TIME DILATION. WHY do clocks that are

[PAllen]

Read again two posts back.
It appears that simultaneity is "opaque" when the events are aligned with the observer.
Comment on my explanation and I'll know how to clear it for you.

This has no meaning for anyone who has studied physics. To try to get at what you might mean, consider the following:

I have a 1 meter stick. In the middle I have red light that flashes every second. At the far end I have blue light that flashes every second. I am at the 'near' end. All synchronization of clocks done by slow transport. I see blue flashes arrive a tiny bit later than red flashes. Accounting for light speed, I conclude the emission events were simultaneous. Where is the opaqueness of simultaneity?

[Dalespam is not being rude for reminding you of forum rules. These forums are intended to discuss physics, specifically defined as peer reviewed theories in established journals. There are other places on the web to discuss theology, 'alternative science', or whatever. But when you register here you agree to discuss mainstream science. ]

 

[ghwellsjr]

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 let's 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.

OK, we'll make sure the moving ship has inertial dampeners so that no change in direction will be felt by the traveling twin.

You and sisoev are so close to understanding this, I think the best way to help you is to use an analogy to sound Doppler. We're all familiar with the shift in the pitch of an emergency vehicle's siren as it passes by us going from a higher rate to a lower rate. To make things easier, let's assume that the siren is putting out a single frequency sound instead of the typical siren that is modulated all over the place, and let's assume that it is very loud so we can hear it from a great distance away. Once that vehicle has passed us and we are hearing the lower rate sound, it will stay at that same low rate as long as the vehicle maintains a constant speed. But let's suppose that after it has gone a mile from us, the vehicle shuts off its emergency lights and its siren at the same time. What will we see and hear? Well, even kids know that it takes about five seconds for the sound to travel a mile so it will take five seconds for us to hear the sound drop out after the lights turn off, correct? But now let's suppose that instead of turning off the siren, the vehicle turns around very quickly, in a fraction of a second, what will we see and hear? Well, again, about five seconds after we see it turn around, we will hear the pitch change from its lower rate to the higher rate, correct? And it will stay at the higher rate until it reaches us, I'm sure you will agree.

Now let's consider a slightly different situation where the emergency vehicle is stopped with its siren blaring out a loud constant frequency. Then suppose we are in a vehicle approaching it. No matter how far away we are, we will hear the higher rate sound, and just like before, as we pass it the sound will drop from the higher rate to the lower rate, correct? But then suppose a mile down the road, we make a quick turn around. What will we hear? If you give it a little thought, I think you will conclude that we immediately hear the pitch go from the lower rate to the higher rate, don't you agree? If you don't agree, then when will we hear the switch from the lower rate to the higher rate, because remember, when we get to the siren and pass it, the pitch has to pass from the higher rate to the lower rate.

So what have we learned? When we are colocated with the source of the sound, we immediately hear the change in the rate of the sound's pitch but when we are located a distance from the source of the sound, we will hear the pitch change immediately if we're the one changing speed but we will hear it sometime later if the source of the sound is changing speed.

Now, is there anything in this analogy that you don't understand or don't agree with?

 

[sisoev]

This has no meaning for anyone who has studied physics. To try to get at what you might mean, consider the following:

I have a 1 meter stick. In the middle I have red light that flashes every second. At the far end I have blue light that flashes every second. I am at the 'near' end. All synchronization of clocks done by slow transport. I see blue flashes arrive a tiny bit later than red flashes. Accounting for light speed, I conclude the emission events were simultaneous. Where is the opaqueness of simultaneity?

[Dalespam is not being rude for reminding you of forum rules. These forums are intended to discuss physics, specifically defined as peer reviewed theories in established journals. There are other places on the web to discuss theology, 'alternative science', or whatever. But when you register here you agree to discuss mainstream science. ]

Imagine that you observe red light and blue light behind it. I don't know what mixture of color will be your observation, but when the lights simultaneously stop, you'll not see blue light coming to you.

I know the rules.
What I did not expected was to be forced to agree or to leave the forums.
Further more, the moderator can decide to close the topic if he/she decides that it becomes meaningless.
I am learning in discussion.
You guys have the chance to answer my arguments and convince me otherwise.
That will be the best way to educate me :)

 

[Denius1704]

Now, is there anything in this analogy that you don't understand or don't agree with?

Thank you ghwellsjr, i do understand the analogy and i do see the whole problem a bit clearer now, it helped.

Basically that would also mean that in a system of only two bodies, one moving and one stationary, even without the effect of an acceleration being felt we would still be able to say which one is moving and which one isn't, because of this effect? Am i right in assuming this?

Thanks again for the lengthily explanation.

 

[Dale]

That is not good attitude, DaleSpam :)
I showed gratitude and respect to you.

