't until just now see you had posted this response.

The "variable" I'm introducing is "the existence of separate frames of reference at the heart of both general and special relativity." As such, in a discussion of relativity, it is absolutely relevant, by definition.

At its heart, relativity denies the very concept of simultaneity for "events" separated in space-time. In particular, this includes those events separated exclusively in the spatial dimensions whether the separation is one mile or one light-second, and whether the separation occurs in a "flat" or "curved" region of space-time. It was the similarity between these separations I attempted to introduce in my previous, admittedly impolite, post, and, by extension, the need to consider frames of reference when discussing either special or general relativity.

Again, I apologize for my needless abrasiveness.

Still, I ask you to realize that the "moment in time" we share is an illusion. We are not able to agree even on as simple a thing as what "moment in time" we each turned on our lights. You say it was two seconds ago, I say it was simultaneous. Were time absolute, one of us would have to be wrong! Giving us separate frames of reference has the distinct advantage of not having to fight over who should be called a liar.

:chuckle:

This is why Bob's illustration is so brilliant. You have two people who are on the same planet with one another and yet are supposedly experiencing time dilation effects relative to each other because of the difference in the pull of gravity in one location relative to the other.

I've split your paragraph here in the interest of isolating the position where your argument becomes difficult to follow.

Because special relativity is easier to understand, I expressed my example in terms of events separated in an "uncurved" region of space-time amenable to special relativity. To construct a similar example directly linked to the gravitational effects in Bob's example, one in which his "day" would be comprehensible to an observer limited to experience on the scale of a human lifespan, it would be necessary to move his example to the near vicinity of a black hole, an area where our intuitive grasp of conditions is far less stable, but also an area where the true alien nature of the separate frames of reference becomes noticeable.

Bob's example hides this alien nature by extending a human lifespan across millions of years in order to simulate an intuitive grasp that does not actually exist. Millions of years of personal experience really is as foreign to our understanding as life in a black hole.

It still works because according to Relativity, gravity is nothing more than an acceleration along curves in the "fabric of space-time" thus when you are in a gravitational field, you are, in effect, traveling along that curve and if someone's gravitational pull is different that means their acceleration along that curve is different and so their time dilation is accordingly altered. (Is this elementary enough for you?).

"It still works" uses a preposition without a referent I can follow and thus I'm not able to understand what conclusion you hope to support with this sentence.

Turning to your "because" clause, you say that "gravity ... is an acceleration along curves in the fabric of space-time."

This varies widely from the theory and takes some work to unravel. Gravity is, in general relativity, the cause for curvature in space-time, not an acceleration along curves implying the movement of some object.
'
Given a path in space-time, travel along it cannot properly be described in terms of acceleration. Acceleration is a change in spatial velocity over time, where velocity is a change in spatial position over time. I've drawn out these definitions to focus on the meaning of space-time itself.

Now to unravel the fabric, we need to move slowly.

***

What is the "fabric" of space-time? It is the set of 4-dimensional positions in space-time called "events." Similar to the separation of points in space we call distance, there is a separation of events in space-time called "interval." This interval incorporates distance in space, which I'll call spacedistance to differentiate it from distance in time, which I'll call timedistance. Using nothing more than the standard Pythagorean theorem, interval can now be readily described.

Interval is the squareroot of (squared spacedistance + squared timedistance)

Notice that for contemporary events, interval is just normal distance.

In order to calculate interval it's necessary to match units of time to units of distance. This is done by multiplication of a fundamental constant linking distance and time. This fundamental constant is called "c", the speed of light, and the formula for separation in spacetime reflects this.

Spacedistance is given by "ict", where i is the squareroot of negative one, c is the speed of light and t is the separation of events in time. Note that squared timedistance is negative. Thus, from my frame of reference, lighting your lamp one second ago in time cancels out your one lightsecond of distance, so the interval between where-when I see your lamp and my own is zero.

***

With the above concepts in mind, consider "acceleration in spacetime". Acceleration occurs in space (not space-time) over time. Space-time, as a representation, incorporates time as part of its structure. It simply doesn't make sense to ask how fast we can cover an "interval." Geometrically, one needs to "project" events out of spacetime into space in order to speak of acceleration.

You can "project" your three dimensional self by standing in the sunshine and allowing a shadow to fall onto a two-dimensional sidewalk, thus eliminating your height. Here we come to the nub. Similarly, you can "project" the set of 4-dimensional events in spacetime that form your life by "falling" into a reference frame, thus eliminating your extended existence across time.

