DParlevliet Posted November 2, 2015 Posted November 2, 2015 This seems just as illogical as the claim that because we can use change to measure time, time is defined by change. Isn't time always measured as a distance?
Strange Posted November 2, 2015 Posted November 2, 2015 Isn't time always measured as a distance? No. What gives you that idea?
DParlevliet Posted November 2, 2015 Author Posted November 2, 2015 No. What gives you that idea? Every clock (I think also an atomic clock) is basicly measuring distances. That does not imply that time is a distance. The fourth dimension is not visible for us, so cannot be measured directly, only by its effect in 3D space.
Strange Posted November 2, 2015 Posted November 2, 2015 Every clock (I think also an atomic clock) is basicly measuring distances. I can't think of an example. I was going to suggest a clepsydra or using a candle to measure time. But these use the rate at which water drips or the rate at which the candle burns. Clocks measure time, not distance. The second is explicitly defined with no motion and atomic clocks (as I'm sure swansont will tell us in more detail) attempt to reduce movement and then correct for errors due to any residual motion.
swansont Posted November 2, 2015 Posted November 2, 2015 Every clock (I think also an atomic clock) is basicly measuring distances. That does not imply that time is a distance. The fourth dimension is not visible for us, so cannot be measured directly, only by its effect in 3D space. No, atomic clocks do not measure a distance.
DParlevliet Posted November 2, 2015 Author Posted November 2, 2015 A clepsydra measures the travelling distance of water. A candle measures the distance it is burned A atomic clock depends on a jump inside an atom Essential you measure a movement, which is l/t. If you measure l, you know t, or better, you have a reference for t
studiot Posted November 2, 2015 Posted November 2, 2015 (edited) Every clock (I think also an atomic clock) is basicly measuring distances. My atomic clock counts decayed radioactive atoms. Distance is not involved. My charge clock measures the charge on a capacitor. Again distance is not involved. I'm sure others can think of more clocks which only have to count. Edit Paleontologists use yet more methods of measuring time. For instance. http://www.scienceforums.net/topic/87968-fossil-use-in-calibrating-molecular-dating/ Edited November 2, 2015 by studiot
Strange Posted November 2, 2015 Posted November 2, 2015 A clepsydra measures the travelling distance of water. A candle measures the distance it is burned No, those are what your read to determine the elapsed time. What is measured is the rate (i.e. time) at which the water drips. A atomic clock depends on a jump inside an atom No it doesn't. It measures frequency (i.e. 1/time).
swansont Posted November 2, 2015 Posted November 2, 2015 Even a pendulum clock doesn't measure a distance — the period is independent of the amplitude of the oscillation (to first order, at least) But what distance is there in a spin flip of an electron in an atom, and how is that being measured?
Strange Posted November 2, 2015 Posted November 2, 2015 Another popular example of time passing with no movement involved: take an individual, stationary muon (i.e. observed in its own frame of reference). It is a fundamental particle so there are no internal components and therefore nothing to move. And yet, after a few microseconds, it will decay. So time passed with no change and no motion.
geordief Posted November 2, 2015 Posted November 2, 2015 Another popular example of time passing with no movement involved: take an individual, stationary muon (i.e. observed in its own frame of reference). It is a fundamental particle so there are no internal components and therefore nothing to move. And yet, after a few microseconds, it will decay. So time passed with no change and no motion. How do you measure the time in that situation? How do you know what has occurred in the muon? Is it not by the use of a beam of light? (apologies if I am wrong -I am just prodding ) Are there any situations where time can be physically counted (not inferred) without a beam of light being used at some point in the process?
Strange Posted November 2, 2015 Posted November 2, 2015 Are there any situations where time can be physically counted (not inferred) without a beam of light being used at some point in the process? I have a talking clock: no moving parts, no light. Just press a button on top and it speaks the time.
swansont Posted November 2, 2015 Posted November 2, 2015 How do you measure the time in that situation? How do you know what has occurred in the muon? It's not a measurement, per se, but an example of time passing with no movement. You could count the number of decays in an ensemble and get a measurement of the time, which would not be a measurement of motion.
robinpike Posted November 2, 2015 Posted November 2, 2015 Another popular example of time passing with no movement involved: take an individual, stationary muon (i.e. observed in its own frame of reference). It is a fundamental particle so there are no internal components and therefore nothing to move. And yet, after a few microseconds, it will decay. So time passed with no change and no motion. Not sure if you meant that to be taken as fact - or just a possible example - but the muon decaying into multiple particles suggests that it is not a fundamental particle. Are there any examples involving multiple particles that we can be sure do not involve distance / motion to measure time? Even Swansont's example of an electron's spin flip involves the electron and the nucleus.
swansont Posted November 2, 2015 Posted November 2, 2015 Not sure if you meant that to be taken as fact - or just a possible example - but the muon decaying into multiple particles suggests that it is not a fundamental particle. No, it doesn't suggest that. Feel free to open a new thread to discuss why that is. Regardless, what does this have to do with measuring a distance? Even Swansont's example of an electron's spin flip involves the electron and the nucleus. That's not a measure of a distance, so again I'm not sure how this is relevant.
