Does it really tick slower?

[YerniBoi]

So i had to write an essay on relativity and something's really bothering me: Why do I find every source saying "the moving clock ticks slower"? My issue is that i find it hard to believe that if time is dilated to it, then it should be moving it's mechanism slower. I think even though time is being dilated, it ticks just as fast as the stationary clock, when compared afterwards they show different times because the moving clock ticked for less time than the stationary clock and thus seems as if it ticked slower. Please someone tell me which one's right and why.

[imatfaal]

When your clock is viewed from a different frame which is in relative motion then the gap between each tick is lengthened. It is worth noting that when you look at the clock which you share a single frame with then you notice nothing unusual. Everything which has a time element: clock's ticking, hair growing, particles decaying, etc will be observed as going slower when observed from a separate frame which is in relative motion

[swansont]

So i had to write an essay on relativity and something's really bothering me: Why do I find every source saying "the moving clock ticks slower"? My issue is that i find it hard to believe that if time is dilated to it, then it should be moving it's mechanism slower. I think even though time is being dilated, it ticks just as fast as the stationary clock, when compared afterwards they show different times because the moving clock ticked for less time than the stationary clock and thus seems as if it ticked slower. Please someone tell me which one's right and why.

 

 

We have direct experimental evidence that the tick rate changes in relativity. The Pound-Rebka experiment was a frequency measurement, and GPS clocks have the frequency of their oscillator adjusted to make their output be consistent with earth-based time.

[Delta1212]

So i had to write an essay on relativity and something's really bothering me: Why do I find every source saying "the moving clock ticks slower"? My issue is that i find it hard to believe that if time is dilated to it, then it should be moving it's mechanism slower. I think even though time is being dilated, it ticks just as fast as the stationary clock, when compared afterwards they show different times because the moving clock ticked for less time than the stationary clock and thus seems as if it ticked slower. Please someone tell me which one's right and why.

You can see the moving clock the entire time. The only way it can tick for 5 minutes its time during the time you are watching it for 10 minutes your time is if it looks to you like it's moving at half the rate of "normal" time.

 

In its own frame, it obviously doesn't tick slower, less time has just passed, as you say.

[Tim88]

So i had to write an essay on relativity and something's really bothering me: Why do I find every source saying "the moving clock ticks slower"? My issue is that i find it hard to believe that if time is dilated to it, then it should be moving it's mechanism slower. I think even though time is being dilated, it ticks just as fast as the stationary clock, when compared afterwards they show different times because the moving clock ticked for less time than the stationary clock and thus seems as if it ticked slower. Please someone tell me which one's right and why.

 

First of all there is a matter of definitions. "ticking slower" commonly means that the number of ticks of that clock in a certain time period -as measured with a "stationary" reference system with clocks- is less than that of another clock:

"ticking slower" = "<number of ticks> / time of one clock is less than that of another clock".

And that is just what you are saying, is it not?

[Thorham]

The ticks don't change, it's local time itself that slows down... if I understand it correctly.

[imatfaal]

The ticks don't change, it's local time itself that slows down... if I understand it correctly.

 

Not sure you do. Local time - ie time within the observers frame of reference never slows down; relativity changes nothing within the observer's own frame.

 

But when a different frame of reference is viewed from a frame in relative motion then in the moving frame ( remember your frame is always stationary with respect to you) clocks will run slow and lengths will be contracted. And simplifying and ignoring lots of complicating factors the gap between each tick is lengthened when the clock is moving but the observer is stationary

[koti]

So i had to write an essay on relativity and something's really bothering me: Why do I find every source saying "the moving clock ticks slower"? My issue is that i find it hard to believe that if time is dilated to it, then it should be moving it's mechanism slower. I think even though time is being dilated, it ticks just as fast as the stationary clock, when compared afterwards they show different times because the moving clock ticked for less time than the stationary clock and thus seems as if it ticked slower. Please someone tell me which one's right and why.

You put 2 synchronised atomic clocks - one on a moving airplane and another one on earth - they will go out of synch. The mechanism on the airplane clock ticks slower but slower only in RELATION to the mechanism of the stationary clock which means that if you are standing on earth by the stationary clock you would "hear" the moving clock tick slower. Thats that I think.

