# TIME DILATION. WHY do clocks that are

by abbott287
Tags: clocks, dilation, time
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P: 17,333
 Quote by sisoev My point is that we cannot treat an overlapping simultaneous events like a simultaneity since the light from them brings information only for one of them.
What do you even mean by the phrase "overlapping simultaneous events"?
P: 117
 Quote by DaleSpam What do you even mean by the phrase "overlapping simultaneous events"?
Aligned with the observer.
 Mentor P: 17,333 How is an event aligned with anything, let alone an observer? When I use the word "aligned" I mean that two things which have some associated direction or axis are parallel. Events do not have a direction or an axis. Do you mean something like the event is on the observer's worldline?
P: 117
 Quote by DaleSpam How is an event aligned with anything, let alone an observer?
Well, an event is actually light information for an observer.
Now, align the light information for the two simultaneous events with the observer and you'll have the information only for the front event.
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P: 17,333
 Quote by sisoev Well, an event is actually light information for an observer.
No, an event is a given place at a given time. I.e. the airplanes crashed at an altitude of 2 miles, at lattitude 45º, longitude 30º, at 3:00 pm. That is an event. The light emanating from that event forms a light cone with the origin at the event. The event is a 0-dimensional set, the light cone is a 3-dimensional set.

 Quote by sisoev Now, align the light information for the two simultaneous events with the observer and you'll have the information only for the front event.
Are you simply saying something to the effect that opaque objects (like garage doors) absorb light so you lose information about things on the other side of the object? If so, then simply make the doors out of glass.
P: 117
 Quote by DaleSpam This is factually incorrect. An accelerometer carried by one brother detects the g-forces of the turnaround, and an accelerometer carried by the other does not. The frequency of the pulses from the other brother changes immediately for one brother (the same one that detects the g-forces) and not for the other. The experiences of the two brothers are not the same.
The g-force doesn't only change the frequency of the emitted signals, but also the frequency of the perceived ones.
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P: 17,333
 Quote by sisoev The g-force doesn't only change the frequency of the emitted signals, but also the frequency of the perceived ones.
Do you agree that only one of the twins measures g-forces?
 P: 25 I think he is trying to say that how can we see any light reflected from the back door (so as to give the perception of it opening later than the front door) if that said back door opened at exactly the same time as the front one. Where would the information of that back door opening be carried and how would we perceive it? That is if i'm understanding his argument correctly.
P: 117
 Quote by DaleSpam No, an event is a given place at a given time. I.e. the airplanes crashed at an altitude of 2 miles, at lattitude 45º, longitude 30º, at 3:00 pm. That is an event. The light emanating from that event forms a light cone with the origin at the event. The event is a 0-dimensional set, the light cone is a 3-dimensional set.
No, an event is a light information.
No light information - no observation of an event.
If we don't observe an event we cannot measure its values.
You can set a values for non-observed event, like in the explanation of the ladder paradox but that holds the risk to create new paradox, and I think that SR has already enough of them ;)

 Quote by DaleSpam Are you simply saying something to the effect that opaque objects (like garage doors) absorb light so you lose information about things on the other side of the object? If so, then simply make the doors out of glass.
What I am saying is that if you turn two book pages at once you'll see the first and the third.
Hope that this is easy enough to picture it out :)
P: 117
 Quote by DaleSpam Do you agree that only one of the twins measures g-forces?
Yes, how couldn't I :)
P: 25
 Quote by DaleSpam This is factually incorrect. An accelerometer carried by one brother detects the g-forces of the turnaround, and an accelerometer carried by the other does not. The frequency of the pulses from the other brother changes immediately for one brother (the same one that detects the g-forces) and not for the other. The experiences of the two brothers are not the same.
When i suggested the example i thought we all agreed that there is no turnaround event, so what g-forces are we talking about now?

Imagine the guy from Earth was watching the one moving away and then the next second moving towards him. Why would the light need more time to reach the Earth guy all of a sudden if it was reaching him just fine until the last moment of moving away? If we are imagining an uninterrupted flow of light from the moment of departure to the moment the moving brother switches directions, i imagine the image the Earth brother would receive would be a sudden shift from the 1/2 rate to the 2 rate. And the same thing would occur for the moving brother as well, like a "mirror" as sisoev suggested.

Now, apparently my imagination is very wrong and the logic i am using as well, otherwise SR would not exist today. What i am asking for is not answers such as "you are wrong" and "well that doesn't happen because it's been accounted for", but instead to be shown where my logic breaks, at which point? I am not asking for mathematical equations, because when a client comes to me to explain to him a problem with the software i don't start talking to him in 0's and 1's, but instead i try and talk his language, the one he understands. Otherwise we will be sitting on this thread for weeks everyone saying the same things not understanding the others.

And for the sake of eliminating any kind of G-Force lets imagine both brother in space in their own respective space ships, with the moving ship being equipped with inertial dampeners (or whatever they call them in the movies these days) so that if there is ANY kind of change in acceleration it will not be felt at all by either the ship or the person in the ship.
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P: 17,333
 Quote by sisoev No, an event is a light information. No light information - no observation of an event. If we don't observe an event we cannot measure its values. You can set a values for non-observed event, like in the explanation of the ladder paradox but that holds the risk to create new paradox, and I think that SR has already enough of them ;)
No, this is incorrect. An event is something which happens at a given place at a given instant of time:
http://en.wikipedia.org/wiki/Event_(relativity)
http://www.colvir.net/prof/richard.b...el-an/rela.htm
http://www.hep.uiuc.edu/home/g-golli...ativity_7.html

