about Bob's article on absolute or relative time

[Johnny]

I find it much more reasonable to assume that gravity is affecting the physical attributes of the instruments we are reading than to assume space is "curved".

There is no "effecting the physical attributes of the instruments" without some mechanism by which gravity exerts its effects. And that's what general relativity was put forth to explain. General relativity wasn't put forth to prove or even explain time dilation. It was put forth as a new understanding of gravity. How does gravity reach out and grab you and your instruments? At what speed does gravity act? Einstein answered all these questions with his theory of general relativity. The time dilating affects of general relativity are only a consequence, and a prediction, of the curved space explanation for gravity.

This explanation of gravity has been tested in a number of different ways. The first test was showing that massless photons traveled in curved lines around the sun. Since that time, numerous experiments and observations of ever increasing accuracy have confirmed general relativity. Everything from gravitational lensing, to frame dragging, to Mercury's perihelion shift, to time dilation, have all served to confirm Einstein's picture of gravity.

Can you tell me how my assumption will not cater for exactly the same reliability in mathematical calculations?

Absolutely -- your assumption undermines the entire premise of the mathematics. You assume that gravity's time dilating effect is only the results of gravity effecting the instruments rather than because of the curvature of spacetime. But you fail to recognize that the equations show that the way gravity interacts with instruments in any way would be through the curvature of spacetime! There is no having it any other way. That would be like using hydrodynamic equations to predict how water flow through city sewers will effect rain run-off, all the while claiming that water doesn't actually flow through city sewers! How does that make any sense?

 

[pozzolane]

There is no "effecting the physical attributes of the instruments" without some mechanism by which gravity exerts its effects. And that's what general relativity was put forth to explain. General relativity wasn't put forth to prove or even explain time dilation. It was put forth as a new understanding of gravity. How does gravity reach out and grab you and your instruments? At what speed does gravity act? Einstein answered all these questions with his theory of general relativity. The time dilating affects of general relativity are only a consequence, and a prediction, of the curved space explanation for gravity.

This explanation of gravity has been tested in a number of different ways. The first test was showing that massless photons traveled in curved lines around the sun. Since that time, numerous experiments and observations of ever increasing accuracy have confirmed general relativity. Everything from gravitational lensing, to frame dragging, to Mercury's perihelion shift, to time dilation, have all served to confirm Einstein's picture of gravity.

Absolutely -- your assumption undermines the entire premise of the mathematics. You assume that gravity's time dilating effects is only gravity effecting the instruments, not because of curved spacetime, but you fail to recognize that the equations show that the way gravity interacts with instruments in any way would be through the curvature of spacetime! There is no having it any other way. That would be like using hydrodynamic equations to predict how water flow through city sewers will effect rain run-off, all the while claiming that water doesn't actually flow through city sewers! How does that make any sense?

This is a very good response. And in a moment when and if Stripe and LH come back to reply, you'll see why I no longer bother discussing scientific topics with them.

 

[pozzolane]

You are, of course, entirely correct. It is a shame that more time is not spent in high school explaining precisely what a scientific theory fundamentally is. A scientific theory is a model that makes predictions - it is thus a description that tries to order and make sense of myriads of specific observations about the real world out there.

General (and special) relativity are precisely this - models of the real world "out there" (or at least models of "part" of it). And these models make specific predictions about what is expected to happen in a certain experiment if the theory is correct.

Yes, I agree. Though I must admit that I too was completely ignorant of the scientific process until I hit (about) my 3rd or 4th year in my undergrad program as an engineer. Now as a grad student, of course, I am well versed in the understanding and philosophy of the scientific method. Not trying to gasconade, In fact quite the opposite. However, I also was humble enough back then not to attempt to speak with authority on topics I new barely anything about. And I find that the more I learn, the more aware I become of how ignorant I really am.

I may seem like I'm being a jerk to LH and Stripe, but I've tried having these sorts of discussions before with Stripe, on a topic near my professional expertise no less, that only resulted in extreme vitrol. Stripe, I'm certain, is incapable of anything but asserting his own opinion based on his narrow point of view.