It has nothing to do with gratitude and respect. It has to do with the rules of the forum, which you agreed to when you signed up for your account. Please click on the link labeled "Rules" at the top of the page and re-read the section on Overly Speculative Posts.

We welcome students who have a question and come hear to learn, we do not welcome crackpots who have an agenda and come here to argue. You have shown signs of the latter (claims that contradict experimental observations) and you have not shown signs of the former (willingness to learn when information is provided).

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.

But you are ignorant of relativity. You do not even know the definition of very basic terms in relativity like "event". What is worse, you are deliberately ignorant and unwilling to learn, even when the information is spoon-fed to you. Ignorance is fine and easily overcome, but unwillingness to learn is not.

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 ;)

If we were discussing those fields then that would be relevant and I would seek to learn from you and I would read the links you provided in order to better educate myself and overcome my ignorance in those fields. But we are not discussing those fields, we are discussing relativity.

 

[Dale]

the light will be directed down when the back door is opened ... Because we cannot have two 90 degree positioned light beams from one light source

Do you mean that the lights on the door are lasers or other tightly-collimated sources that only point in one direction rather than spherical waves that point in all directions? If so, then just use standard light bulbs that radiate spherically.

You seem to be trying to come up with specific tiny details that avoid the essence of the physics. The usual formulation of the ladder paradox never even mentions any lights. The existence and position of any light bulbs and the material of the door are irrelevant to whether or not the door is open or closed at a given time. Turning on or off the lights will not prevent you from crashing into a closed door nor will it make you crash into an open door.

IMO, the lights are just a red herring, but if you insist on having them for some reason then simply make them spherical-wave sources and make the doors transparent.

 

[PAllen]

Imagine that you observe red light and blue light behind it. I don't know what mixture of color will be your observation, but when the lights simultaneously stop, you'll not see blue light coming to you.

That is absurd. You will see a moment of pure red light, then a mixture of red and blue, then pure blue light. Even though each flash's start and stop are simultaneous, one emitter is further away.

If you deny this, there is no point of discussion - forget relativity, you are denying observable reality.

 

[ghwellsjr]

Thank you ghwellsjr, i do understand the analogy and i do see the whole problem a bit clearer now, it helped.

Basically that would also mean that in a system of only two bodies, one moving and one stationary, even without the effect of an acceleration being felt we would still be able to say which one is moving and which one isn't, because of this effect? Am i right in assuming this?

Thanks again for the lengthily explanation.

No, it's not a matter of which one is moving, it's a matter of which one is changing speed or direction and where the two are in relation to each other when this happens.

So let's extend the analogy a little bit to include your question:

Suppose you are stopped and the vehicle with the siren passes you and you hear the sound drop in pitch from the high rate to the low rate and after it is a mile down the road, you take off after it at the same speed it is going. Now you will hear the pitch go from the low rate to the actual pitch of the siren, won't you? So there you both are separated by a mile, both moving and it's just like you were both stationary in terms of what you are hearing. But now if you increase your speed, you will immediately hear the pitch go higher, right? But instead of that, suppose the other vehicle slows down, will you immediately hear the pitch get higher? No, not until five seconds goes by.

Once you grasp the idea that distance causes a delay in what you observe if the other person changes speed but no delay if you are the one that changes speed, then you can easily understand the Twin Paradox with no math, no equations, no formulas.

Does this make perfect sense to you now?

 

[sisoev]

That is absurd. You will see a moment of pure red light, then a mixture of red and blue, then pure blue light. Even though each flash's start and stop are simultaneous, one emitter is further away.

If you deny this, there is no point of discussion - forget relativity, you are denying observable reality.

You are building your experiment on wrong analogy, PAllen.

Imagine that sometime in the past a red light (in the front) and blue light (behind the red) were mixed for you.
Now we deal with two different information (red and blue) mixed into one information (let say purple)
Now imagine that both information(colors) are simultaneously extracted.
What will be left?
Non.

Taking this to a transparent doors (red and blue) you'll see a purple door which opens.
Behind it we will see what ever is behind the blue door

 

[Denius1704]

No, it's not a matter of which one is moving, it's a matter of which one is changing speed or direction and where the two are in relation to each other when this happens.

So let's extend the analogy a little bit to include your question:

Suppose you are stopped and the vehicle with the siren passes you and you hear the sound drop in pitch from the high rate to the low rate and after it is a mile down the road, you take off after it at the same speed it is going. Now you will hear the pitch go from the low rate to the actual pitch of the siren, won't you? So there you both are separated by a mile, both moving and it's just like you were both stationary in terms of what you are hearing. But now if you increase your speed, you will immediately hear the pitch go higher, right? But instead of that, suppose the other vehicle slows down, will you immediately hear the pitch get higher? No, not until five seconds goes by.

