Relativity - Oh dear, here we go again!

[Paulhoff]

The perpetual motion machine that doesn’t work.

Paul

 

[ynot]

The perpetual motion machine that doesn’t work.

Paul

Whadaya mean “doesn’t work”!!??

Do you deny the evidence before you?

I offer further indisputable proof . . .

Now how am I going to spend that million bucks?

 

[schlitt]

Hey ynot, did you ever sort out your dilemma regarding this issue?

I had been pondering relativity lately, found this thread and started reading it with a completely compatible opinion of your first post.
Midway through the first page it suddenly struck me, and i think i understand the concept now.

The problem comes with viewing an event as happening with one true timeframe. When in reality, time does not work like this, time is created by the relative viewer, in relation the the event in space.

Once you abandon the idea that there is one true measure for a single event, you see how everyone's relative perspective is the only thing that matters, and this means their perspectives have to be adjusted for, if you are relying in information to be synchronized between each perspective.

(please anyone, correct me if i am wrong here)

 

[BillyJoe]

Midway through the first page it suddenly struck me, and i think i understand the concept now.

The problem comes with viewing an event as happening with one true timeframe. When in reality, time does not work like this, time is created by the relative viewer, in relation the the event in space.

Once you abandon the idea that there is one true measure for a single event, you see how everyone's relative perspective is the only thing that matters, and this means their perspectives have to be adjusted for, if you are relying in information to be synchronized between each perspective.

(please anyone, correct me if i am wrong here)

Yes, unfortunately, you are wrong.

What is really happening is what is happening from the point of view of someone at the point in space where it is actually happening. Everyone else sees something different happening, but that is only what seems to be happening from their point of view, not what is really happening. However, they can find out what is really happening by using the math derived from relativity theory to calculate what is happening at the point in space where it is actually happening.

I hope that makes sense....

....because it is a serious answer.

regards,
BillyJoe

 

[schlitt]

Yes, unfortunately, you are wrong.

What is really happening is what is happening from the point of view of someone at the point in space where it is actually happening. Everyone else sees something different happening, but that is only what seems to be happening from their point of view, not what is really happening. However, they can find out what is really happening by using the math derived from relativity theory to calculate what is happening at the point in space where it is actually happening.

I hope that makes sense....

....because it is a serious answer.

regards,
BillyJoe

OK, I understand what you are saying. But surely the person who is "at the point in space where it is actually happening" as you put it, is still merely seeing the event relative to themselves. The fact they are closer gives less dilation, but still some nevertheless? (unless everything were 100% static?)

Time comes from the measurement of movement through space, so those viewing a moving object at distance are not "wrong", in their measurements, they simply need to be adjusted for in relation to measurements taken at the source of the event measured (or anywhere else for that matter), due to the time measurement at that point being different. Given the parameters, this can be done mathematically.

Does that sound right?

 

[Tumbleweed]

Lets get back to the twins again. Once they are reunited back on earth, which one is going to tell the other that, despite appearances, there can be only one reality and they are both in fact the same age. Or are both realities existing simultaneously

 

[Ziggurat]

Lets get back to the twins again. Once they are reunited back on earth, which one is going to tell the other that, despite appearances, there can be only one reality and they are both in fact the same age. Or are both realities existing simultaneously

No. Only one reality exists. The traveling twin will be younger when they reunite, they will both agree on that. The difficulty many newcomers to relativity have with the problem is the fact that superficially it seems like it should be symmetric, but it isn't, and any complete analysis of the problem will reveal that asymmetry.

 

[Fredrik]

The problem comes with viewing an event as happening with one true timeframe. When in reality, time does not work like this, time is created by the relative viewer, in relation the the event in space.

Once you abandon the idea that there is one true measure for a single event, you see how everyone's relative perspective is the only thing that matters, and this means their perspectives have to be adjusted for, if you are relying in information to be synchronized between each perspective.

(please anyone, correct me if i am wrong here)

I don't know if you're wrong, but I also don't quite understand what you're saying. What I do know is that you need to consider at least two events to find any disagreement between different observers.

 

[Fredrik]

Lets get back to the twins again. Once they are reunited back on earth, which one is going to tell the other that, despite appearances, there can be only one reality and they are both in fact the same age. Or are both realities existing simultaneously

What Ziggurat said.

If you want to understand this problem, you will have understand the space-time diagram in post #239, so I suggest you start there.

 

[Paulhoff]

Lets get back to the twins again. Once they are reunited back on earth, which one is going to tell the other that, despite appearances, there can be only one reality and they are both in fact the same age. Or are both realities existing simultaneously

The one that traveled is younger.