***

Thus, acceleration in spacetime is inherently without meaning. Standing on this misperceived foundation, you continue, but I see no reason to follow until you've recovered your footing. With this in mind, perhaps you'd consider attempting to rephrase your "elementary" description of gravity's relationship to the general theory of relativity.

The point here is that we don't have to introduce the complicating factors of having to calculate and account for the time it takes light to travel to the observer because they are on the same planet and that time is negligible.

My point is, that to discuss the consequences of the general theory of relativity, it is necessary to have a basic understanding of the general theory of relativity, an understanding I'm sure lies within your grasp should you decide to make the effort.

In particular, it is necessary to understand how separate frames of reference are fundamental to the theory and how they lead naturally to the definition of space-time itself, created to provide a place for frame-invariant descriptions. In the process, one discovers a previously unlooked for understanding of time, so wonderfully addressed by ThePhy's recent post.

So could we concentrate on the illustration we have been given and stop with all the red herring distraction techniques. You guys are stumped on this one, and I am not going to let you change the subject so as to make yourselves feel better.

Resting in Him,
Clete

Again I urge you to spend a few hours with a standard physics book that covers the theory, do a few of the sample problems and reconsider your positions about both the definition and absolute nature of time. There is a clarifying effect that occurs only when the hand-waving ends and the numbers have to go into the calculator. This, to a scientist, is where the rubber meets the road.

Until you make this effort, unfortunately, you will be "stumping" your readers with an excursion into physical fantasyland.

In peace, Jesse



(I invite Johnny or ThePhy to correct any glaring errors in this presentation. I haven't done any study in this in beaucoup years. I'm basing most of this on the n-space realms with which I'm more familiar.)

 

[taoist]

Clete,
The only thing getting out of sync is our clocks, not us, and not the sun or the Earth or anything else, just the clocks. If I were actually getting out of sync with you along with my clock then if the sunset was supposed to happen at 8:33pm then when your clock read 8:33pm the sun would be setting for you and then later when my clock read 8:33pm the sun would be setting for me. But that isn't what happens. I watch the sunset at the exact same moment that you do, in spite of the fact that my clock says it shouldn't happen for several more hours. Thus it isn't time itself that has been effected but merely our clocks.


taoist,
To address this properly we need to insert an observer next to each of these clocks, it seems. So let us do so. I nominate a pair of identical twin men. However, neither gets to bring a shaving kit. The test will be, who, if either, grows the longer beard.

While I can't see any way to collect on this one, I got a finsky on the outcome if anybody cares to take me up on it.

 

[ThePhy]

A Propitious Moment

A Propitious Moment

From Clete:

If I were actually getting out of sync with you along with my clock then if the sunset was supposed to happen at 8:33pm then when your clock read 8:33pm the sun would be setting for you and then later when my clock read 8:33pm the sun would be setting for me. But that isn't what happens. I watch the sunset at the exact same moment that you do, in spite of the fact that my clock says it shouldn't happen for several more hours. Thus it isn't time itself that has been effected but merely our clocks.

What do you mean by “supposed to happen at 8:33pm”? If we are in our daily world that we are familiar with, I think we would agree that we might expect sunset at 8:33. But if I am a competent scientist, and I know I am going to spend some time in a place where gravity is significantly different than the normal we are used to, I will not expect sunset at 8:33 (on my clock). I will expect it sometime earlier. And you and I will see the sunset at the same moment. It is just that both I and my clock will have felt the passage of less time than you and your clock have since we parted. So ours clocks will not assign the same timestamp to the moment of sunset. (And less than 500 words)

 

[Clete]

Taoist,

While I appreciate your more polite tone I still think you are missing the point, although I'm convinced that you are not doing so intentionally. Let me try again to explain.

When I say that the points you are raising are irrelevant, I do not mean to suggest that they are irrelevant to Relativity but rather that they are irrelevant to the thought experiment that Bob has presented in post 1 of this thread. They are irrelevant because all of the variables you are bringing up effect both clocks (and both observers as well, which I had already been under the assumption were included in the scenario anyway. What good is a clock with no one to read it?), and therefore are of no benefit in attempting to account for the extra day that one clock has recorded relative to the other.

In effect just wipe out all of those variables by assuming they are all equal on both sides of the equation. Assume that all other things are equal except for the gravitational field intensity and the results will come out as Bob has suggested and yet even though one clock will eventually be noticeably out of sync with the other, the Sun will still set and will have set at the same moment for both observers every day for the entire duration of the experiment, even though one of those observers clocks says that the Sun should be setting for another several hours yet.

