# Distance and clocks (split from how fundamental is light)

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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 it does, it is not a very accurate one as the muon decays at a random time (centered around an average of about 2 us)

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- Atomic clocks are based on the wavelength of radiated photons, which is determined by the jump of electrons between orbits inside the atom.

If this was a response to my post 7 then try reading it again properly.

I don't know charge clocks

But you are prepared to pronounce yourself expert anyway?

Consider any physical quantity $\Psi$.

Then if there exists any function such that

$\frac{{d\Psi }}{{dt}} = f(t)$ ; where t is time

That is the rate of change of this quantity is a function of time alone, then this equation can be used as the basis of a distance indepedent clock as you originally asked for.

A simple quantity is number and I offered this in my atomic clock.

$\frac{{dN}}{{dt}}$

is quite independent of distance (or the motion of counter or material , though that was not actually specified).

In fact the progress of many chemical reactions can be measured in this way.

The reaction will proceed equally well in a petri dish or a swimming bath or a tall measuring cylinder.

The same rate laws apply to all.

You also need to understand the difference between the dependent and the independent variable.

Some processes can depend on time, but measurement can be most conveniently made as a distance, for example the burning of the candle you mentioned or the reading in a fuel tank sight gauge.

In both cases a distance is a convenient (dependent) function of time, which is the independent variable. The actual property changing is a different dependent variable that is more difficult to measure than distance.

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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?

"Atomic clocks are based on the wavelength of radiated photons, which is determined by the jump of electrons between orbits inside the atom."

The hyperfine transition - which is a point particle going from spin up to spin down through interacting with the nuclear spin - flips between two very close energy levels - it is not a gross orbital change

"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."

Aren't muons treated as point particles - ie no distance involved

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Aren't muons treated as point particles - ie no distance involved

Indeed. Not only is there no internal structure, there is no room for internal structure.

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- The time measuring part of a talking clock is the same as any other clock

While many electronic clocks do rely on one moving part (a crystal) for time keeping, there is no sense in which you can say that distance is used measure time because there is no net movement, just a tiny constant oscillation. So what is being measured is the rate (1 / time) at which the crystal oscillates.

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Why are relativity (and kwantum) fora always so angry. What a dreadful profession it must be, where discussions are not possible without personal attacts within a few posts. See the question-mark in my first post,. A question-mark means I am asking, because I don't know (am not sure). If I knew, I would not post it. There is not a single post in which I pronounce myself an expert, because I am not. I just discuss with arguments.

Regarding atom clocks, Wiki tells: "it uses the microwave signal that electrons in atoms emit when they change energy levels." So it depends on energy levels of electrons, which I think is potential energy depending on the electron (average) position/distance from the atom core

In an oscillation crystal the movement of the cystal is measure, determinded by the distance and elastic properties. This is done multiple times in two directions. It does not matter if all those add up or not, that is the way of measuring. Also mechanical clocks have an oscillating net movement, but by its construction it adds up in moving wheels.

A mechanical clock without pendulum also measures time, but inaccurate. The pendulum provides accuracy, and indeed also depends on length.

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Why are relativity (and kwantum) fora always so angry.

Who is angry? Do you always assume that people who disagree with you are angry?

A question-mark means I am asking, because I don't know (am not sure).

And yet all you have done is repeat the same incorrect assertions. What is the point of asking if you are going to ignore the answers?

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Who is angry?

I am angry because DParliviet has been wasting my time.

Regarding atom clocks, Wiki tells: "it uses the microwave signal that electrons in atoms emit when they change energy levels." So it depends on energy levels of electrons, which I think is potential energy depending on the electron (average) position/distance from the atom core

I told you more than once that MY ATOMIC CLOCK DOES NOT WORK LIKE THIS.

In fact its function has nothing whatsoever to do with electrons or EM radiation.

Yet, as Strange (+1) says, you keep repeating this nonsense, instead of saying

"Hey, I've not heard of your type of atomic clock, please tell me more"

Edited by studiot
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...

Regarding atom clocks, Wiki tells: "it uses the microwave signal that electrons in atoms emit when they change energy levels." So it depends on energy levels of electrons, which I think is potential energy depending on the electron (average) position/distance from the atom core

...