I'm also certain I exposed him lying about having an earth sciences degree. We argued about an earth sciences related topic and he clearly expressed to me (someone who knows and understands the verbiage) that he knew nothing of what he was talking about.

 

[Stripe]

...you fail to recognize that the equations show that the way gravity interacts with instruments in any way would be through the curvature of spacetime! There is no having it any other way.

Rubbish. Gravity interacts with instruments directly. We know this. We can test this. And the fact that we do not understand how it works is the perfect excuse to leave the assumptions at that.

You didn't answer my question. If we assume that gravity is affecting a clock (instead of relativity affecting the clock) how will that in any way limit our ability to use the measurements we make to arrive at the same calculated predictions?

That would be like using hydrodynamic equations to predict how water flow through city sewers will effect rain run-off, all the while claiming that water doesn't actually flow through city sewers! How does that make any sense?

Your analogy doesn't make any distinction between our standpoints. I'm claiming that gravity affects the readings we see. How is that any different from claiming that relativity directs the readings. I'm not claiming that water doesn't actually flow through city sewers". I'm simply blaming gravity for it's flow rather than the curvature of space.

Which do you think is responsible for run off?

 

[Stripe]

Here's the math from a simplistic and imaginary experiment:

Two synchronised clocks are set up. One flies around on a satellite. One sits on Earth.After ten years the satellite is brought back to Earth and shows a whole second of difference.

Then another satellite is sent into space and programmed to perform a number of actions.

Assuming relativity affected the clock means we can create an equation to calculate the timing of the actions on the satellite.

Assuming gravity affected the clock we can do the same thing.

Both assumptions use exactly the same numbers in every case.

 

[pozzolane]

Here's the math from a simplistic and imaginary experiment:

Two synchronised clocks are set up. One flies around on a satellite. One sits on Earth.After ten years the satellite is brought back to Earth and shows a whole second of difference.

Then another satellite is sent into space and programmed to perform a number of actions.

Assuming relativity affected the clock means we can create an equation to calculate the timing of the actions on the satellite.

Assuming gravity affected the clock we can do the same thing.

Both assumptions use exactly the same numbers in every case.

Translation: I haven't understood, nor even attempted to understand, a single thing Johnny has said and explained.

Johnny, seriously, don't waste your time.

 

[Johnny]

Here's the math from a simplistic and imaginary experiment:

Funny, you said "here's the math", but I didn't see any math whatsoever.

Two synchronised clocks are set up. One flies around on a satellite. One sits on Earth.After ten years the satellite is brought back to Earth and shows a whole second of difference.

Then another satellite is sent into space and programmed to perform a number of actions.

Assuming relativity affected the clock means we can create an equation to calculate the timing of the actions on the satellite.

Assuming gravity affected the clock we can do the same thing.

Both assumptions use exactly the same numbers in every case.

First of all, for the second or third time, you can't use current models of gravity without including general relativity. You can't even invoke gravity acting on the clock, at all, without incorporating a relativistic picture OR discarding the entire modern theory of gravity in favor of some pre-enlightenment ignorance where gravity is this mysterious phenomena we can't explain. Sure, we could take blind stabs at adding a correction factor for each altitude at each velocity at each altitude, poking around in the dark, bumping into large corners, never really knowing whats going on or why the our clocks keep "malfunctioning" (all by the same factor, an important point you keep overlooking), and wasting a lot of time and money in the process.

Or we could turn on the light and use the theory that explains whats going on, preempt those corners, understand why our clocks are behaving the way they are, correct them before they're even in orbit, and to boot have a coherent theory of electrodynamics with a solid mathematical foundation which is derived from well accepted and tested equations, and has collected hundreds of experimental verifications. Not only that, but we could also use a theory of gravity which is both mathematically sound, and explains further the clocks, the attraction between bodies with mass, as well explains a large number of other otherwise unexplained observations, and makes testable predictions which, as in the case of special relativity, have been experimentally verified over and over.

