Time Dilation

[steve_bank]

Time dilation has been demonstrated. Clocks carried on commercial jets compared with a reference clock on the ground agree with relativity within experimental error from the site on the experiment.

Two space ships at rest to each other, one accelerates to a constant relative velocity. On each ship a second by an atomic clock is still a second and a meter is still a meter.

Both ships by radar measure distance to the other ship . Both ships should agree on distance. C is constant. regardless of frame.

Clocks change but reality does not. C does not change. Two ships passing each other at difernt relative velocities do not transform or pass through anything different. Visual and radio communication do not change. The two ships are not in a different reality or dimension.

Numbers are in the link. Pretty close agreement with theory.

https://en.wikipedia.org/wiki/Hafele–Keating_experiment

The Hafele–Keating experiment was a test of the theory of relativity. In October 1971, Joseph C. Hafele, a physicist, and Richard E. Keating, an astronomer, took four cesium-beam atomic clocks aboard commercial airliners. They flew twice around the world, first eastward, then westward, and compared the clocks against others that remained at the United States Naval Observatory. When reunited, the three sets of clocks were found to disagree with one another, and their differences were consistent with the predictions of special and general relativity.

https://en.wikipedia.org/wiki/Time_dilation

Velocity time dilation[edit]

Special relativity indicates that, for an observer in an inertial frame of reference, a clock that is moving relative to him will be measured to tick slower than a clock that is at rest in his frame of reference. This case is sometimes called special relativistic time dilation. The faster the relative velocity, the greater the time dilation between one another, with the rate of time reaching zero as one approaches the speed of light (299,792,458 m/s). This causes massless particles that travel at the speed of light to be unaffected by the passage of time.

 

[fast]

What if time dilation is an actual phenomenon but the term itself is a misnomer? If there is a dilation of sorts that’s being referred to yet time remains unaffected, then while time dilation is real, there is no dilation of time. Maybe an analogy is in order. If a lie is the utterance of a falsehood with the intent to deceive, then a lie by omission isn’t a lie. The term itself would thus be a misnomer and lead poor unsuspecting readers to think a lie by omission is a type of lie.

At its core, what I’m suggesting is that while science might have nailed down the truth about time dilation, there is a competing conception of time that ought not be interchanged. One conception allows “quasi-infinite” as a description. The idea is that the Big Bang marked the beginning of time rendering any notion of “before the Big Bang” as nonsensical.

 

[Speakpigeon]

Strictly speaking, there is no time dilatation at all since in Relativity time is what is measured by the clock. All you can say is that there will be a mismatch between two different clocks if the two clocks are in relative motion, or if they are subjected to different intensities of gravity, whatever that is.

There are many competing views of General Relativity, and in particular, you have models with a flat spacetime and models with a curved spacetime. As I understand it, the notion of the dilatation of time would be realistic only in a flat spacetime. Broadly, it's either the spacetime or our spatial and temporal measures that "curve". But which model is true of the real world?

And, obviously, these are only models. Abstractions. Time exists or it doesn't. Who will really know?

Now, if there are people here who are experts on "bi-metric gravitation", or on the "field-theoretical approach to general relativity", you're invited to lecture us.
EB

 

[fast]

Strictly speaking, there is no time dilatation at all since in Relativity time is what is measured by the clock. All you can say is that there will be a mismatch between two different clocks if the two clocks are in relative motion, or if they are subjected to different intensities of gravity, whatever that is.

Time is measured by the clock, but it’s not a direct measurement. It’s an indirect or secondary measurement. What we’re directly measuring is a proxy for time. When the instruments deviate, that’s not time dilating but rather the proxy diverging from time.

 

[DBT]

Physical processes work at different rates under different conditions, gravity, velociy, and it is the given rate of change that we call time?

 

[none]

i don;t get it
take a path vertical and then move it
two paths are evident from two different positions
one path is a triangle up and another path is strictly vertical
hypotenuse is longer than the vertical segment...
wtf happened?

 

[Speakpigeon]

Strictly speaking, there is no time dilatation at all since in Relativity time is what is measured by the clock. All you can say is that there will be a mismatch between two different clocks if the two clocks are in relative motion, or if they are subjected to different intensities of gravity, whatever that is.

Time is measured by the clock, but it’s not a direct measurement. It’s an indirect or secondary measurement. What we’re directly measuring is a proxy for time. When the instruments deviate, that’s not time dilating but rather the proxy diverging from time.

As I see it, it all comes down to our impression that natural events occur with an intrinsic regularity, first and foremost the movement of the Sun around the Earth. This leads us to assume the metaphysical construct of time. By metaphysical here, I mean something we think is physical but that we cannot perceive as such, like we do pain, colours and shape for example. We can't measure time if by time we mean this sort of metaphysical construct.