Once you grasp the idea that distance causes a delay in what you observe if the other person changes speed but no delay if you are the one that changes speed, then you can easily understand the Twin Paradox with no math, no equations, no formulas.

Does this make perfect sense to you now?

Thanks for extending the explanation, but those are just variations of the same principle. My last question about two objects in a system was just to satisfy a philosophical question and you did answer it (albeit i didn't formulate the question as properly as it was in my head :) ). In the extended example you give, if those two cars are isolated in a system with just themselves, when they are both moving with the same speed that would be equal to being stationary, so when the one "slows" down as it is in your example that would translate that it is actually accelerating towards the other "stationary" car. Doesn't mattet, i get the example :)

 

[sisoev]

OK PAllen, I know where is the deceiving point in your thinking (no offence applied)

When you think SIMULTANEITY in your experiment, think that when the back(blue) light cease to exits the front(red) line die simultaneously with it

 

[ghwellsjr]

Thanks for extending the explanation, but those are just variations of the same principle. My last question about two objects in a system was just to satisfy a philosophical question and you did answer it (albeit i didn't formulate the question as properly as it was in my head :) ). In the extended example you give, if those two cars are isolated in a system with just themselves, when they are both moving with the same speed that would be equal to being stationary, so when the one "slows" down as it is in your example that would translate that it is actually accelerating towards the other "stationary" car. Doesn't mattet, i get the example :)

Great, now do you think you could explain the Twin Paradox to someone who doesn't understand it?

 

[PAllen]

You are building your experiment on wrong analogy, PAllen.

Imagine that sometime in the past a red light (in the front) and blue light (behind the red) were mixed for you.
Now we deal with two different information (red and blue) mixed into one information (let say purple)
Now imagine that both information(colors) are simultaneously extracted.
What will be left?
Non.

Taking this to a transparent doors (red and blue) you'll see a purple door which opens.
Behind it we will see what ever is behind the blue door

You write gibberish and deny reality. Truly no further discussion is possible.

 

[sisoev]

You write gibberish and deny reality. Truly no further discussion is possible.

Just in case you missed my previous post;
When you think SIMULTANEITY in your experiment, think that when the back(blue) light cease to exits the front(red) line die simultaneously with it.

Now it should make sense to you :)

 

[PAllen]

Just in case you missed my previous post;
When you think SIMULTANEITY in your experiment, think that when the back(blue) light cease to exits the front(red) line die simultaneously with it.

Now it should make sense to you :)

No this is total nonsense. Suppose each pulse is one femtosecond. Then there is no overlap at all between two simultaneously emitted pulses, one right behind the other. They will be received separately, and the receiver (having set up the experiment and measured everything) can easily determine that the delay between them verifies simultaneous emission.

Try to write clear English. That is a real problem - much of what you write is incomprehensible as English.

 

[Sandrix]

Can i say something here for first time :P
Time is derivative of mass :P
If mass dosent exist or = zero than there is no dimension Time :)
time not exist if M=0 or we have pure energy :)
have fun :)

 

[sisoev]

No this is total nonsense. Suppose each pulse in one femtosecond. Then there is no overlap at all between two simultaneously emitted pulses, one right behind the other. They will be received separately, and the receiver (having set up the experiment and measured everything) can easily determine that the delay between them verifies simultaneous emission.

Try to write clear English. That is a real problem - much of what you write is incomprehensible as English.

The femtosecond does not make you see red door and blue door behind it. You see purple door.
Your example with the pulses is not identical with the door experiment.
Remember that the front door is blocking the information for the back one, and if they are transparent, the colors are mix into one.
Your example does not set the front pulse as blockage for the back one.
There is time when we see only the front door.
Where in your experiment is the time when we see only the front pulse.

 

[PAllen]

The femtosecond does not make you see red door and blue door behind it. You see purple door.
Your example with the pulses is not identical with the door experiment.
Remember that the front door is blocking the information for the back one, and if they are transparent, the colors are mix into one.
Your example does not set the front pulse as blockage for the back one.
There is time when we see only the front door.
Where in your experiment is the time when we see only the front pulse.

A front transparent door doesn't cause mixing. If a signal from front and back door emitted simultaneously, they will arrive one after the other. If they arrive at the same time, that tells you they were not emitted simultaneously, and further (assuming you set up the experiment) it tells exactly what the difference in emission time is.

Repeating trivially false statements does not make them true.

 

[Dale]

The femtosecond does not make you see red door and blue door behind it. You see purple door.
Your example with the pulses is not identical with the door experiment.
Remember that the front door is blocking the information for the back one, and if they are transparent, the colors are mix into one.
Your example does not set the front pulse as blockage for the back one.
There is time when we see only the front door.
Where in your experiment is the time when we see only the front pulse.