Both assumptions use exactly the same numbers in every case.

Really? Show me some numbers. Can you name any other theories that perfectly explains and predicts the clock's (ANY clock in this situation) behavior, explains gravity, explains the electrodynamics of moving bodies, which has also been experimentally verified time and time again?

This is the purpose of science, Stripe -- to develop testable, working models of our universe which explain and predict.

If you want to throw out our modern theories and instead assume some magical force called gravity (remember, you have to discard modern theories of gravity to even assume that it doesn't have a relativistic effects) somehow magically effects all clocks to the same degree, while at the same time discarding our ability to explain a large number of observations because of your personal preference, then by all means go play in your imaginary universe. The rest of the world is moving on and continuing to further our knowledge of the universe.

 

[Stripe]

Funny, you said "here's the math", but I didn't see any math whatsoever.

:chuckle: You're right. Here's a description of what might happen.

First of all, for the second or third time, you can't use current models of gravity without including general relativity.

You mean I can't use a relativistic model without using relativity? Thank goodness I'm not attempting that!

You can't even invoke gravity acting on the clock, at all, without incorporating a relativistic picture OR discarding the entire modern theory of gravity in favor of some pre-enlightenment ignorance where gravity is this mysterious phenomena we can't explain.

You can explain gravity?! Please share!

Sure, we could take blind stabs at adding a correction factor for each altitude at each velocity at each altitude, poking around in the dark, bumping into large corners, never really knowing whats going on or why the our clocks keep "malfunctioning" (all by the same factor, an important point you keep overlooking), and wasting a lot of time and money in the process.

We'd get a set of graphs. We could name them after someone.

Or we could turn on the light and use the theory that explains whats going on, preempt those corners, understand why our clocks are behaving the way they are, correct them before they're even in orbit, and to boot have a coherent theory of electrodynamics with a solid mathematical foundation which is derived from well accepted and tested equations, and has collected hundreds of experimental verifications.

Like I say. All that would be possible. The only difference would be the initial assumption. It's basically a name change, although it might be a simple change that revolutionises understanding.

 

[Lighthouse]

The perceived distance required to travel from A to B changes. As you approach the speed of light, distances shorten... To a photon (which is traveling at the speed of light), it seems to cover 0 distance.

I really wish I could remember those equations.

Perceived distance, or actual distance?

If the former, I knew that. If the latter, it's a lie.

Of course, one must remember that this theory came from the same amn who said you could never really get where you're going because there are an infinite number of spaces between point A and point B, no matter how far you have moved from one to the other.

Or maybe that was someone else and the movie IQ just had his "niece" say it to Tim Robbins' character because it was a physics theory...

In this case, it doesn't even present a direct challenge to the Bible.

Actually it does. All the people refuting this theory are of the Open View. Those who believe the Bible shows that God does not know for certain events that have yet to happen, because they do not yet exist. He knows His plans, of course, but even then if they are conditional He does not know for certain if they will come to pass, because He does not know what those on whom the plan's fruition depends will do. Because they haven't done it. In other words, God is not outside of time, because time is not a dimension, it is merely the concept of our experience of the passing, duration or succession of moments, from one to the next.

It seems that there is a basic mistrust of Science in general, combined with the hubris of thinking they have the knowledge and ability to judge things they know almost nothing about.

It is not the science we mistrust. It is the scientists who theorize upon matters that common sense would dictate as very simple.

I mean, what was it about time that led Greek Philosophers to theorize gods were outside of it? What was it about time that led Einstein to theorize that it was relative, rather than just our perceptions being relative?

There is absolutely no valid or rational reason to believe that time itself changes, effecting our perceptions of it.

If two people are in a room for eight hours and it seemed to one to not take that long, and to the other it seemed to be much longer, the only difference was in the perspective of the two people. Not in the actual passage of time itself. And to posit otherwise in such a leap of logic that a 10 year old is dumbfounded by the warped logic of the whole thing.

