Does velocity really dilate time?

[Uclock]

Yorda

i doubt he seriously thought that things have weight because "spacetime" is distorted. space can't be distorted because it doesn't consist of anything. magnetism doesn't distort space+time, so why would gravity. they're the same thing.

I think you will find Einstein believed quite correctly that gravity is a distortion of spacetime. We only have weight because of our mass and gravity. Outside of the gravitational field we have just mass. Space is not ‘nothing’ it has dimensions and without these dimensions there can be no movement. Magnetism and gravity are different they are not the exactly the same thing.
In free space, lets say where all the gravitational fields are balanced such as at one of Lagrangian points, it will take an unbalanced force to move an object and the object will feel this force but in a gravitational field an object moves not because an unbalanced force acts on it but because spacetime is distorted and it will feel nothing whilst it is in free fall.

Tony

 

[Uclock]

Farsight

Uclock: acceleration doesn't cause time dilation. Really. You can understand this if you run the Twin's Paradox thought-experiment twice over. On the first run twin A travels for one light year before he turns back. On the second run twin A travels for two light years before he turns back. In both cases the acceleration is the same, the only difference is the duration of the coasting phase. And this is what determines the differential ages of the twins.

I think you might need to revisit the twin experiment. Only one twin goes off into space whilst the other remains on Earth. Let say twin A takes the trip into space and twin B remains on Earth. First of all twin A has to undergo acceleration to reach his cruising velocity where he is in uniform motion. He has relative velocity to the frame of his twin, twin B. According to the frame of twin A in space, twin B will have relative velocity to his frame. Both have relative velocity to one another, so if time dilates for one it also dilates for the other.
When twin A reaches the end point of his journey he has to decelerate to a standstill relative to twin B’s frame then accelerate back in the direction of Earth until he reaches his cruising velocity where once again he is in uniform motion. As he approaches Earth he has to decelerate until he lands on the Earth. The point with this thought experiment is there are four sections of acceleration involved for twin A and none for twin B who remained at home on Earth. IMHO it is these moments of acceleration that cause time dilation, unless of course you view spacetime as a metric as Einstein did in which case it makes sense that velocity accounts for time dilation.

What actually causes this time dilation is a change in c. We can never measure c to be anything other than 300,000km/s. Hence we tend to think of c as a rock-solid constant. But when you understand relativity to the full, and realise how light defines our distance and our time, you will understand that c is not in truth an absolute constant at all. The twin who aged less aged less because his c was lower than that of his twin, but he didn't notice it. See TIME EXPLAINED and GRAVITY EXPLAINED for details.

The velocity of light in a vacuum which is 299792458m s^-1 will never change no matter how fast an object is moving when it observes light. Pastafarian is correct, your view of relativity is wrong and you need to study it more. Your essays are not physics because you cannot back them up with any math.

Others here may beg to differ. They can assert that I'm wrong, but they cannot prove me wrong. I dare say that at some point in the future some of them will be teaching this in schools. I imagine it will be called Relativity++. And that's what you call a challenge.

Try and use your essays to equal what we know to be true about gravity such as by mathematically matching Newtonian gravity within the confines of the solar system. If you can do that then perhaps people will listen and I don’t wish to sound harsh but up until now all you have is a load of words pointing out your view of reality. It is not physics.

Tony

 

[Yorda]

I think you will find Einstein believed quite correctly that gravity is a distortion of spacetime.

then i guess he was a pretty big Idiot.

Space is not ‘nothing’ it has dimensions and without these dimensions there can be no movement.

only objects which consist of something can have dimensions. and dimensions are just abstractions, thoughts.

Magnetism and gravity are different they are not the exactly the same thing.

just like red and blue are different, yet they're parts of the same light.

 

[Uclock]

Yorda

“Originally Posted by Uclock
I think you will find Einstein believed quite correctly that gravity is a distortion of spacetime.”

then i guess he was a pretty big Idiot.

I think calling one of the best minds in the last century an idiot means that you are calling the whole of the physics community idiots. Einstein’s theories of relativity have stood the test of time.
I am not saying his view of spacetime as a metric is correct but it must be close to have withstood experimentation to the level it has. He was far from an idiot. The results of the biggest test of GR ever undertaken are due next month, that of the Gravity Probe ‘B’ experiment, and this is the test I have been waiting for because I believe the value for frame dragging will be higher than expected by GR.