None of which is in any way relevant for the ladder paradox.

 

[Dale]

When you think SIMULTANEITY in your experiment, think that when the back(blue) light cease to exits the front(red) line die simultaneously with it

It is hard to tell what you mean, but when a light source stops emitting light the light that it has already emitted does not suddenly cease to exist but instead continues to propagate onward at c. Otherwise you would violate the conservation of energy. So, if two sources stop emitting light simultaneously in some frame then an observer does not necessarily stop receiving the light simultaneously.

Would you like a mathematical derivation to back that up?

 

[Denius1704]

Great, now do you think you could explain the Twin Paradox to someone who doesn't understand it?

Yeahp i believe i can, because after your example the way i had to translate it to myself so i can picture it better was with a sonar given out between two whales... Then the picture became quite clear :)

 

[sisoev]

A front transparent door doesn't cause mixing. If a signal from front and back door emitted simultaneously, they will arrive one after the other. If they arrive at the same time, that tells you they were not emitted simultaneously, and further (assuming you set up the experiment) it tells exactly what the difference in emission time is.

Repeating trivially false statements does not make them true.

First of all in the garage door experiment we are dealing with the reflected light of the front door, which blocks us from seeing the back door.
We made them transparent for the sake of the argument.
We can make them transparent and emitting light, but that will not change anything.
If the back door is blue, we will have to see it through the front red transparent door, and we will see purple.
(I don't know how do you imagine a blue light to arrive unchanged trough red door.)
Now stop the back blue emission and the front red one at the same time.
What do you see?

Stop thinking about your opponent as an idiot and you may start seeing his point.

 

[PAllen]

First of all in the garage door experiment we are dealing with the reflected light of the front door, which blocks us from seeing the back door.
We made them transparent for the sake of the argument.
We can make them transparent and emitting light, but that will not change anything.
If the back door is blue, we will have to see it through the front red transparent door, and we will see purple.
(I don't know how do you imagine a blue light to arrive unchanged trough red door.)
Now stop the back blue emission and the front red one at the same time.
What do you see?

Stop thinking about your opponent as an idiot and you may start seeing his point.

Who says the front door is red? Transparent and clear, with flashing red light source would make sense. Backdoor would have synchronized flashing blue source.

Anyway, what I was responding to was your claim that you can't determine collinear simultaneity as a general principle.

 

[Dale]

First of all in the garage door experiment we are dealing with the reflected light of the front door, which blocks us from seeing the back door.
We made them transparent for the sake of the argument.
We can make them transparent and emitting light, but that will not change anything.
If the back door is blue, we will have to see it through the front red transparent door, and we will see purple.
(I don't know how do you imagine a blue light to arrive unchanged trough red door.)
Now stop the back blue emission and the front red one at the same time.
What do you see?

Why does what you see matter? If the door is closed when the ladder is in the doorway then it crashes regardless of what is seen. If the door is open when the ladder is in the doorway then it passes regardless of what is seen.

It is a red herring, not a red door.

 

[sisoev]

I'm taking a little brake to clear my mind :)

 

[sisoev]

OK.
Let's see it differently in order for me to understand you and you to get my point.
It will be easy for us to imagine the doors as transparent red (front) and blue(back) doors.
The light reflected from the front door will show it to us as red, but it will go trough it, reflect in the back door and will bring to us information for purple back door.
Am I correct?

When the doors open simultaneously, we will see purple door which is not open, but since we know that the actual door is blue, that will tell us that the door is open and we see false image of it.
The explanation of the ladder experiment still fails for me :)

Please tell me where am I wrong.

 

[Dale]

When the doors open simultaneously, we will see purple door which is not open, but since we know that the actual door is blue, that will tell us that the door is open and we see false image of it.
The explanation of the ladder experiment still fails for me :)

Please tell me where am I wrong.

You are wrong in thinking that the color of the door has any relevance whatsoever to whether or not the ladder hits the door. If the color mattered then we could just paint all cars some collision-proof color and greatly enhance road safety.

 

[sisoev]

You are wrong in thinking that the color of the door has any relevance whatsoever to whether or not the ladder hits the door.

You are right, but in the proposed experiment, the color which we see proves that the door is actually not there.
Aren't the experiments set to prove or disprove something?

 

[Dale]

You are right, but in the proposed experiment, the color which we see proves that the door is actually not there.

No it doesn't. Let me see if I understand your set-up for complete clarity. You are proposing a red transparent front door and a blue opaque back door with ambient white lighting from outside and no light sources either on the door or in the garage, correct?

 

[sisoev]

No it doesn't.

Ha-ha :D
OK...
I'm done with this topic.
I'll come back with the experiment I mentioned earlier.

Love to all you guys :)