It is not that I do not understand these theories. It is that they are highly illogical to me.

Of course, if I've heard it once I've heard it a million times, the higher someone's IQ the less common sense they have. Einstein was too smart for his own good.

Special and general relativity both deal with the relativity of time, which is what we are discussing. "Is time absolute or relative?" I think most people find special relativity much easier to discuss in every day terms, whereas general relativity tends to be more abstract.

However, there is a conceptual connection can be made between special and general relativity. In special relativity (the previous videos), observers at rest observe the clocks of objects in motion ticking slow. This is because from the standpoint of the observer at rest, light has more space to travel through, and since light's speed through space is constant, time appears to slow down for the observer in motion.

Connect this with general relativity which says that gravity is actually the curvature of space. Thus, similar to high velocity, in high gravitational fields, light's path through space isn't straight. And in just like with high velocity, clocks in different gravitational fields will note time passing differently because the geometry of space will be different for each observer. This is all shown with differential geometry, which is why special relativity is a bit easier to grasp.

General Relativity Part 1

General Relativity Part 2

:listensst... Your videos aren't working.

 

[chair]

...It is not the science we mistrust. It is the scientists who theorize upon matters that common sense would dictate as very simple.

I mean, what was it about time that led Greek Philosophers to theorize gods were outside of it? What was it about time that led Einstein to theorize that it was relative, rather than just our perceptions being relative?

There is absolutely no valid or rational reason to believe that time itself changes, effecting our perceptions of it.

If two people are in a room for eight hours and it seemed to one to not take that long, and to the other it seemed to be much longer, the only difference was in the perspective of the two people. Not in the actual passage of time itself. And to posit otherwise in such a leap of logic that a 10 year old is dumbfounded by the warped logic of the whole thing.

It is not that I do not understand these theories. It is that they are highly illogical to me.

Of course, if I've heard it once I've heard it a million times, the higher someone's IQ the less common sense they have. Einstein was too smart for his own good.

:listensst... Your videos aren't working.

There are several Scientific theories that appear 'illogical' and that a ten year would think is crazy. But these theories weren't dreamed up by a bunch of bored idiots. These theories came about because the standard, 'logical' theories didn't work under certain circumstances.

In short, you are rejecting something that you know nothing about out of ignorance. And you apparently think that low intellegence is teh key to understanding the world.

I know little about reletivity. I do know a thing or two about quantum mechanics. it is completely 'illogical'. Any ten year old would tell you that. Even Einstein though it was nuts. But it works. And it is a valid scientific theory whose results you use and observe every day.

 

[dan1el]

I tried telling him that, but, as you can see, he still thinks all knowledge can be derived from common sense. And frankly, why shouldn't it? It's not like relativistic effects are undetectable in the world as we experience it in our day-to-day lives. If they were there, we should obviously have an intuitive understanding of them.

 

[Johnny]

It is not the science we mistrust. It is the scientists who theorize upon matters that common sense would dictate as very simple.

How much experience do you have with science? Anything beyond high school? You think scientists just sit around bored seeing who can come up with the weirdest explanation for things? And do you think generations of scientists who come after them just accept those explanations? This isn't religion, you know. Sitting around throwing out your personal opinion doesn't get you anywhere in science, and you'll never experience such intense scrutiny of your ideas as when you try and explain your ideas to scientists.

Obviously you've never spent any significant time around scientists who do actual research. You give them very little credit (and you give far too much credit to your "common sense"), despite the fact that they, and their "theorizing" have made your comfortable modern life possible. The universe does not play by human rules, and common sense doesn't get you very far in the sciences. Anyone with any science background will quickly acknowledge this.

It is not that I do not understand these theories. It is that they are highly illogical to me.

Of course, if I've heard it once I've heard it a million times, the higher someone's IQ the less common sense they have. Einstein was too smart for his own good.

...and the only people who really claim this are stupid people. It's like they need something to be proud of, so they tote around their mastery of this esoteric term they've invented called "common sense". Give me a break. It's kind of like "don't bother me with all those facts, I have really good instincts."