That being said, man is the measure of all things. How could we have any notion of the temporal regularity of events if we didn't have in fact some kind of perception of time, or at least of something like time, something which is usually called "subjective time". Obviously, subjective time isn't too reliable since the notion itself suggests it is affected by psychological factors. Yet, there is little doubt that subjective time is our reference for assessing that natural events occur regularly.

Does any of this proves time exists as such? Not really. We can conceive of natural processes as having their own local rate of occurrence. Natural process occur essentially at the microscopic level. So, we can assume the rate of occurrence at the microscopic level to be foundational to time. "SI defines the second as 9,192,631,770 cycles of the radiation that corresponds to the transition between two electron spin energy levels of the ground state of the ¹³³Cs atom (Wiki)". This seems to give ontological consistence to time.

Yet, if we accept that the human mind is essentially a natural process, then it is very likely that our sense of time is based on the same sort of microscopic events as used in measuring time. It seems reasonable then to assume a common factor, which may well be time itself, but that could just as well be something else, something unlike what we usually think of as time, for example a sort of microstructure of reality affecting similarly our brain processes and electronic transitions in caesium atoms. You may want to call such a microstructure, of whatever would play the same role, as time itself. Maybe scientists uncovering this microstructure will say they have discovered time or the nature of time. Yet, it would certainly be something very different from what most people seem to have in mind when they think of time.

A crucial aspect to this idea is that such a microstructure makes our idea of time completely redundant. Reality would be utterly void of time. Instead, the microstructure itself would somehow trigger all events at the microscopic scale, providing a sort of universal regularity to natural processes. We can think of this as a variation on the notion of block universe. Here, instead of a growing block of events, we would have an unchanging block of events. It's a bit of a disturbing perspective but it is a logical possibility.

In this perspective, a clock follows the microstructure just as our brain does. Measuring time with a clock would be essentially providing a more convenient sequencing of our perception of the microstructure. A kind of measure, not of the microstructure itself, since we don't really care about it given that we don't even know it exists, but a measure more like a way to cadence and synchronise the various activities of all human beings. A mere convenience, somewhat like the bells of the local church to tell people when to do things. In this perspective, time, objective time, the thing supposedly measured by clocks, is a social construct, from which is derived time as a scientific concept.

Clocks don't measure time. They tell time.

Show

Well, at least it's a logical possibility.

Show

Copernicus, what do you think?

EB

 

[Jimmy Higgins]

Strictly speaking, there is no time dilatation at all since in Relativity time is what is measured by the clock. All you can say is that there will be a mismatch between two different clocks if the two clocks are in relative motion, or if they are subjected to different intensities of gravity, whatever that is.

Time is measured by the clock, but it’s not a direct measurement. It’s an indirect or secondary measurement. What we’re directly measuring is a proxy for time. When the instruments deviate, that’s not time dilating but rather the proxy diverging from time.

As I see it, it all comes down to our impression that natural events occur with an intrinsic regularity, first and foremost the movement of the Sun around the Earth. This leads us to assume the metaphysical construct of time. By metaphysical here, I mean something we think is physical but that we cannot perceive as such, like we do pain, colours and shape for example. We can't measure time if by time we mean this sort of metaphysical construct.

That being said, man is the measure of all things. How could we have any notion of the temporal regularity of events if we didn't have in fact some kind of perception of time, or at least of something like time, something which is usually called "subjective time". Obviously, subjective time isn't too reliable since the notion itself suggests it is affected by psychological factors. Yet, there is little doubt that subjective time is our reference for assessing that natural events occur regularly.

Does any of this proves time exists as such? Not really. We can conceive of natural processes as having their own local rate of occurrence. Natural process occur essentially at the microscopic level. So, we can assume the rate of occurrence at the microscopic level to be foundational to time. "SI defines the second as 9,192,631,770 cycles of the radiation that corresponds to the transition between two electron spin energy levels of the ground state of the ¹³³Cs atom (Wiki)". This seems to give ontological consistence to time.

Yet, if we accept that the human mind is essentially a natural process, then it is very likely that our sense of time is based on the same sort of microscopic events as used in measuring time. It seems reasonable then to assume a common factor, which may well be time itself, but that could just as well be something else, something unlike what we usually think of as time, for example a sort of microstructure of reality affecting similarly our brain processes and electronic transitions in caesium atoms. You may want to call such a microstructure, of whatever would play the same role, as time itself. Maybe scientists uncovering this microstructure will say they have discovered time or the nature of time. Yet, it would certainly be something very different from what most people seem to have in mind when they think of time.