 

Edit: So the answer to your question "Does it really tick slower?" is definitely yes. A stationary observer will hear a moving clock tick slower. Also look up "doppler effect" which might be useful as a refference to understand relativity.

Edited September 14, 2016 by koti

[swansont]

You put 2 synchronised atomic clocks - one on a moving airplane and another one on earth - they will go out of synch. The mechanism on the airplane clock ticks slower but slower only in RELATION to the mechanism of the stationary clock which means that if you are standing on earth by the stationary clock you would "hear" the moving clock tick slower. Thats that I think.

Edit: So the answer to your question "Does it really tick slower?" is definitely yes. A stationary observer will hear a moving clock tick slower. Also look up "doppler effect" which might be useful as a refference to understand relativity.

Careful. The earth isn't stationary, so it depends on which way the plane is going. A westbound plane is moving slower than the earth as measured by an inertial observer, so it ticks faster.

[koti]

Careful. The earth isn't stationary, so it depends on which way the plane is going. A westbound plane is moving slower than the earth as measured by an inertial observer, so it ticks faster.

 

You are undoubtedly right. Despite me omitting the fact that the earth is in motion I've also omitted the issue of impracticality of actually hearing the slower/faster ticking...or that a cesium clock doesn't give a ticking sound.

Nevertheless the answer to the OP's question is a Yes, wouldn't you agree ?

[swansont]

 

You are undoubtedly right. Despite me omitting the fact that the earth is in motion I've also omitted the issue of impracticality of actually hearing the slower/faster ticking...or that a cesium clock doesn't give a ticking sound.

Nevertheless the answer to the OP's question is a Yes, wouldn't you agree ?

 

 

Yes, absolutely. But if one were to look at the Hafele-Keating experiment (with clocks on planes), one might wonder why the westbound clocks ran fast, and there was the asymmetry between the two directions.

[koti]

 

 

Yes, absolutely. But if one were to look at the Hafele-Keating experiment (with clocks on planes), one might wonder why the westbound clocks ran fast, and there was the asymmetry between the two directions.

 

I'm having a slight fear of making an ass of myself in discussing this subject with a person who actualy builds atomic clocks but I will continue anyway

I don't wonder why there is an asymmetry of realitive time readings between the directions, it's pretty clear to me that the velocities are different in relation to each other therefore giving different, relative time readings. This is a very cool fact and thinking about it makes me grateful that I'm having an oportunity to live in an era when we already figured this stuff out. Nevertheless this is not the direct subject of the OP's original question...I think that his question consists of a very basic doubt that needed to be adressed in the simplest possible manner. At least that is what I would like if I was the OP.

 

Edit: And then theres gravity...

Edited September 15, 2016 by koti

[swansont]

 

I'm having a slight fear of making an ass of myself in discussing this subject with a person who actualy builds atomic clocks but I will continue anyway

I don't wonder why there is an asymmetry of realitive time readings between the directions, it's pretty clear to me that the velocities are different in relation to each other therefore giving different, relative time readings. This is a very cool fact and thinking about it makes me grateful that I'm having an oportunity to live in an era when we already figured this stuff out. Nevertheless this is not the direct subject of the OP's original question...I think that his question consists of a very basic doubt that needed to be adressed in the simplest possible manner. At least that is what I would like if I was the OP.

 

 

 

But you can't simplify it to the point that it's wrong. Your response would be correct if the earth were stationary, but it isn't.

[koti]

 

 

 

But you can't simplify it to the point that it's wrong. Your response would be correct if the earth were stationary, but it isn't.

 

I'm not sure I follow. I'm simplifying to show that the clocks realy do, physically, tick slower/faster. I'm not implying that anything is wrong, at least not on purpose.

As for the non-stationary earth...if I understand correctly nothing is stationary in the universe. Every object is moving in relation to some other object.

[swansont]

I'm not sure I follow. I'm simplifying to show that the clocks realy do, physically, tick slower/faster. I'm not implying that anything is wrong, at least not on purpose.

As for the non-stationary earth...if I understand correctly nothing is stationary in the universe. Every object is moving in relation to some other object.

You gave an example where the clock would not necessarily run slower. I was just pointing that out. The situation is not quite as simple as you described it.

 

I don't wonder why there is an asymmetry of realitive time readings between the directions, it's pretty clear to me that the velocities are different in relation to each other therefore giving different, relative time readings.