Hopefully Doc Swan will set me straight - but my understanding of the caesium hyperfine transition is that the caesium atom has an electron configuration which leaves one 6s electron alone on the outer orbital (ie in my schoolboy chemistry terms it wants to form Cs+ ions) . An outer electron would normally interact magnetically through its spin with the interior electrons. But the interior electrons are perfectly balanced and have no net angular momentum apparent to the exterior election - there is no fine structure. However the electron can interact on a much weaker basis with the nuclear spin. There are two basic possibilities that the nucleus and the electron spins are parallel or they are antiparallel - the parallel is the slightly (ever so slightly) higher energy situation. The energy difference is 0.000038 eV - this is very small and about the energy of the microwaves the wiki mentions. Through feedback mechanisms involving (I think) resonance you can tune your driving microwaves so that they lock with the hyperfine transition - and at that point your microwaves have a frequency matched to that of the hyperfine transition of the caesium atom and you have a way of measuring time. More importantly to this discussion - the hyperfine transition is a switch of spin state; this is a quantum mechanical effect and is strictly non-classical - it doesnot involve the physical spinning of a little globe being turned over. There is no distance measurement going on

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Hopefully Doc Swan will set me straight - but my understanding of the caesium hyperfine transition is that the caesium atom has an electron configuration which leaves one 6s electron alone on the outer orbital (ie in my schoolboy chemistry terms it wants to form Cs+ ions) . An outer electron would normally interact magnetically through its spin with the interior electrons. But the interior electrons are perfectly balanced and have no net angular momentum apparent to the exterior election - there is no fine structure. However the electron can interact on a much weaker basis with the nuclear spin. There are two basic possibilities that the nucleus and the electron spins are parallel or they are antiparallel - the parallel is the slightly (ever so slightly) higher energy situation. The energy difference is 0.000038 eV - this is very small and about the energy of the microwaves the wiki mentions. Through feedback mechanisms involving (I think) resonance you can tune your driving microwaves so that they lock with the hyperfine transition - and at that point your microwaves have a frequency matched to that of the hyperfine transition of the caesium atom and you have a way of measuring time. More importantly to this discussion - the hyperfine transition is a switch of spin state; this is a quantum mechanical effect and is strictly non-classical - it doesnot involve the physical spinning of a little globe being turned over. There is no distance measurement going on

Pretty much, except offhand I can't recall if the antiparallel states have the higher energy or the parallel ones (you have several - signs to account for; but the opposite charge means the same spin would be opposite magnetic moments, which attract, so that's a lower energy. But I'd have to check to make sure there isn't some other - sign I'm forgetting)

The point is you are essentially counting oscillations, so even if there was a meaningful distance to be measured (and it's QM, so there really isn't), you aren't measuring that distance. Even for the quartz oscillator, you are measuring cycles (zero crossings of a resonator circuit) rather than distance.

Why are relativity (and kwantum) fora always so angry. What a dreadful profession it must be, where discussions are not possible without personal attacts within a few posts. See the question-mark in my first post,. A question-mark means I am asking, because I don't know (am not sure). If I knew, I would not post it. There is not a single post in which I pronounce myself an expert, because I am not. I just discuss with arguments.

Regarding atom clocks, Wiki tells: "it uses the microwave signal that electrons in atoms emit when they change energy levels." So it depends on energy levels of electrons, which I think is potential energy depending on the electron (average) position/distance from the atom core

As has been pointed out you seem to be confusing disagreement with anger.

Wikipedia is wrong here. Passive clocks do not rely on emitted radiation, and you aren't measuring a distance.

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If it does, it is not a very accurate one as the muon decays at a random time (centered around an average of about 2 us)

A random outcome could still be driven by a precisely timed process. I could roll a dice precisely every second and give you the result only when a one appears.

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A random outcome could still be driven by a precisely timed process. I could roll a dice precisely every second and give you the result only when a one appears.

Good point!

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A random outcome could still be driven by a precisely timed process. I could roll a dice precisely every second and give you the result only when a one appears.

Good point!

Thank you

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.

The answer as to whether time is needed to measure distance is not straight forward. I hope this reverse example helps everyone...

Suppose we try to measure the length of a rod using a ruler when there is no time. Seems obvious that it can be done, doesn't it?

So we bring the ruler up against the rod and then see if the ruler is shorter, exactly the same length, or longer than the rod.

Either the ruler can be placed within the ends of the rod, or the lengths of the two exactly match, or the ruler will stick out beyond the rod. That can only have one single outcome.

But remember there is no time.... How could removing time possibly change what is physically true?

Let's see.

So while we are trying to line up one end of the ruler with the rod, that light reaches our eyes at the same moment as the light when the ruler and rod have been aligned. Without time, those two events cannot be differentiated - it is not possible to know if the end of the ruler is extending beyond the end of the rod because we haven't aligned the two, or because the ruler is longer than the rod.