A crucial aspect to this idea is that such a microstructure makes our idea of time completely redundant. Reality would be utterly void of time. Instead, the microstructure itself would somehow trigger all events at the microscopic scale, providing a sort of universal regularity to natural processes. We can think of this as a variation on the notion of block universe. Here, instead of a growing block of events, we would have an unchanging block of events. It's a bit of a disturbing perspective but it is a logical possibility.

In this perspective, a clock follows the microstructure just as our brain does. Measuring time with a clock would be essentially providing a more convenient sequencing of our perception of the microstructure. A kind of measure, not of the microstructure itself, since we don't really care about it given that we don't even know it exists, but a measure more like a way to cadence and synchronise the various activities of all human beings. A mere convenience, somewhat like the bells of the local church to tell people when to do things. In this perspective, time, objective time, the thing supposedly measured by clocks, is a social construct, from which is derived time as a scientific concept.

Clocks don't measure time. They tell time.

What? It is like you don't understand anything about time dilation.

 

[Loren Pechtel]

i don;t get it
take a path vertical and then move it
two paths are evident from two different positions
one path is a triangle up and another path is strictly vertical
hypotenuse is longer than the vertical segment...
wtf happened?

The point is the up-down motion is at lightspeed. Moving horizontally doesn't change that fact--the observer must still see the vertical movement at lightspeed as that is an invariant. In a Newtonian world you see faster-than-light motion. What Einstein realized is that everything works out if the yardsticks you're measuring with change with velocity. The bouncing path is normally used as an illustration of the slowing of time but in reality you need to alter time, length and mass to keep everything balanced. The math of special relativity is no big deal, the important aspect is the realization of what's going on.

 

[Speakpigeon]

What? It is like you don't understand anything about time dilation.

Here is the bare-bones of what I understand...

According to the theory of relativity, time dilation is a difference in the elapsed time measured by two observers, either due to a velocity difference relative to each other, or by being differently situated relative to a gravitational field. As a result of the nature of spacetime, a clock that is moving relative to an observer will be measured to tick slower than a clock that is at rest in the observer's own frame of reference. A clock that is under the influence of a stronger gravitational field than an observer's will also be measured to tick slower than the observer's own clock.
https://en.wikipedia.org/wiki/Time_dilation

Not enough?

OK, I understand that too:

Such time dilation has been repeatedly demonstrated, for instance by small disparities in a pair of atomic clocks after one of them is sent on a space trip, or by clocks on the Space Shuttle running slightly slower than reference clocks on Earth, or clocks on GPS and Galileo satellites running slightly faster.

Still not enough?

OK, I understand that too:

Special relativity indicates that, for an observer in an inertial frame of reference, a clock that is moving relative to him will be measured to tick slower than a clock that is at rest in his frame of reference. This case is sometimes called special relativistic time dilation. The faster the relative velocity, the greater the time dilation between one another, with the rate of time reaching zero as one approaches the speed of light (299,792,458 m/s). This causes massless particles that travel at the speed of light to be unaffected by the passage of time.

Observe that time dilatation is not the dilatation of time itself but the difference between two clocks.

For this reason, what I say is perfectly compatible with time dilatation.

It is like you don't understand anything about what I said about time.
EB

 

[skepticalbip]

... snip ...

Observe that time dilatation is not the dilatation of time itself but the difference between two clocks.

... snip ...

That is like saying that the difference between someone who is 160 cm tall in Sweden and someone 180 cm tall in Australia is the length of the meter sticks used to measure them.

 

[Gun Nut]

... snip ...

Observe that time dilatation is not the dilatation of time itself but the difference between two clocks.

... snip ...

That is like saying that the difference between someone who is 160 cm tall in Sweden and someone 180 cm tall in Australia is the length of the meter sticks used to measure them.

OR.. Maybe... it is more like saying that it takes 10 minutes to boil a liter of water in Sweden and 8 minutes to boil a liter of water in Australia... and that is due to ambient pressure. What is the ambient pressure that drives time, and where does that pressure differ.. and why?

 

[skepticalbip]

... snip ...

Observe that time dilatation is not the dilatation of time itself but the difference between two clocks.

... snip ...

That is like saying that the difference between someone who is 160 cm tall in Sweden and someone 180 cm tall in Australia is the length of the meter sticks used to measure them.

OR.. Maybe... it is more like saying that it takes 10 minutes to boil a liter of water in Sweden and 8 minutes to boil a liter of water in Australia... and that is due to ambient pressure. What is the ambient pressure that drives time, and where does that pressure differ.. and why?

That is a poor analogy. Speakpigeon is saying that the measurement device itself is the problem. His description would mean that water in both parts of the world take the same amount of time to boil but the clocks read differently. That it is the clocks themselves that are effected not what they are measuring.