“Space is not ‘nothing’ it has dimensions and without these dimensions there can be no movement.”

only objects which consist of something can have dimensions. and dimensions are just abstractions, thoughts.

Dimensions are real not abstract.

“Magnetism and gravity are different they are not the exactly the same thing.”

just like red and blue are different, yet they're parts of the same light.

Not quite. To what level have you studied physics or are you just making it up as you go along?

Tony

 

[Farsight]

Farsight, I think you might need to revisit the twin experiment... IMHO it is these moments of acceleration that cause time dilation, unless of course you view spacetime as a metric as Einstein did in which case it makes sense that velocity accounts for time dilation.

Sorry Tony, I've studied this. It's definitely not the acceleration that causes the time dilation. See my earlier post about running the Twins experiment twice. Yes there's a symmetry which is broken by the acceleration via a shift in "now", but the time dilation is happening during the coasting phase. The logic of this is clear if you look at the length of the coasting phase in the two runs, both of which have identical accelerations.

It was Minkowski who introduced spacetime, Einstein was very unhappy about it at the time, was happy again when formulating General Relativity, but had doubts again later in life. As for how deep these doubts were I can't be sure, but I think they were more serious than is generally appreciated. The telling phrase is "Is Spacetime a Space?".

The velocity of light in a vacuum which is 299792458m s^-1 will never change no matter how fast an object is moving when it observes light. Pastafarian is correct, your view of relativity is wrong and you need to study it more. Your essays are not physics because you cannot back them up with any math.

The measured velocity of light is always the same because light defines distance and time. Look up the definition of the second and the metre on google. We think of time dilation as being countered by length contraction, but a transverse metre rule is not length contracted. If you're travelling at .99c with respect to me it will take your light beam seven times as long to traverse an identical transverse metre. Yes there's the symmetry again, but you and I could count and compare the number of traverses during your "Twins" round trip. The only way that you experiences fewer traverses than me is if your c is reduced with respect to mine. That's why you come back younger. I'm sorry, but Pastafarian is naive, and he uses specious arguments because he lacks the intellectual capacity to tackle the subject.

My essays are mathematics-lite because I'm explaining mathematical axioms. These are the things like t, E, and m that you take for granted. Mathematics cannot explain the axioms upon which it is built, an observation that is related to Godel's Theorem. If you'd read TIME EXPLAINED v2.1 you would know why I mention his name, and if you give it enough thought, you might one day appreciate why these essays are most definitely physics. I'd go so far as to say they're groundbreaking, so please do read them thoroughly and give them your serious consideration. Please don't respond with something I've already dealt with in an essay unless you can point out my error, whereupon I'll be disappointed, but pleased to receive earnest intelligent feedback.

PS: I certainly don't think Einstein was a fool. That's why this is Relativity++.

 

[(Q)]

The only way that you experiences fewer traverses than me is if your c is reduced with respect to mine. That's why you come back younger.

Complete rubbish. Unless light is going through a medium or you change the properties of spacetime, it ain't gonna happen, numbnuts.

I'm sorry, but Pastafarian is naive, and he uses specious arguments because he lacks the intellectual capacity to tackle the subject.

Specious arguments=experimental results.

My essays are mathematics-lite because I'm explaining mathematical axioms.

You're talking gibberish.

If you'd read TIME EXPLAINED v2.1 you would know why I mention his name

Kooks always drop names in hope of getting attention.

and if you give it enough thought, you might one day appreciate why these essays are most definitely physics.

Handwaving, without the use of hands.

I'd go so far as to say they're groundbreaking

Hahahaha! More like wind breaking.

Please don't respond with something I've already dealt with in an essay unless you can point out my error, whereupon I'll be disappointed, but pleased to receive earnest intelligent feedback.

Translation: agree with me or else I'll throw a hissy fit.

 

[Votorx]

C isn't constant?
Hmm... well I thought C depicts the speed of light in a vacuum.
If the speed of light in a vacuum isn't constant...well then that would mean that if I ran at 4 miles an hour Im making light go slower relative to me! That doesn't seem right though...because I thought the paradox that arose with einstein was due to the fact that light WAS constant and therefore didn't follow the laws of relative motion... Well then I guess physics is wrong since light is infact NOT constant.