robinpike Posted November 2, 2015 Posted November 2, 2015 (edited) No, it doesn't suggest that. Feel free to open a new thread to discuss why that is. Regardless, what does this have to do with measuring a distance? That's not a measure of a distance, so again I'm not sure how this is relevant. Because then it would be clear cut if there was an example of change which only involved a single fundamental particle. When there are two or more particles involved, there is the possibility of motion between the two - even if that possibility is not the common view. And motion between particles requires a change in distance. Edited November 2, 2015 by robinpike
Strange Posted November 2, 2015 Posted November 2, 2015 Because then it would be clear cut if there was an example of change which only involved a single fundamental particle. A single muon decaying is an example of that.
studiot Posted November 2, 2015 Posted November 2, 2015 Robin Pike Because then it would be clear cut if there was an example of change which only involved a single fundamental particle. When there are two or more particles involved, there is the possibility of motion between the two - even if that possibility is not the common view. And motion between particles requires a change in distance. geordief Are there any situations where time can be physically counted (not inferred) without a beam of light being used at some point in the process? I gave several examples in post#7
geordief Posted November 2, 2015 Posted November 2, 2015 I have a talking clock: no moving parts, no light. Just press a button on top and it speaks the time. Am I being facetious.? You press the button and that involves electro -magnetism(I am just trying to tag along) I think you are being facetious but maybe I deserve it for asking questions outside my remit.
Strange Posted November 2, 2015 Posted November 2, 2015 Am I being facetious.? You press the button and that involves electro -magnetism(I am just trying to tag along) I think you are being facetious but maybe I deserve it for asking questions outside my remit. I wasn't being facetious. It is a fairly obvious example of "where time can be physically counted (not inferred) without a beam of light being used at some point in the process".
geordief Posted November 2, 2015 Posted November 2, 2015 I wasn't being facetious. It is a fairly obvious example of "where time can be physically counted (not inferred) without a beam of light being used at some point in the process". Thanks. I will go away and try and work my way through that (eventually I hope).
robinpike Posted November 2, 2015 Posted November 2, 2015 A single muon decaying is an example of that. Thinking this through, so if the muon decays without needing (or getting) outside influence, does this mean that the muon has a clock inside itself? If not, what determines when it decays?
DParlevliet Posted November 2, 2015 Author Posted November 2, 2015 (edited) No, those are what your read to determine the elapsed time. What is measured is the rate (i.e. time) at which the water drips. Indeed, that is what I mean. The fourth time dimension is impossible to see directly by us, so it is measured by its effect in 3D space, so by the only other dimension in there: distance. In the example one measures the movement of water (in the restriction). Often time measurements depends on energy decrease, analog or in steps. But energy is potential or kinetic, both depending on distance. - Atomic clocks are based on the wavelength of radiated photons, which is determined by the jump of electrons between orbits inside the atom. - I don't know charge clocks, but (dis)charging is caused by moving electrons over a distance in a field. - A pendulum clock measures the rotation distance of wheels. - As geordief told: if you don't know the cause of decaying muons, you don't know if distance is involved or not. The same for C14 dating. - The time measuring part of a talking clock is the same as any other clock - How do you measure time with spin flip? Edited November 2, 2015 by DParlevliet
Strange Posted November 2, 2015 Posted November 2, 2015 Indeed, that is what I mean. The fourth time dimension is impossible to see directly by us The same is true of the three spatial dimensions. You can only measure distance by changing the position of something over time. In fact, every time this particular argument comes up, all I do is replace "time" with "space" in all of your examples. Why not save us all time by doing that yourself. if you don't know the cause of decaying muons, you don't know if distance is involved or not. Sounds like the usual objection by those with this (quasi-religious) belief: "the muon can't be fundamental because there must be something moving" Why must there be something moving? "because it measures time". This is the highly popular logical fallacy of Begging The Question. The time measuring part of a talking clock is the same as any other clock That was in response to a different question about beams of light.
swansont Posted November 2, 2015 Posted November 2, 2015 - Atomic clocks are based on the wavelength of radiated photons, which is determined by the jump of electrons between orbits inside the atom. In many atomic clocks you are not measuring the wavelength of the emitted radiation; there actually is no emitted radiation being measured. (in others there is, but you are just counting photons rather than doing a wavelength measurement) - A pendulum clock measures the rotation distance of wheels. No, not really. The period is set by the length of the pendulum, not the size of any of the gearing. - How do you measure time with spin flip? You, in effect, count the number of flips (more technically you measure the interference signal between a local oscillator that arises owing to the flips so that it's not a discrete number of oscillations). That's how passive microwave atomic clocks work. Is it possible you don't know as much about atomic clocks as the certainty of your posts implies? - As geordief told: if you don't know the cause of decaying muons, you don't know if distance is involved or not. The same for C14 dating. But how is it then possible to be sure, as you are, that a distance is involved?
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