 

[steve_bank]

That is the question, unproven as far as I know. The inference is that because clocks run differently all processes vary with time dilation.

A sand hourglass clock or an electronic clock are both subject to dilation.

 

[skepticalbip]

That is the question, unproven as far as I know. The inference is that because clocks run differently all processes vary with time dilation.

A sand hourglass clock or an electronic clock are both subject to dilation.

So is muon decay.

Using the same clock in our reference frame the muon will take longer and longer (with respect to our time frame) to decay the faster and faster it is moving with respect to our reference frame.

 

[steve_bank]

The experiment in the link used atomic clocks. Counting particle radiation.

 

[Speakpigeon]

OR.. Maybe... it is more like saying that it takes 10 minutes to boil a liter of water in Sweden and 8 minutes to boil a liter of water in Australia... and that is due to ambient pressure. What is the ambient pressure that drives time, and where does that pressure differ.. and why?

That is a poor analogy. Speakpigeon is saying that the measurement device itself is the problem.

???

Whoa.

Speakpigeon is saying that the measurement device itself is the problem?!

Gosh.

I didn't know I was saying that the measurement device itself is the problem.

I thought I was saying something else altogether...

Like, "Observe that time dilatation is not the dilatation of time itself but the difference between two clocks".

And this in fact is a fact, like, a factual fact. I understand you're not too good at science but your English also sucks. Or is it that you have a bias each time your have to interpret what this fucking nitwit Speakpigeon is saying?

Observe that your on-record inability to understand the words of Speakpigeon is entirely due to yourself.

Please, just have a look at this and see if you can interpret the following as saying that "the measurement device itself is the problem":

Time dilation
According to the theory of relativity, time dilation is a difference in the elapsed time measured by two observers, either due to a velocity difference relative to each other, or by being differently situated relative to a gravitational field. As a result of the nature of spacetime, a clock that is moving relative to an observer will be measured to tick slower than a clock that is at rest in the observer's own frame of reference. A clock that is under the influence of a stronger gravitational field than an observer's will also be measured to tick slower than the observer's own clock.
https://en.wikipedia.org/wiki/Time_dilation

And I promise it's not me who wrote this piece.
EB

 

[skepticalbip]

... snip ...

Time dilation
According to the theory of relativity, time dilation is a difference in the elapsed time measured by two observers, either due to a velocity difference relative to each other, or by being differently situated relative to a gravitational field. As a result of the nature of spacetime, a clock that is moving relative to an observer will be measured to tick slower than a clock that is at rest in the observer's own frame of reference. A clock that is under the influence of a stronger gravitational field than an observer's will also be measured to tick slower than the observer's own clock.
https://en.wikipedia.org/wiki/Time_dilation

And I promise it's not me who wrote this piece.
EB

Although the Wiki quote is correct it is poorly stated (Wiki is hardly the first source anyone should rely on). But even given that, you either misunderstood it or your post was even more poorly stated.

Time dilation has nothing to do with clocks. The clocks are only used to measure and demonstrate the time dilation. Just as meter sticks have nothing to do with someone's height, they are only used to measure that height.

To remind you of your idiotic post....

... snip ...

Observe that time dilatation is not the dilatation of time itself but the difference between two clocks.

... snip ...

That is hardly what the Wiki text said.

 

[Speakpigeon]

If time was the occurrence of an event, or the succession of events, there would be no reason for similar processes to take the same amount of time.

Instead, if you think events occur in time, in some sort of preexisting time, then events will take a certain time to unfold according to their nature.

Unless, if there is just one fundamental type of event. The time for a macroscopic event to unfold would depend on the fundamental events it is made of. In fact, I can't see any other explanation.

This explains clocks without having to resort to the metaphysical concept of time.

Show

I think Einstein would have liked this.

EB

 

[Speakpigeon]

Although the Wiki quote is correct it is poorly stated (Wiki is hardly the first source anyone should rely on). But even given that, you either misunderstood it or your post was even more poorly stated

Then rephrase it for us.

Time dilation has nothing to do with clocks.

I didn't say that or even suggest it.

I only said that your English sucks.

I said that time dilatation is not the dilatation of time itself but the difference between two clocks.

Prove me wrong if you can.

The clocks are only used to measure and demonstrate the time dilation.

Then prove time dilatation. But first, prove the existence of time...

To remind you of your idiotic post....

Observe that time dilatation is not the dilatation of time itself but the difference between two clocks.

That is hardly what the Wiki text said.

Then explain the difference. Prove to me that the difference between the two clocks is due to something like the dilation of an ontologically real time rather than some other physical causes. But start by proving that time exists as such to begin with.

It's clear you don't even understand what the problem is.
EB