But if you undergo time dilation, your seconds are different so your c, the c that defines your seconds, must be different too. It's crushingly simple.

C defines our seconds? Personally I thought seconds, minutes, hours, days, weeks, months, years etc. etc. arose from planetary motion and orbit. I mean, how can it not? Unless you suggest the speed of light was used to define time even before c was defined. Those ancients must have been really really really really really smart then.

But lets say you do go through time dilation. Your passage through time is different RELATIVE to an observer going at a different velocity. But to you, personally, a second is still a second. To the observer, a second is still a second, therefore c remains unchanged because measurments in change is just that, a measurment. A concept created by us to effectively MEASURE different aspects of nature, no more, no less.

Your suggesting the observer can explain the traveler's perception of time as if it was as physical as the traveler's motion. Unfortunately, he can only effectively explain its motion through time by comparing it to his own and he does using measurements.

 

[kwhilborn]

Gravitational time dilation and Velocity time dilation are the same thing. The faster you travel, the more mass you have (yet you'll appear skinnier; go figure). The more mass you have the more gravity. This is what Uclock was arguing against in the centrifuge experiment. The faster moving guy would have more mass hence more gravity. The faster you go the more your mass, and clocks will seem to slow down to a relative observer.

Farsight commented that c can differ from perspectives, but c cannot change from perspectives, it is always c, and that was the question that inspired the T.S.R., but nonetheless not applicable. Sorry Farsight

So the only real non-velocity time dilation must occur by spacing yourself from mass.

The GPS clocks (as given by Q) / or other spacefaring satellite clocks are the only correct answers I can see so far.

There do seem to be other definitions of time dilation other than T.S.R. ones. Some teachers, etc (if this is homework), may be looking for an answer like
"the suitcase in the train" thing. here
http://www.kinkel-bischem.de/kosmologie/engzyklentheorie5.html
it is based on observation and not relativity theories, kind of like the doppler effect. I think wikipedias definition is an observation effect as well. Just in case we are messing up someones homework assignment. lol

 

[Farsight]

Votorx: this is the definition of the second:

Under the International System of Units, the second is currently defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. This definition refers to a caesium atom at rest at a temperature of 0K…

The second is defined in terms of periods of radiation. Radiation is light. If we had some change of condition that affected the period of this radiation, this would affect our seconds. Our seconds would be longer seconds, but we wouldn't know it because that change of condition would similarly effect every atom in our bodies, and in our clocks, and in our rulers. Now look at the definition of the metre:

The metre is the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second...

Not only would we have different seconds, but we would also have different metres, by definition. And again this would affect every atom in our bodies, and in our clocks, and in our rulers. But look at the definitions again. We will still measure c at 300,000km/s. PS: there is no "passage through time". Your passage is through space. See TIME EXPLAINED v2.1 for details. And take note of this quote:

"In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position. Now we might think that as a consequence of this, the special theory of relativity and with it the whole theory of relativity would be laid in the dust. But in reality this is not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity ; its results hold only so long as we are able to disregard the influences of gravitational fields on the phenomena (e.g. of light)." Albert Einstein (The General Theory of Relativity: Chapter 22 - A Few Inferences from the General Principle of Relativity)

kwilborn: there's been much debate in physics about rest mass and relativistic mass. Personally I favour the latter. And while there is a parallel between relativistic time dilation and gravitational time dilation, the two are not equivalent. You do not "have more gravity" if you travel fast. See MASS EXPLAINED and GRAVITY EXPLAINED for details.

 

[Uclock]

Farsight

Sorry Tony, I've studied this. It's definitely not the acceleration that causes the time dilation. See my earlier post about running the Twins experiment twice. Yes there's a symmetry which is broken by the acceleration via a shift in "now", but the time dilation is happening during the coasting phase. The logic of this is clear if you look at the length of the coasting phase in the two runs, both of which have identical accelerations.

This is only a thought experiment and if you run the thought experiment twice and have a longer uniform motion phase in one run than the other how do you know for definite that there will be a greater time dilation unless you conclude that velocity is responsible for time dilation and not acceleration then both twins have a velocity relative to each other. That is the reason why it is called the twin paradox.