Resting in Him,
Clete

P.S. While I do not under any circumstances consider myself to be an expert in the field of physics, I am not new comer to the subject either. It was my major while in college until I figured out that I was more interested in philosophy and drop it. So I'd really love it if you could stop it with the insulting "sit down with a basic physics book" nonsense.
Thanks.

 

[ThePhy]

Trusting the peanut gallery

Trusting the peanut gallery

Taoist, when I said: “Second best – ask me. Trust me" I was playing into the recognition that Bob sometimes ridicules opponents for appeals to authority – or what he terms “Trust me”. I didn’t want him to have to search hard to claim I used a “Trust me” approach.

 

[simply one]

ThePhy's Post

ThePhy's Post

ThePhy,

Thank you for taking the time to provide us with a post by someone who actually understands the scientific principles of Time. I myself was posting mostly based on vague assumptions which i ahd learned from an assortment of books. That post was most helpful.

I cannot believe that Clete brushed off the post as irrelevant. It is a strategy that I have seen used too many times by many of the more right-leaning TOLers. They simply brush something off as completely irrelevant, without even taking the time to read the entire post or to actually consider the concepts involved.

But, basically, thank you ThePhy.

 

[Clete]

From Clete: What do you mean by “supposed to happen at 8:33pm”? If we are in our daily world that we are familiar with, I think we would agree that we might expect sunset at 8:33. But if I am a competent scientist, and I know I am going to spend some time in a place where gravity is significantly different than the normal we are used to, I will not expect sunset at 8:33 (on my clock). I will expect it sometime earlier. And you and I will see the sunset at the same moment. It is just that both I and my clock will have felt the passage of less time than you and your clock have since we parted. So ours clocks will not assign the same timestamp to the moment of sunset. (And less than 500 words)

Finally! Someone at least attempted to address this point! Thank you!

The gravitational field intencity does not have to be "significantly different" all it has to be is different. If the effects of Relativity are slight then it would take a longer period of time for the difference to be noticable but that's why we have our experiment going on over a very, very long period of time.
Further, if (again assuming all other variables like longitude and horizon distance etc are accounted for or simply assumed to be the same for both parties) the Sun was supposed to set at 8:33pm Eastern Standard time (it's really sort of silly that I have to be so particular with these sorts of detail) then if the clocks are moving through time at the same rate each of the clocks observers are (which again is a variable that we are assuming to be the case) then when your clock read 8:33pm EST then the Sun should be setting for you (and would be if Einstein was right) and when my clock read 8:33pm EST the Sun would be setting for me (again, assuming Einstein was right). But that is not what would happen! If you after watching your sunset could instantly beam youself over to me and my clock, you would observe that the Sun had just set for me just as it had for you in spite of the fact that my clock reports that it is 3:25 in the morning.

Resting in Him,
Clete

 

[Clete]

ThePhy,

Thank you for taking the time to provide us with a post by someone who actually understands the scientific principles of Time. I myself was posting mostly based on vague assumptions which i ahd learned from an assortment of books. That post was most helpful.

I cannot believe that Clete brushed off the post as irrelevant. It is a strategy that I have seen used too many times by many of the more right-leaning TOLers. They simply brush something off as completely irrelevant, without even taking the time to read the entire post or to actually consider the concepts involved.

But, basically, thank you ThePhy.

This is a lie simple one. I have not simply "brushed it off as irrelivent". I have instead explained why it is irrelivent and asked repeatedly for someone to show me how it is relevent if I am some how missing something. The only strategy involved is one that attempts to get people to show me where I am wrong. Can you do that? If not, then you need to shut your little lying mouth and keep your opinions about other people's motives to yourself.

Resting in Him,
Clete

 

[taoist]

Taoist,

While I appreciate your more polite tone I still think you are missing the point, although I'm convinced that you are not doing so intentionally. Let me try again to explain.

When I say that the points you are raising are irrelevant, I do not mean to suggest that they are irrelevant to Relativity but rather that they are irrelevant to the thought experiment that Bob has presented in post 1 of this thread. They are irrelevant because all of the variables you are bringing up effect both clocks (and both observers as well, which I had already been under the assumption were included in the scenario anyway. What good is a clock with no one to read it?), and therefore are of no benefit in attempting to account for the extra day that one clock has recorded relative to the other.

In effect just wipe out all of those variables by assuming they are all equal on both sides of the equation. Assume that all other things are equal except for the gravitational field intensity and the results will come out as Bob has suggested and yet even though one clock will eventually be noticeably out of sync with the other, the Sun will still set and will have set at the same moment for both observers every day for the entire duration of the experiment, even though one of those observers clocks says that the Sun should be setting for another several hours yet.

