Quite. There is also the unspoken assertion that clocks here on Earth read the ‘correct’ time, ignoring that Earth itself is moving through space at a fair clip.
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Completely backwards. Physical senses are far inferior to instrumentation for obtaining empirical data. Personal experience is subjective.
In other comments, you seem to place direct sensation as more physical or less inferential than instrumental measurement as an arbitrator of reality - is that the case?
In a sense, our immediate sensory is more direct and less inferential than the data we obtain from instrumentation - the only way for that data to get into our heads, after all, is to read it off a display. So we have to have some degree of trust our senses before we can learn anything from more sophisticated experimental equipment.
Of course, this doesn’t mean we can’t genuinely learn anything from that experimental equipment.
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Another way to put it is that all non-accelerating inertial frames are equal. All of the same natural laws apply to all reference frames. However, you can see differences between reference frames (i.e. relativity).
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Our immediate sensory inputs are subjective, not objective.
Trust is established by repeatability between multiple experiments and multiple observers.
True, instrumentation is a step removed from direct consciousness, and that can lead to error. When I was an industrial programmer, I was always impressed by how reluctant operators were to disbelieve anything presented on a control room screen, even when I was in a position to know there had to be a calibration or configuration problem.
But to offer an example of why we should trust instrumentation over our senses, consider flying by wire. As a pilot, there is a tension between what your mind integrates as your sensory awareness and what your instruments display; a lot of night flight aviation accidents have been due to the human impulse to trust senses. A Ptolemaic cosmology and Aristotelian mechanics comports quite well with our senses, but are revealed to be wrong.
Much of our advance in science seems to derive not so much that we are becoming more clever in our experiments and theorizing, but due to the circular progression of science breeding improvement in technology, which in turn allows for more sensitive and precise experiments. Even after a career in industrial instrumentation, I often find myself wondering “how in the world can they measure that”? To the layperson, it must feel a world apart, and cause for suspicion. And to be sure, the very fringe of discovery will always be on the very fringe of measurability. Eventually, measurements and confidence improves, and knowledge proceeds from the penumbra to the light of day.
So I agree that the role instrumentation has in epistemology should be critically appraised. There has been much discussion of manufactured tools as a badge of humanity, which allow us to act on our environment, but instruments are created for so that our environment can speak back to us, and this is a hallmark of our civilization, including science. What tools are to muscle and sinew, instruments are to our senses. At least, that is my intuition?!?
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I don’t really see any difference between saying time as measured by clocks is slowing down or speeding up, and time is slowing down or speeding up. Time is always referring to a measurement by some kind of a clock is it not? So what’s the difference?
This to me is what is indisputable. What is causing the clock rates to change is what is disputable.
It seems the answer to the question being discussed is being implied here without an explanation, that time changes speed and somehow affects the clock rate. As I understand it, the mechanism used in atomic clocks to measure time is the regularity of the occurrence of the oscillation rates. How would that mechanism detect when time itself is slowing down, even if that were to actually happen?
It only naturally follows if the concepts of GR are assumed to be true.
Yes. But what I’m challenging is the fact that in mechanical theories in physics such as relativity they are basing the claim of the concepts being true, what appears to be unjustifiably, on only one piece of evidence while ignoring other relevant evidence. So far no one to my knowledge has been able to show that what I’m arguing is not the case.
Where did I say that using instruments doesn’t count as empirical verification? All I said is that there is no instrument that can observe or photograph what time looks like. There are all kind of instruments that can be used to observe physical objects or detect physical existence. However, none of them that I’m aware of are able to observe time itself.
The very nature of gravity necessarily calls for it to have causal powers. The very nature of time does not necessarily call for it to have causal powers.
The key word here is fiction.
Yes, clock rates slowing down are observed. But time itself slowing down has never been observed. It has to be inferred. I’ve had this discussion already with others on this thread. I’m not particularly interested in going around in circles on this again.
Because I see time as a relationship between past, present and future, not as some kind of substance with causal powers that can affect and be affected in a physical manner.
The discussion is not centered around relativistic equations and the empirically verified effects of what those equation describe. It’s about the truth of the concepts. In particular, in that regard, what’s being talked about is actual confirmed differences of clock rates at different altitudes.
Atomic clocks are somehow affected when positioned higher or lower in the earth’s gravitational field. What explains that? Is it because the concept that time for some unknown reason changes speed whenever atomic clocks are positioned differently, and those very clocks which have no known mechanism built into them for detecting changes in the speed of time (if time is even some type of real substance that is able to change speed) are able to detect such type of changes?
Or is it the seemingly more obvious answer that the gravitational fields are somehow affecting the oscillation rates of the clocks? The latter seems to me to make the most sense and to be the simplest, most straightforward explanation with the most explanatory power and scope based on relevant evidence of all that we know and experience.
Basically atomic clocks work by registering amounts of regular occurring oscillations, at least that’s my understanding. My question is, even if time itself is some kind of real substance and actually is able to change speed, what is the mechanism that enables clocks to somehow detect such a change in the speed of time?