It was Minkowski who introduced spacetime, Einstein was very unhappy about it at the time, was happy again when formulating General Relativity, but had doubts again later in life. As for how deep these doubts were I can't be sure, but I think they were more serious than is generally appreciated. The telling phrase is "Is Spacetime a Space?".

Einstein admitted he had no idea what space was, here is an extract in his own words:
In Special Relativity Part III, [1] Einstein states:
“In the first place, we entirely shun the vague word “space” of which, we must honestly acknowledge we cannot form the slightest conception, and we replace it by “motion relative to a practically rigid body at reference.”

He also looked at the arrow of time as the mind creating order so he considered it as a psychological effect. The point of this thread is there is no real hard evidence that velocity causes time dilation. Any experiment on time dilation involves a certain amount of acceleration which is unavoidable therefore the possibility that it is only the acceleration portion of any experiment that is responsible for time dilation, always exists.

The measured velocity of light is always the same because light defines distance and time. Look up the definition of the second and the metre on google. We think of time dilation as being countered by length contraction, but a transverse metre rule is not length contracted. If you're travelling at .99c with respect to me it will take your light beam seven times as long to traverse an identical transverse metre. Yes there's the symmetry again, but you and I could count and compare the number of traverses during your "Twins" round trip. The only way that you experiences fewer traverses than me is if your c is reduced with respect to mine. That's why you come back younger. I'm sorry, but Pastafarian is naive, and he uses specious arguments because he lacks the intellectual capacity to tackle the subject.

If I never bothered to learn physics and had to keep looking up definitions of units then would not try and discuss physics with people who have. I don’t disagree with velocity causing time dilation if you view spacetime as a metric as Einstein did but there is an alternative and it is this alternative that I am exploring.
I am new to this website so I cannot comment on Pastafarian’s level of knowledge but if I agree with him then I will say so.

My essays are mathematics-lite because I'm explaining mathematical axioms. These are the things like t, E, and m that you take for granted. Mathematics cannot explain the axioms upon which it is built, an observation that is related to Godel's Theorem. If you'd read TIME EXPLAINED v2.1 you would know why I mention his name, and if you give it enough thought, you might one day appreciate why these essays are most definitely physics. I'd go so far as to say they're groundbreaking, so please do read them thoroughly and give them your serious consideration. Please don't respond with something I've already dealt with in an essay unless you can point out my error, whereupon I'll be disappointed, but pleased to receive earnest intelligent feedback.

PS: I certainly don't think Einstein was a fool. That's why this is Relativity++.

You are just putting your view of the mathematical axioms and everyone is entitled to a view but without following up this view with extra math to solidify your perspective of reality then how do you expect physicists to take notice?
I have read your essays and they do nothing for me so I would like to ask you, to what level have you studied physics?

You are right, Einstein was most definitely not a fool, only an idiot would say such a thing.

Tony

 

[w1z4rd]

// Useless info

It takes me 10 min to get through a 10 page religious thread with a relevant reply, it took me an hour and a half to get through this thread and a real lot of help from wiki. I still do not have a relevant reply

 

[Farsight]

Farsight, this is only a thought experiment and if you run the thought experiment twice and have a longer uniform motion phase in one run than the other how do you know for definite that there will be a greater time dilation unless you conclude that velocity is responsible for time dilation and not acceleration then both twins have a velocity relative to each other. That is the reason why it is called the twin paradox.

Because I understand time. Time dilation is like perspective. If we're separated by distance I look smaller to you and you look smaller to me. If we're separated by velocity your time looks smaller to me and mine looks smaller to you. If you spend a short period away from me while your time looks smaller, and then come back, the resultant difference in our ages is modest. If you spend a long period away from me while your time looks smaller and then come back, the difference in our ages is greater, even though in both these cases the accelerations were the same.

Einstein admitted he had no idea what space was, here is an extract in his own words: In Special Relativity Part III, [1] Einstein states: “In the first place, we entirely shun the vague word “space” of which, we must honestly acknowledge we cannot form the slightest conception, and we replace it by “motion relative to a practically rigid body at reference.”

Fair enough, but his views did evolve over the years, and you shouldn't take that as his final view. Have a google on Einstein and Godel in Princeton in about 1949.

He also looked at the arrow of time as the mind creating order so he considered it as a psychological effect. The point of this thread is there is no real hard evidence that velocity causes time dilation. Any experiment on time dilation involves a certain amount of acceleration which is unavoidable therefore the possibility that it is only the acceleration portion of any experiment that is responsible for time dilation, always exists.