Resting in Him,
Clete

Thanks.

Good then,

Let's let our clocks be tended by John and Jake Occam. They have between them just the one Razor, actually belonging to their father William, who shaved his twin sons before setting them their clocktending tasks. It is my assertion that John, carried down the mountain by helicopter, will be sporting the longer beard when they meet again.

When William sees this, his Razor will insist that they must somehow have spent their time in relatively different ways.

In peace, Jesse

P.S. While I do not under any circumstances consider myself to be an expert in the field of physics, I am not new comer to the subject either. It was my major while in college until I figured out that I was more interested in philosophy and drop it. So I'd really love it if you could stop it with the insulting "sit down with a basic physics book" nonsense.

pps. If I could find a more palatable way of saying this, I would. Let me add that I've always found that running the numbers, or whatever it is I'm using as if they were "numbers", is always the best way to resolve paradoxes I think I've seen. I feel strongly this method should work for anyone.

But, after multiple unsuccessful attemps, as I can't see a way to express this without causing offense, I will, of course, avoid the suggestion in future. After all, this is supposed to be fun!

Best, Jesse

 

[Clete]

Good then,

Let's let our clocks be tended by John and Jake Occam. They have between them just the one Razor, actually belonging to their father William, who shaved his twin sons before setting them their clocktending tasks. It is my assertion that John, carried down the mountain by helicopter, will be sporting the longer beard when they meet again.

When William sees this, his Razor will insist that they must somehow have spent their time in relatively different ways.

In peace, Jesse

How does introducing another set of clocks help resolve the issue?

 

[taoist]

... I and my clock will have felt the passage of less time than you and your clock have since we parted ...

ThePhy, is it possible you've made the same mistake I just made (and corrected quickly) ... the natural thought for those of us who've run the numbers is that we'll be heading into a stronger gravitational field (as we'll never live long enough to note the difference in a weaker one) and so of course we'll seem to have aged less when we return.

But Bob's example is an excursion to a weaker field. Hence, more time will have passed for you, no? Or am I the one clinging to a sign error?

 

[Clete]

ThePhy, is it possible you've made the same mistake I just made (and corrected quickly) ... the natural thought for those of us who've run the numbers is that we'll be heading into a stronger gravitational field (as we'll never live long enough to note the difference in a weaker one) and so of course we'll seem to have aged less when we return.

We'll SEEM TO have aged less, or we'll actually have aged less? Are you sure you meant to use the term "seem" here? Because Einstein would not have approved.

Resting in Him,
Clete

 

[fool]

How does introducing another set of clocks help resolve the issue?

Exactly Clete, how does it.?:think:
Since Bobs' OP is based on an apparent discrepency between atomic clocks and sunrise/sunset counts I wonder if another set, or several other sets of clocks might be useful.

 

[taoist]

How does introducing another set of clocks help resolve the issue?

Hmm, I think we need to re-introduce Bob's premise ...

Two atomic clocks have been running for billions of years, one at the base of a mountain tended by Jake, and the other at the summit tended by John, sitting inside of a well-maintained Chinook cargo helicopter. The clock on the peak has been running faster by a few nanoseconds per year, but over the eons, it has advanced to twenty-four hours ahead of the clock far below, and it’s readout, in year, month, day, hour, minute, second, and nanosecond, is just now turning over to indicate exactly twenty-four hours ahead of the other clock, on a Friday at exactly high noon.

I didn't add any clocks, Clete, I added clocktenders. And my assertion is that John will have an extra day's growth of beard in comparison to his twin brother. As would any of their relatives.

 

[taoist]

We'll SEEM TO have aged less, or we'll actually have aged less? Are you sure you meant to use the term "seem" here? Because Einstein would not have approved.

Resting in Him,
Clete

ThePhy's beard says more time has passed than my beard seems to believe. This, of course, will seem unlikely to my beard as I hand him a beer. But rather than cause an argument, I suggest he buy the next round and we forget about it.

:cheers:

Of course, since I'm buying the first round, there'll be one for you too. Don't thank me, I stole all three from BillyBob's possum.

 

[Clete]

Hmm, I think we need to re-introduce Bob's premise ...

I didn't add any clocks, Clete, I added clocktenders. And my assertion is that John will have an extra day's growth of beard in comparison to his twin brother. As would any of their relatives.

Beard growth is nothing but another clock Taoist. All you've done is add another clock, a biological one to be sure, but a clock nonetheless.