I've conversed with people for whom this was not clear at all, and simply repeated the mantra "moving clocks run slow" an concluded that relativity was wrong because a moving clock ran fast. No capacity for the fact that the issue was slightly more complex. That's why I added my caveat.

[koti]

You gave an example where the clock would not necessarily run slower. I was just pointing that out. The situation is not quite as simple as you described it.

 

 

You are right, that simplification I've made is crude and technicaly it is simply incorrect but I was trying to get my point across to the OP in the simplest manner. I'm simplifying to an extent where the relativistic effects are observalbe/measurable.

I have a question...if we were to measure time dilation efefcts on objects moving extremely slow in realtion to each other where the time relativistic effects would become shorter than the planck time frame would the time dilation effect exist or not or is this uncertain ?

 

I've conversed with people for whom this was not clear at all, and simply repeated the mantra "moving clocks run slow" an concluded that relativity was wrong because a moving clock ran fast. No capacity for the fact that the issue was slightly more complex. That's why I added my caveat.

Aren't we glad I'm not one of those people.

[swansont]

I have a question...if we were to measure time dilation efefcts on objects moving extremely slow in realtion to each other where the time relativistic effects would become shorter than the planck time frame would the time dilation effect exist or not or is this uncertain ?

 

It's moot. What we can measure is many orders of magnitude larger than the Planck time.

 

Aren't we glad I'm not one of those people.

Sure. But the comment wasn't so much for your edification as for anyone else reading the thread (such as the OP) who is not as familiar with relativity.

[koti]

 

It's moot. What we can measure is many orders of magnitude larger than the Planck time.

 

That is what I suspected. Thank you for the answer.

Edit: I presume the math colapses when explaining this issue with GR and extreme scales (excluding M theory which is the best we've got at the moment as far as I know)

Could you explain in layman's terms where the colapse/paradoxes lie ?

 

Sure. But the comment wasn't so much for your edification as for anyone else reading the thread (such as the OP) who is not as familiar with relativity.

 

You are right. I will try to combine more coherence into my simplifications in the future.

Edited September 15, 2016 by koti

[swansont]

It's moot. What we can measure is many orders of magnitude larger than the Planck time.

(doing most of this in my head early in the morning, so there may be math errors)

 

Planck time is of order of 10^-44 sec. So for motion in 1 sec, the fractional frequency shift has to be 10^-44, and this varies as v^2/c^2. So that's a speed of 10^-22c or a few fm per second. That's probably not realizable owing the Heisenberg Uncertainty Principle. Knowing an electrons's speed to that level gives a momentum of 10^-45 kg-m/sec^2. So its position can't be known to better than 10^11 meters

[koti]

(doing most of this in my head early in the morning, so there may be math errors)

 

Planck time is of order of 10^-44 sec. So for motion in 1 sec, the fractional frequency shift has to be 10^-44, and this varies as v^2/c^2. So that's a speed of 10^-22c or a few fm per second. That's probably not realizable owing the Heisenberg Uncertainty Principle. Knowing an electrons's speed to that level gives a momentum of 10^-45 kg-m/sec^2. So its position can't be known to better than 10^11 meters

 

That answers my question which I edited into my post while you were typing the above.

So i had to write an essay on relativity and something's really bothering me: Why do I find every source saying "the moving clock ticks slower"?

Because in essence that is a fact.

 

My issue is that i find it hard to believe that if time is dilated to it,then it should be moving it's mechanism slower.

You seem to misinterpret the time dilation concept. Time runs differently for different observers. Period.

 

I think even though time is being dilated, it ticks just as fast as the stationary clock,

Existence of the clock is submergerd in a relative time which runs different for different observers. One clock ticks slower than the other when observed by observer 1, it ticks faster when observed by observer 2, it ticks at the same rate when observed by observer 3, it ticks a lot slower when observed by observer 4 and so on.

 

when compared afterwards they show different times because the moving clock ticked for less time than the stationary clock

This is accurate. To be more precise I would add that "when compared afterwards they show different times because the moving clock ticked for less of its relative time than the stationary clock .

 

and thus seems as if it ticked slower. Please someone tell me which one's right and why.

There is no "seem" The clock physicaly ticked slower that the other clock.