Again, fair enough. But I do think you're wrong about the lack of hard evidence. There have been long flights with atomic clocks, centrifuge experiments, there's GPS, and Nasa missions. With the understanding of relativity that abounds along with my own concepts, that's enough for me to assert that you've got the wrong idea.

If I never bothered to learn physics and had to keep looking up definitions of units then would not try and discuss physics with people who have. I don’t disagree with velocity causing time dilation if you view spacetime as a metric as Einstein did but there is an alternative and it is this alternative that I am exploring. I am new to this website so I cannot comment on Pastafarian’s level of knowledge but if I agree with him then I will say so.

No problem. It's good to talk.

You are just putting your view of the mathematical axioms and everyone is entitled to a view but without following up this view with extra math to solidify your perspective of reality then how do you expect physicists to take notice?

I expect them to show some interest. I don't expect them to say there's no maths so that's not physics. That's like saying there's no French so that's not English. It's a false premise used for dismissal and clinging to current concepts. Physics shouldn't be like that. It should be open, rational, exploring. I also expect physicists to appreciate that a postulate (or an axiom) is very different to explanation. Einstein postulated that c is always measured to be the same value, I can explain why.

I have read your essays and they do nothing for me so I would like to ask you, to what level have you studied physics?

I challenge that. I don't think you'd be asserting that acceleration causes time dilation if you'd read TIME EXPLAINED or GRAVITY EXPLAINED. But OK, if you've skimmed them briefly because they don't attract you, that's something I should look at. My formal physics education ended at A-level, and I've done private reading over twenty-something years. Yes, I'm an outsider, an amateur. I have a Computer Science degree and work as an IT Manager. Perhaps the most useful aspect of my skillset has been the Systems Analysis.

 

[Uclock]

Farsight

Because I understand time. Time dilation is like perspective. If we're separated by distance I look smaller to you and you look smaller to me. If we're separated by velocity your time looks smaller to me and mine looks smaller to you. If you spend a short period away from me while your time looks smaller, and then come back, the resultant difference in our ages is modest. If you spend a long period away from me while your time looks smaller and then come back, the difference in our ages is greater, even though in both these cases the accelerations were the same.

Do you really understand time? If so can you explain time’s arrow, why time has a direction, why we have a past and why the future is not set in stone? Do you think it is a psychological process as Einstein did or do you think time’s arrow should have a real explanation in physics?

“Einstein admitted he had no idea what space was, here is an extract in his own words: In Special Relativity Part III, [1] Einstein states: “In the first place, we entirely shun the vague word “space” of which, we must honestly acknowledge we cannot form the slightest conception, and we replace it by “motion relative to a practically rigid body at reference.” ”

Fair enough, but his views did evolve over the years, and you shouldn't take that as his final view. Have a google on Einstein and Godel in Princeton in about 1949.

His views may have evolved over the years but time’s arrow is the one physical problems he never tackled, because he thought of it as psychological.

“He also looked at the arrow of time as the mind creating order so he considered it as a psychological effect. The point of this thread is there is no real hard evidence that velocity causes time dilation. Any experiment on time dilation involves a certain amount of acceleration which is unavoidable therefore the possibility that it is only the acceleration portion of any experiment that is responsible for time dilation, always exists. ”

Again, fair enough. But I do think you're wrong about the lack of hard evidence. There have been long flights with atomic clocks, centrifuge experiments, there's GPS, and Nasa missions. With the understanding of relativity that abounds along with my own concepts, that's enough for me to assert that you've got the wrong idea.

All of the above involve acceleration. There can be no physical experiment that does not involve acceleration to some degree or another. You can assert all you like but I am in search of the truth as to why the arrow of time exists. It is a real fundamental question that has been passed off as ‘psychological’ without trying to find a reason for it. I can see the reason why Einstein viewed velocity as a cause of time dilation in the way he viewed spacetime but there is another way to look at spacetime which encompasses times arrow.

“If I never bothered to learn physics and had to keep looking up definitions of units then would not try and discuss physics with people who have. I don’t disagree with velocity causing time dilation if you view spacetime as a metric as Einstein did but there is an alternative and it is this alternative that I am exploring. I am new to this website so I cannot comment on Pastafarian’s level of knowledge but if I agree with him then I will say so.”