Psst... Your videos aren't working.

I just tested them, they work fine.

Oh, you mean they're not converting you? I never expected them too. I thought it would be helpful for you guys to be able to have something to argue with.

 

[Johnny]

First of all, for the second or third time, you can't use current models of gravity without including general relativity.

You mean I can't use a relativistic model without using relativity? Thank goodness I'm not attempting that!

Oh. What theory of gravity are we to assume for your scenario, then?

Sure, we could take blind stabs at adding a correction factor for each altitude at each velocity at each altitude, poking around in the dark, bumping into large corners, never really knowing whats going on or why the our clocks keep "malfunctioning" (all by the same factor, an important point you keep overlooking), and wasting a lot of time and money in the process.

We'd get a set of graphs. We could name them after someone.

So we'd be back to square one -- sitting there with some unexplained data.

Like I say. All that would be possible. The only difference would be the initial assumption. It's basically a name change, although it might be a simple change that revolutionises understanding.

No. You are suggesting that we throw two fundamental models of our universe out the window because you can't get a grasp on, or don't like, their implications. You're a throw back to the dark ages!

 

[Yorzhik]

Oh. What theory of gravity are we to assume for your scenario, then?

So we'd be back to square one -- sitting there with some unexplained data.

No. You are suggesting that we throw two fundamental models of our universe out the window because you can't get a grasp on, or don't like, their implications. You're a throw back to the dark ages!

This back and forth is all very interesting, but it doesn't answer which clock is wrong in the original scenario.

You have 3 clocks, 2 of which are on earth and do not agree. According to the 3rd clock, the solar system, which clock does relativity say is right, or which one is wrong?

And just so you know better for the future Johnny, there is no such thing as the "dark ages" if you are trying to refer to a time when the church held back knowledge.

 

[Johnny]

This back and forth is all very interesting, but it doesn't answer which clock is wrong in the original scenario.

You have 3 clocks, 2 of which are on earth and do not agree. According to the 3rd clock, the solar system, which clock does relativity say is right, or which one is wrong?

Relativity says both clocks are right, as there is no privileged frame of reference. Even our solar system is in an inertial frame, as it's whirling around the center of the galaxy at 250km/sec and under the influence of the gravitational field of the center of our galaxy. And even our galaxy is whirling around in the gravitational influence of our local galaxy cluster. One of the postulates of relativity is that there is no privileged frame of reference -- the laws of physics are the same in any frame.

And just so you know better for the future Johnny, there is no such thing as the "dark ages" if you are trying to refer to a time when the church held back knowledge.

I was using that term to generally refer to the pre-enlightenment era -- perhaps not technically correct but the point was to convey that. I wasn't trying to imply anything about the church. Thanks for the kind correction though!

 

[Yorzhik]

Relativity says both clocks are right, as there is no privileged frame of reference. Even our solar system is in an inertial frame, as it's whirling around the center of the galaxy at 250km/sec and under the influence of the gravitational field of the center of our galaxy. And even our galaxy is whirling around in the gravitational influence of our local galaxy cluster. One of the postulates of relativity is that there is no privileged frame of reference -- the laws of physics are the same in any frame.

Wouldn't the solar system be privileged relative to the 2 clocks on earth? One clock would show the time is 2 in the afternoon, and eventually the other clock would show it was 2 in the morning. Couldn't people at both clocks just look to see where the sun/stars were to find out what time it really was?

 

[Johnny]

Wouldn't the solar system be privileged relative to the 2 clocks on earth? One clock would show the time is 2 in the afternoon, and eventually the other clock would show it was 2 in the morning. Couldn't people at both clocks just look to see where the sun/stars were to find out what time it really was?

No, this is kind of where everyone gets hung up. The short reason is that if we assume is the sun is the "correct clock", then we have said that the laws of physics are more valid for the sun and our solar system than they are for the man standing on the mountain. One of the axioms of physics (and of relativity) is that the laws of physics are equally valid for any observer in the universe.