 Quote by sisoev What I am saying is that if you turn two book pages at once you'll see the first and the third. Hope that this is easy enough to picture it out :)
Sure, pages are opaque. No big deal, just make the garage doors partially transparent.
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P: 17,333
 Quote by sisoev Yes, how couldn't I :)
Since you agree that one twin measures the g forces and the other twin does not then it is clear that the twins experience the turnaround differently. So your earlier claim is not correct:
 Quote by sisoev The "turning around" event has no special meaning in the experiment, ghwellsjr It is "experienced" from the other brother the same way as the brother who executes the event.
The brother who executes the turn experiences g forces, the other does not. It is not experienced the same way.
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P: 17,333
 Quote by Denius1704 When i suggested the example i thought we all agreed that there is no turnaround event, so what g-forces are we talking about now?
Sorry, I thought we were talking about the standard twins paradox. If there is no turnaround/no g-forces then the twins never reunite so there is no way to unambiguously compare their ages.

 Quote by Denius1704 Imagine the guy from Earth was watching the one moving away and then the next second moving towards him. Why would the light need more time to reach the Earth guy all of a sudden if it was reaching him just fine until the last moment of moving away? If we are imagining an uninterrupted flow of light from the moment of departure to the moment the moving brother switches directions, i imagine the image the Earth brother would receive would be a sudden shift from the 1/2 rate to the 2 rate. And the same thing would occur for the moving brother as well, like a "mirror" as sisoev suggested.
If there are no g-forces then there will be no shift in rate at all. The rate will be permanently 1/2.

 Quote by Denius1704 Now, apparently my imagination is very wrong and the logic i am using as well, otherwise SR would not exist today. What i am asking for is not answers such as "you are wrong" and "well that doesn't happen because it's been accounted for", but instead to be shown where my logic breaks, at which point? I am not asking for mathematical equations, because when a client comes to me to explain to him a problem with the software i don't start talking to him in 0's and 1's, but instead i try and talk his language, the one he understands. Otherwise we will be sitting on this thread for weeks everyone saying the same things not understanding the others.
I think we first need to clarify what scenario we are talking about. Do you want to have two perpetually inertial observers (no reunion, no unambiguous comparison of ages, no change in signal rate, perfectly symmetrical) or do you want to have one of the twins be non-inertial (g-forces, asymmetrical)? You cannot have it both ways.

 Quote by Denius1704 And for the sake of eliminating any kind of G-Force lets imagine both brother in space in their own respective space ships, with the moving ship being equipped with inertial dampeners (or whatever they call them in the movies these days) so that if there is ANY kind of change in acceleration it will not be felt at all by either the ship or the person in the ship.
That cannot be done in flat spacetime, and if you are struggling with the twins paradox then we definitely do not want to go to curved spacetime as that cannot be done effectively without some rather hairy math.
P: 117
 Quote by DaleSpam No, this is incorrect. An event is something which happens at a given place at a given instant of time: http://en.wikipedia.org/wiki/Event_(relativity) http://www.colvir.net/prof/richard.b...el-an/rela.htm http://www.hep.uiuc.edu/home/g-golli...ativity_7.html
The argument takes philosophical turn.
We couldn't talk about given place and given time if we didn't observe the event at given place and given time.
So "given place" and "given time" are properties of known event.
It becomes known through observation.
Observation becomes such through light information delivered to conscious mind or apparatus which will deliver the recorded information for the event to a conscious mind.

 Quote by DaleSpam Sure, pages are opaque. No big deal, just make the garage doors partially transparent.
That won't change anything, DaleSpam :)
It is not the front door that prevents you to see the delayed opening of the back door.
It is the simultaneity of the aligned with you events which does not leave information except for the front event (the one which is closed to you)

Earlier I tried to explain it with light attached to the inside of the back door.
The light turns on by a switch on the front door when it is completely open.
Since the events are simultaneous, the light will be directed down when the back door is opened.
If you insist that you'll see the front door open and the back door closed, then you'll have to see the light from the source attached on the back door (the front door is opened and switched it on).
Because we cannot have two 90 degree positioned light beams from one light source, we end up with new paradox, which does not help solving the ladder paradox.
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P: 17,333
You do not appear to be interested in learning physics. You seem to be a crackpot with an anti-relativity agenda. That is not permitted on this forum. If you become interested in learning relativity then I would be glad to help. If you just want an anti-relativity soapbox then I suggest sciforums instead.

The fact is that the term "event" has a clearly defined meaning in relativity and it is very distinct from the concept you are describing. The concept you are describing is called a "light cone" in relativity.

 Quote by sisoev It is not the front door that prevents you to see the delayed opening of the back door. It is the simultaneity of the aligned with you events which does not leave information except for the front event (the one which is closed to you)
How does simultaneity block the information? Simultaneity is not opaque. If the doors are transparent then the fact that they are closed doesn't stop any information.
P: 117
 Quote by DaleSpam You do not appear to be interested in learning physics. You seem to be a crackpot with an anti-relativity agenda. That is not permitted on this forum. If you become interested in learning relativity then I would be glad to help. If you just want an anti-relativity soapbox then I suggest sciforums instead.
That is not good attitude, DaleSpam :)
I showed gratitude and respect to you.
I can say that I'm not considering to read something only if I have enough knowledge about the subject.
You should not treat me as completely ignorant person.
I may know a little bit more than you in some fields of the science and philosophy.
Have that in mind and don't lose your nerves ;)
P: 117
 Quote by DaleSpam How does simultaneity block the information? Simultaneity is not opaque. If the doors are transparent then the fact that they are closed doesn't stop any information.