No problem. It's good to talk.

Yes it is. Without communication there is no way to advance knowledge.

“You are just putting your view of the mathematical axioms and everyone is entitled to a view but without following up this view with extra math to solidify your perspective of reality then how do you expect physicists to take notice? ”

I expect them to show some interest. I don't expect them to say there's no maths so that's not physics. That's like saying there's no French so that's not English. It's a false premise used for dismissal and clinging to current concepts. Physics shouldn't be like that. It should be open, rational, exploring. I also expect physicists to appreciate that a postulate (or an axiom) is very different to explanation. Einstein postulated that c is always measured to be the same value, I can explain why.

This is not about clinging to current concepts. If your essays make testable predictions that can be verified that are different from the mainstream view of physics then that will allow them to investigate your interpretation of reality. I cannot see any of your essays doing this as they stand at the moment. The language of physics is math and if you cannot use math to explain your essays to physicists then you might as well write your essays in a foreign language.

“I have read your essays and they do nothing for me so I would like to ask you, to what level have you studied physics? ”

I challenge that. I don't think you'd be asserting that acceleration causes time dilation if you'd read TIME EXPLAINED or GRAVITY EXPLAINED. But OK, if you've skimmed them briefly because they don't attract you, that's something I should look at. My formal physics education ended at A-level, and I've done private reading over twenty-something years. Yes, I'm an outsider, an amateur. I have a Computer Science degree and work as an IT Manager. Perhaps the most useful aspect of my skillset has been the Systems Analysis.

Why would you think your essays would change my mind that acceleration causes time dilation? They are just your interpretation of reality.
I know you are an amateur and therefore if you have a point to try and make to mainstream physics then do so in the language they understand in the form of math along side your essays. You might find it helps to solidify your own understanding of your ideas.

Tony

 

[Janus58]

Janus58



But the equivalence principle states that all accelerated reference frames possess a gravitational field then this must mean the more acceleration the deeper in the gravitational field for the equivalence principle to hold true.

There is not always a direct relationship between acceleration and depth of gravitational field. You can have a strong local acceleration in with a shallow feild and a weaker local acceleration in a deep field. Case in point: The surface gravity of Uranus is less than that of the Earth's, yet the surface of Uranus is deeper in its respective gravitational field than the surface of the Earth is in its field.

Gravity itself is not a force it is a distortion of spacetime so according to the EP any object under acceleration will posses a distortion of spacetime and the greater the acceleration the greater the distortion. Any kind of g-load will create gravitational time dilation.

Using the dimple in the rubber sheet analogy. The slope of the at any given point of the dimple is the local g-load. The distance below the normal "flat" level of the sheet is the depth in the field. It is perfectly possible to have two "dimples" where at a in one the slope at a given point is less than the slope at the point of the other, but is still deeper in its gravity well.
It is this depth in the field that determines gravitational time dilation.

Again, using Uranus as an example. The formula for gravitational time dilation for a body such as a planet is:
to =tf(sqrt(1- 2GM/(rc²)))

Where to is the time dilated time period.
tf is the time period as measured by an observer removed from the field
G is the gravitational constant
M the mass of the planet
r the distance from the center of the planet.

At the surface of the Earth, this works out to

to = tf(0.999999999)

Meaning that said removed observer sees 0.999999999 secs pass on the surface of the Earth fro every second he measures.

For Uranus, this works out to

to = tf(.999999997)

Meaning that the time dilation is greater at the Surface of Uranus than it at the Surface of the Earth, yet the surface gravity of Uranus is less (.889g) than that of the Earth. If gravitational time dilation was due to local strength of field, (magnitude of acceleration) you would get the opposite results.

If your contention is that the accepted formula for time dialtion is wrong, and one that the controlling factor is local g-load, then why is it that every experiment done to test gravitational time dilation (such as the HArvard Tower Experiment) give results that agree with this formula?

The equivalence principle has nothing to do with velocity other than angular velocity which is everything to do with acceleration and I’m still waiting for you to point me in the direction of these experiments so I can confirm your view of the EP.