The conclusion appears to be that to measure length, i.e. to have the concept of length present, is impossible without time.

Edited by robinpike
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The answer as to whether time is needed to measure distance is not straight forward.

That's not the question being discussed.

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Does robinpike's line of argument belong in the thread from which this was split off ?

http://www.scienceforums.net/topic/91940-how-fundamental-is-light-to-the-physics-of-the-universe/

In post #5 of that thread Strange said

"You seem to be saying that because we can use light to measure distance, that distance must be defined by light. This seems just as illogical as the claim that because we can use change to measure time, time is defined by change. It is refreshing to see someone apply the same logic to space as to time, even if it is equally wrong."

Is robinpike's argument in line (or counter to ?) to that point?

I cannot really contribute as my head is below the water line but maybe robinpike could make that same point in the earlier thread ?

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Hopefully Doc Swan will set me straight - but my understanding of the caesium hyperfine transition is that the caesium atom has an electron configuration which leaves one 6s electron alone on the outer orbital (ie in my schoolboy chemistry terms it wants to form Cs+ ions) . An outer electron would normally interact magnetically through its spin with the interior electrons. But the interior electrons are perfectly balanced and have no net angular momentum apparent to the exterior election - there is no fine structure. However the electron can interact on a much weaker basis with the nuclear spin. There are two basic possibilities that the nucleus and the electron spins are parallel or they are antiparallel - the parallel is the slightly (ever so slightly) higher energy situation. The energy difference is 0.000038 eV - this is very small and about the energy of the microwaves the wiki mentions. Through feedback mechanisms involving (I think) resonance you can tune your driving microwaves so that they lock with the hyperfine transition - and at that point your microwaves have a frequency matched to that of the hyperfine transition of the caesium atom and you have a way of measuring time. More importantly to this discussion - the hyperfine transition is a switch of spin state; this is a quantum mechanical effect and is strictly non-classical - it doesnot involve the physical spinning of a little globe being turned over. There is no distance measurement going on

Thanks for the explanation. So the same as for C14 timing, from quantum effects we don't know the cause, so don't know where it depends on. Deep down it could be related to distances, but we don't know.

I relaised that you can measure time by any fundamental natural unit which changes in time. This is mostly length (distance), perhaps quantum effect, or a clock could be based on changing temperature. I should not know any other.

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Thanks for the explanation. So the same as for C14 timing, from quantum effects we don't know the cause, so don't know where it depends on. Deep down it could be related to distances, but we don't know.

I relaised that you can measure time by any fundamental natural unit which changes in time. This is mostly length (distance), perhaps quantum effect, or a clock could be based on changing temperature. I should not know any other.

If it's the case that we don't know how these are related to distance, how can we possibly be measuring a distance?

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If it's the case that we don't know how these are related to distance, how can we possibly be measuring a distance?

It is useless talking about items we don't know. As long as there is no prove that quantum effects are related to movement, it is a different way of time measurement.

However the decay C14 is not purely accidental. It has an average time. So something in the atom is determining this time. I cannot think of any other fundamental natural unit then movement (for instance as oscillation deep inside the atom). But that is my guess, no proof.

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It is useless talking about items we don't know. As long as there is no prove that quantum effects are related to movement, it is a different way of time measurement.

However the decay C14 is not purely accidental. It has an average time. So something in the atom is determining this time. I cannot think of any other fundamental natural unit then movement (for instance as oscillation deep inside the atom). But that is my guess, no proof.

Especially since decay completely consistent with being a random event

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Is it possible to ask "random in relation to what?"

Is that a meaningful question?

Might it be that the macro world is random and the micro world is determinant?

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Especially since decay completely consistent with being a random event

Decay is not fully random. It has a distribution around a certain decay time, specific for that decay. This time must be determined by something. Real random times has to pattern or predictability, so cannot be used to measure time.

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Decay is not fully random. It has a distribution around a certain decay time, specific for that decay. This time must be determined by something. Real random times has to pattern or predictability, so cannot be used to measure time.

Fully random?

Does your claim have a meaning other than being just plain wrong.

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I don't understand: if decay is random then all radioelements should decay more or less the same rate? Because they aren't it looks that it is pseudorandom with some obscure deterministic factor governing the rate of each radioelement.

Edited by StringJunky
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The only difference is the probability of decay. That what leads th the difference in lifetime. But the distribution is always an exponential decrease.

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The only difference is the probability of decay. That what leads th the difference in lifetime. But the distribution is always an exponential decrease.

The probability of each just happens to be that way? i have no problem with the inherent randomness and its exponential decay rate.

Edited by StringJunky

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