This issue tends to be confusing, and its where Bob Enyart seemed to get hung up. Humans have devised a time keeping system which originally depended on the sun. We decided that sun up to sun up would be one full "day". Later, when the hour system was devised, we divided up this full day into a 24-hour period. So we devised this time keeping system that would count hours with the idea that we could associate certain hours with the sun's position. The important point here is that we purposefully designed our clock system such that the sun's location would correspond to certain times on the clock.

That being said, the sun does not ever dictate how much time has passed for an observer. I'll give you two examples: (1) The earth's rotation is slowing. That means that over a long period of time, our days will gradually get longer. At some point in the not-so-long future, one complete earth rotation will take 25 hours. So we see right away that we're not defining how much time has passed by where the sun is in the sky. Otherwise we would always have 24 hour days, and the definition of an hour would be gradually shifting as the Earth's rotation slowed. (2) In the book of Joshua the sun stood still in the sky. That, in no way, means that time stopped because the Earth stopped rotating.

So with that in mind, note that the sun is not actually a perfectly accurate time-keeper for the observer on the mountain. Nor is it a perfectly accurate clock for the observer at the base of the mountain. The observers will agree on the sun's location, but they won't agree on how long it took to get there. Thus, if one observer's clock reads 2am in the middle of the day, that doesn't mean his clock is keeping time wrong. The error is introduced because the we designed our clock system such that 2am always occurs when the sun is down. But his clock is only counting hours (or seconds), and since he has experienced more hours, then it is only natural that his clock will read 2am. As in the examples earlier, the sun is not an indicator of how much time has passed. Our 24-hour system was not designed with relativistic effects in mind, so of course you're going to get screwy 2am with the sun-up kind of results when you start introducing relativistic effects into a clock-system that was designed long before these effects were even known.

 

[Stripe]

Sounds like you just need the laws of physics to be constants. Why do you need them to be constants when we can simply calculate how much they are affected by gravity (or velocity) and get the same results?

 

[Johnny]

Sounds like you just need the laws of physics to be constants. Why do you need them to be constants when we can simply calculate how much they are affected by gravity (or velocity) and get the same results?

Sounds like you just made this sentence up. It's so chock full of huh? that it's hard to even respond to.

(1) What laws of physics are you referring to?
(2) I don't need any laws of physics to be constant. That's an axiom of science.
(3) You could never calculate how much the laws of physics differ in any one portion of the universe without invoking laws of physics to do so. And since you've argued that they're not constant, then invoking them to calculate or predict anything can never be justified.
(4) These two sentences are entirely misdirected.
(5) Show me how the "calculations" give you the same results.

Do see how entirely ludicrous your position has become? You've now advocated throwing out two major theories which explain a vast number of phenomenon in favor of plotting data points on a graph and some blind guesswork, and now you're actually arguing that the laws of the universe aren't actually the same for everyone. The former of those arguments going against the very grain of what science does, and the latter actually undermining all of science by throwing out one of its principle axioms. Your position is patently absurd.

 

[Clete]

So with that in mind, note that the sun is not actually a perfectly accurate time-keeper for the observer on the mountain. Nor is it a perfectly accurate clock for the observer at the base of the mountain. The observers will agree on the sun's location, but they won't agree on how long it took to get there.

It seems it is you who are hung up.

The fact that both observers agree on the sun's position is precisely what proves time itself to be constant and that it is their respective clocks that are effected by the gravity well. If it were time itself then the Sun would be down for one and high in the sky for the other because the position of one observer on a mountain top has no effect whatsoever on how long it take for the Earth to spin on its axis.

This is why I've all but completely dropped this discussion. You guys throw your educated vernacular around enough to confuse the issue and get yourselves off the topic of Bob's article just enough to make it sound like you've actually responded to it when all you've actually done is prove his point! And now that I've pointed that out again, its your turn to deny it and say something about how none of us know what the hell we're talking about. Its really become a dreary and quite non-relativistic waste of everyone's time.

Resting in Him,
Clete