Tony

The point is that the time dilation measured by the outside observer will rely on the radial velocity alone, and the observer on the centrifuge will agree with him as to the degree of that time dilation in all cases, even though the g-load he locally measures can vary depending on the different combinations of angular velocity and his distance from the center that result in the same radial velocity.


Here's a link to an article in Nature describing such an experiment.

Bailey, J. et al., Nature 268, 301 (1977) on muon lifetimes and time dilation.

Muons orbit in a circular storage ring and their time dilation measured. The results match those predicted by the standard Lorentz transformation which only takes the radial velocity into account.

 

[Janus58]

James R



But there is an element of acceleration involved here. Muon decay is caused be high energy cosmic rays impacting air molecules producing pions which decay into muons. The point here is they have been accelerated by the impact and experience deceleration through the atmosphere so not only velocity is involved.

Tony

It's not enough to just say that there is an element of acceleration involved. To support the claim that it is the acceleration that is the culprit in time dilation, you have to show how the particular accelerations result in the time differences involved and still match those predicted by the standard "velocity only" formula. IOW, where's the math?

And not only for this experiment, but every experiment done in every high energy particle lab in the world, which use different designs, with different acceleration magnitudes and durations, yet still produce results that are always in agreement with velocity alone being the factor in time dilation.

 

[Farsight]

That's interesting Janus, thanks.

Do you really understand time? If so can you explain time’s arrow, why time has a direction, why we have a past and why the future is not set in stone? Do you think it is a psychological process as Einstein did or do you think time’s arrow should have a real explanation in physics?

Yes I do Uclock. And you haven't read TIME EXPLAINED at all, because if you had you would have seen how scathing I was about the Arrow of Time. It's merely a counting direction. I called it the Arrow of Beans. Time is a derived effect of motion. Like heat. And like heat it is not imaginary, but it is not fundamental. Did you notice the 1949 in my post? When did Einstein write Special Relativity part III? Aw that's enough, you've made up your mind that acceleration causes time dilation, you ignore anything that demonstrates that this is incorrect, you pretend you've read background material but get caught out and make up fatuous reasons as to why you don't need to bother. So just forget it.

 

[kwhilborn]

Is there an argument that Acceleration does not cause time dilation here?

It is a controversial subject that NASA is planning to prove or disprove once and for all. What is wrong with the atomic clock on the plane experiments again?

I accept that velocity and gravity affect perspective times based mostly on those. The longevity of particles or "muons" based on their comparative life expectancy has been attacked a lot, but I am only a reader of these experiments. Helionic waves or whatever.

The GPS answer I thought was the best for non velocity time dilation, however it is true that velocity may be a factor in that.

The two experiments that I feel have proved both Velocity and gravity time dilation are these.

a) the atomic clock in plane experiment.

b) the atomic clocks at high altitudes (no velocity) experiments. This is where clocks have been left atop mountains and eventually are eventually off. The most accurate clocks are atomic clocks, but due to the gravitational redshift, the oscillations of atoms will vary with gravity- that is, their frequency will change depending on the value of the gravitational field they are in. The gravity will affect the frequency of the atoms. Therefore, time runs faster at higher altitudes. Due to the same effect that makes time run faster at higher altitudes, it would run more slowly in a large gravitational field.

c) my empoyees seem to work slower when I am in a rush. (this has just been a personal observation and not scientific. lol)

So Einsteins math has withstood some pretty heavy measuring. How can we argue with a theory that makes sense, and stands up to measurements?

So yes; There has been non-velocity time dilation experiments involving high altitudes and atomic clocks.

 

[Janus58]

b) the atomic clocks at high altitudes (no velocity) experiments. This is where clocks have been left atop mountains and eventually are eventually off. The most accurate clocks are atomic clocks, but due to the gravitational redshift, the oscillations of atoms will vary with gravity- that is, their frequency will change depending on the value of the gravitational field they are in. The gravity will affect the frequency of the atoms. Therefore, time runs faster at higher altitudes. Due to the same effect that makes time run faster at higher altitudes, it would run more slowly in a large gravitational field.

Again, it is not the local value of the gravity field that results in gravitational time dilation, but the difference in gravtational potential, or relative depth in the field. This is what Einstein's math predicts and the experimental results show. IOW, Einstein predicts that if you had a uniform gravitational field (One where g does not vary with height), two clocks, placed at different heights in that field, will still run at different rates, even though both clocks experience the same g force.