That’s not something that clocks are specifically designed to do. There’s nothing in human experience of reality that I’m aware of that would suggest that it’s even plausible to think that they have such a capacity.
But everything is some kind of clock. The electrons swirling in your body swirl at a given rate. The electrical connections which constitute your thoughts. Everything is subject to entropy. There is no non-clock, it is all clock.
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It can all be used as a clock to measure time, if that’s what you mean. But what relevance does that have with the discussion?
It has everything to do with the discussion. Time would still permeate reality were there no clocks that people could use to measure it by, but relativity would still determine the duration of that reality with respect to other frames. Clocks only measure time because time is an essential attribute of our existence. There is nothing otherwise special or distinct about clocks in particular. That they oscillate or whatever just makes it convenient to display some sort of readout. So whatever influences clocks influences the very fabric of space and time itself.
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That depends on what your view of what time is. Seems to me what you’re expressing is a substantivalist view of time. Is that correct?
What other relevant evidence?
Clocks can.
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When I last asked Jim what this other evidence to consider was, this is basically what he said:
In other words, it seems that the other “evidence” is simply that Jim thinks his own explanation is more intuitive. But I’m not sure his intuition is shared by others. Certainly not by me, since I’ve just been confused by what he’s trying to say.
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I don’t think GR is saying anything different. GR simply says that gravitational fields result from the bending of space and time, which also affects clocks that are measuring time. So I don’t see what your disagreement is.
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I am saying that measurement is not so much merely an empirical reality, but is an inherent reflection of the reality of our existence.
The substantivalist vs relationalist debate is an interesting and legitimate discussion, but there is more baggage there that I do not really take a position on.
I’ve already had this discussion with @dga471 as he has pointed out. But since he didn’t seem to get what I was saying I’ll try again. To continue using time dilation as an example, we know that changes of positions of atomic clocks in the earth’s gravitational field appear to be correlated to changes in clock rates. That’s one particular piece of evidence that can be used to support changes in where clocks are placed in respect to the strength of gravitational fields as the cause that doesn’t seem to be considered when evaluating the claim that time slowing down is what affects clock rates.
There’s also the fact that what we intuitively experience generally in reality doesn’t relate at all to the idea of time being some kind of substance, or existing in some kind of physical manner, and that it can somehow have causal powers and can change its speed. And the fact that we don’t have any observations of time itself also calls into question it existing as some kind of substance.
But I think the biggest weakness of the claim is, besides the psychological evidence which I would argue is weak at best, there is really only one substantial piece of evidence to support it, i.e., that the concept is employed in a successful theory.
And really all I’m intending to do with the claim I’m making is to point out that there are other alternative explanations besides those of the concepts in question that are reasonable inferences based on the evidence, and that they are generally not recognized by the scientific community.
I’m not saying that holding to the truth of concepts in mechanical theories based on their being employed in successful theories is without any justification. But what I am saying is that there are other alternative explanations that are just as plausible, if not more so, and scientists should generally be willing to recognize that.
Haven’t we already discussed this more than once?
So are you saying clock rates change because of the bending of spacetime, or that they change because time slows down? Don’t see how you can have it both ways.
Sorry, I misread what you were saying in that last post.
It seems to me that may be the case if the concept of a spacetime continuum is assumed to be true. But I’m not convinced that it is. And that still doesn’t seem to be addressing the issue of what it is that is causing the clock rates to change.
It is considered. The inner workings of atomic clocks are well understood and they are designed to not be influenced by gravitational pull.
We can objectively measure time itself. We do that with clocks.
My statements have only been met with flat denial with no real justification.
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I doubt if many people would call time some kind of ‘substance’. More, it is a fundamental element of our reality. Just like gravity, which has also never been observed - only its effects.
Have you ever listened to Richard Feynman talking about magnetism and how we cannot hope to explain this in more fundamental terms?
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From a physics point of view (which is all I’m trying to argue in this thread), the second statement is a tautology. For time to “slow down” means nothing more than for clocks to slow down. To say that “time causes the clock to slow down” is not an informative statement; it is like saying “Donald Trump caused the President of the United States to have a press conference today.”
This argument isn’t strong, because you haven’t properly defined what “substance” is other than pointing to an SEP article mentioning substantivalism which doesn’t use the term “substance” in the same way as we use to refer to chemicals or atomic structures. It seems that your counterargument relies on a confusion of the meaning of the term “substance”:
- Only substances can cause anything.
- Substances are usually atomic structures.
- Time isn’t an atomic structure.
- Therefore, it’s unlikely and implausible that time can cause anything.
As you can see, this argument fails because the definition of “substance” in 1) and 2) are not necessarily co-extensive.
I don’t understand how this is a good counterargument, or even an intelligible one. You’re basically saying that “X is a weak claim because there’s only one good argument for it.” Well, if it’s a really good argument, that’s all we need.
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Within the frame the clocks do not slow down, therefore nothing is causing the clock rates to slow down, so it does address that issue. The question is what “causes” clocks in different frames to go out of synchronization.