Paul

 

[Tumbleweed]

Oh I fully agree that there is one final reality - that the twins are indeed of separate age, but they traveled different realities - or frames of reference- to get to the new frame of reference/reality. And I get that it got that way because distance was being traded, basically for time. V still equals d/t in each frame of reference
And I agree that the time dilation is one way and not symmetrical. In other words, the rocket is speeding away from the Earth and not also vice versa

 

[Tumbleweed]

Here's a puzzle that has always bugged me. You have two objects headed towards each other at the speed of light. They acheive this by each approaching a fixed point in a straight line in space at half the speed of light.
Taking the twins thingie and relativity's time/distance differential to the extreme, would not the distance between the two objects shrink to zero (for them only) no matter how many light years they are said to be apart as judged by a third observer? Or looking at it another way, would the elapsed time clock on each space ship read zero (as well as the odometer) when they met, again regardless of how many light years they appear to be apart by an independent observer. Or even regardless as to ANY outside observation, not within their frame of reference

 

[sol invictus]

Here's a puzzle that has always bugged me. You have two objects headed towards each other at the speed of light. They acheive this by each approaching a fixed point in a straight line in space at half the speed of light.
Taking the twins thingie and relativity's time/distance differential to the extreme, would not the distance between the two objects shrink to zero (for them only) no matter how many light years they are said to be apart as judged by a third observer?

No.

Velocities don't add like that in relativity. Each object will see the other moving towards it at 4/5 the speed of light.

http://en.wikipedia.org/wiki/Velocity-addition_formula

 

[schlitt]

I don't know if you're wrong, but I also don't quite understand what you're saying. What I do know is that you need to consider at least two events to find any disagreement between different observers.

Yes, i agree.

The discrepancy between the two events is real, due to time being linked with the observer. The concept that there is no absolute time is what i think throws a lot of people.

 

[Tumbleweed]

No.

Velocities don't add like that in relativity. Each object will see the other moving towards it at 4/5 the speed of light.

http://en.wikipedia.org/wiki/Velocity-addition_formula

Okay assuming its only .8 the speed of light. It would still take far less time for them to meet as far as their clocks are concerned, as compared to an outside observors calculations using Newtonian physics would have calculated, right? The inference being that the vast distances to the galaxies might be not be that, the distance depending on relative velocity instead of Newtonian calculations

 

[Tumbleweed]

Here'a another puzzle. You have the Earth and a fixed point way out in space. You took a tape measure and measured the exact distance to that fixed point. THe point is moving in harmony with the earth through the cosmos, so the distance is always the same
Various and sundry objects pass throught that fixed point all at different speeds and angles. As they pass through that point, they each measure the exact distance to Earth, Do ANY of their calculations agree with either your measurement or anyone elses. Or will they all be different

 

[Paulhoff]

Here'a another puzzle. You have the Earth and a fixed point way out in space. You took a tape measure and measured the exact distance to that fixed point. THe point is moving in harmony with the earth through the cosmos, so the distance is always the same
Various and sundry objects pass throught that fixed point all at different speeds and angles. As they pass through that point, they each measure the exact distance to Earth, Do ANY of their calculations agree with either your measurement or anyone elses. Or will they all be different

If I am not mistaken, the only ones that will be the same, are those that travel at right angles to the earth thru that point.

>>>>>>>>>.>>>>>>>>>> the period is the fixed point



__________"E"arth


Paul

 

[Fredrik]

Oh I fully agree that there is one final reality - that the twins are indeed of separate age, but they traveled different realities - or frames of reference- to get to the new frame of reference/reality.

Please don't use the word reality here. It looks horrible. Even if we remove that word, that sentence still looks strange. The traveling twin changed his frame of reference by changing his velocity, not by changing his position.

And I agree that the time dilation is one way and not symmetrical. In other words, the rocket is speeding away from the Earth and not also vice versa

No, time dilation is symmetrical here. If both of the twins say "my brother's aging slower than me", they're both right. The reason why this symmetry doesn't cause a paradox is that something else entirely happens when the rocket turns around. It's not a physical effect. It's just a change of coordinates. I explained these things earlier in the thread (starting with post #239, near the end of page 6).

(And it's just as correct to say that the Earth is speeding away from the rocket. That's just the same set of events described from a different inertial frame).

 

[robinson]

The traveling twin changed his frame of reference by changing his velocity, not by changing his position.

Please don't say things like that.

 

[Tumbleweed]

If I am not mistaken, the only ones that will be the same, are those that travel at right angles to the earth thru that point.

>>>>>>>>>.>>>>>>>>>> the period is the fixed point



__________"E"arth


Paul

So if no one can agree on how far away something is, except for those in the same frame of reference, velocity-wise, Einstein did indeed screw up the whole universe