 

[Uclock]

Janus58

There is not always a direct relationship between acceleration and depth of gravitational field. You can have a strong local acceleration in with a shallow feild and a weaker local acceleration in a deep field. Case in point: The surface gravity of Uranus is less than that of the Earth's, yet the surface of Uranus is deeper in its respective gravitational field than the surface of the Earth is in its field.

Only because of greater mass of Uranus increasing its schwartzchild radius but it is a gas giant and therefore as such it has no surface. Unfortunately we can’t actually physically test this hypothesis.

Using the dimple in the rubber sheet analogy. The slope of the at any given point of the dimple is the local g-load. The distance below the normal "flat" level of the sheet is the depth in the field. It is perfectly possible to have two "dimples" where at a in one the slope at a given point is less than the slope at the point of the other, but is still deeper in its gravity well.
It is this depth in the field that determines gravitational time dilation.

Again, using Uranus as an example. The formula for gravitational time dilation for a body such as a planet is:
to =tf(sqrt(1- 2GM/(rc²)))

Where to is the time dilated time period.
tf is the time period as measured by an observer removed from the field
G is the gravitational constant
M the mass of the planet
r the distance from the center of the planet.

At the surface of the Earth, this works out to

to = tf(0.999999999)

Meaning that said removed observer sees 0.999999999 secs pass on the surface of the Earth fro every second he measures.

I am sorry Janus58 but I think you may have that the wrong way around. The person on the surface of the Earth will see the observers clock outside the gravitational field beat once every 0.99999999s for every one beat of his own clock, otherwise it would mean that clocks beat faster inside a gravitational field than outside which is not the case.

For Uranus, this works out to

to = tf(.999999997)

Meaning that the time dilation is greater at the Surface of Uranus than it at the Surface of the Earth, yet the surface gravity of Uranus is less (.889g) than that of the Earth. If gravitational time dilation was due to local strength of field, (magnitude of acceleration) you would get the opposite results.

If your contention is that the accepted formula for time dialtion is wrong, and one that the controlling factor is local g-load, then why is it that every experiment done to test gravitational time dilation (such as the HArvard Tower Experiment) give results that agree with this formula?

I take it you mean the Pound-Rebka experiment performed at Harvard University.
Yes it is apparently accurate to within 1% of Einstein’s value which is pretty good isn’t it? I do not have access to the actual paper but I think I may be able to do better than Einstein at calculating time dilation by viewing spacetime differently.

The point is that the time dilation measured by the outside observer will rely on the radial velocity alone, and the observer on the centrifuge will agree with him as to the degree of that time dilation in all cases, even though the g-load he locally measures can vary depending on the different combinations of angular velocity and his distance from the center that result in the same radial velocity.

Yes, according to Einstein you are correct but I think his view of spacetime is wrong, he may be close but he is never quite spot on is he?

Here's a link to an article in Nature describing such an experiment.

Bailey, J. et al., Nature 268, 301 (1977) on muon lifetimes and time dilation.

Muons orbit in a circular storage ring and their time dilation measured. The results match those predicted by the standard Lorentz transformation which only takes the radial velocity into account.

Again, the Loretz transformation is close but we are also talking about centripetal acceleration involved here not just velocity. It may we be the rate of acceleration that is causing the effect and not the velocity.

Tony

 

[Uclock]

post #35

Janus58

It's not enough to just say that there is an element of acceleration involved. To support the claim that it is the acceleration that is the culprit in time dilation, you have to show how the particular accelerations result in the time differences involved and still match those predicted by the standard "velocity only" formula. IOW, where's the math?

And not only for this experiment, but every experiment done in every high energy particle lab in the world, which use different designs, with different acceleration magnitudes and durations, yet still produce results that are always in agreement with velocity alone being the factor in time dilation.

I agree. I do not intend to just say that there is another way to view and calculate time dilation unless I have the math to back it up.
There is another way to view space and time which for the first time accounts for the arrow of time as a physical phenomenon. This view of spacetime is radical but testable but any University or institution with the correct facilities. I will be posting this concept of spacetime shortly, including a paper on time dilation.
My earlier posts are a little misleading because it is not acceleration per se that causes time dilation. It is forced displacement in spacetime such as when an object is acted on by an unbalanced force.

Tony