Viewing a (giant) clock at relativistic speed

[TumblingDice]

@ghwellsjr - Thank you for your reply. I never had a problem using a 3 light year milestone - only that this was not the same as the OP asked, and would be an added prerquisite to the setup that mr4 referred to as simpler, without mentioning thie significance it would add to the preparation.

I am talking about a MUCH simpler scenario than you describe above, in the sense that my reference frame doesn't enter into the calculations at all! Let's see if I can be clearer. I set off from the clock as it reads t = 0 and travel at 0.6c (observing rods & clocks through a porthole) until I reach the 3ly milestone.

Might there be a problem nailing down a 3ly milestone between both observers? I'm wondering if your simpler scenario requires a more complex set of prerequisites to maintain its integrity. Would the observers be required to mark this milestone in advance so both can agree on the same location?

ghwellsjr wrote:

The clock at the milestone has been previously synchronized to the "stationary" clock and they both read the same value as the Coordinate Time.

The OP has been derailed. The simpler scenario is a different animal than the OP. Now you have replied by supporting why the "supposedly simpler" scenario is accurate. My exceptions have not been about accuracy of the scenario. My concern is that it's more confusing than helpful, providing the OP with an answer to a question that's different than that being asked, and leaving out important requirements, too. It certainly isn't simpler if it requires locating and synchronizing two clocks three light years apart in advance.

This may be a case of posting without reading enough to understand the thread's evolution first. George, I'm really sorry that I've taken up your time with the space diagram and all, and I do appreciate the effort! This is just getting further off topic the harder I try, so maybe best for me to let it go...

<sigh>

 

[m4r35n357]

I have recently wrestled with the precisely the question in the title and the OP myself, so I answered them as they were both written, with the answer I would have liked to read myself to the same question. OK I slipped up quoting the actual message, but tripped up over the new interface (the quote is there in the previous message). I just wanted to share a moment of clarity with a fellow learner. I still think I answered #1 and the thread title more accurately than the following discussion (again, speaking from the viewpoint of a learner).

 

[ghwellsjr]

@ghwellsjr - Thank you for your reply. I never had a problem using a 3 light year milestone - only that this was not the same as the OP asked, and would be an added prerquisite to the setup that mr4 referred to as simpler, without mentioning thie significance it would add to the preparation.
...
The OP has been derailed. The simpler scenario is a different animal than the OP. Now you have replied by supporting why the "supposedly simpler" scenario is accurate. My exceptions have not been about accuracy of the scenario. My concern is that it's more confusing than helpful, providing the OP with an answer to a question that's different than that being asked, and leaving out important requirements, too. It certainly isn't simpler if it requires locating and synchronizing two clocks three light years apart in advance.

This may be a case of posting without reading enough to understand the thread's evolution first. George, I'm really sorry that I've taken up your time with the space diagram and all, and I do appreciate the effort! This is just getting further off topic the harder I try, so maybe best for me to let it go...

<sigh>

It would be awfully boring for me if people didn't ask for spacetime diagrams, either directly or indirectly, and I appreciate the feedback.

But the OP did ask in his first post about a solution related to distance and unrelated to speed which none of us except mr4 addressed:

It should also show a recoverable component of slowing while moving away (that you could regain as an apparent quickening while moving back towards it) due simply to your growing or shrinking distance from it and regardless of your speed.

And if you look at his description of his program in post #14 that he is concerned about distance:

dist is the rest frame distance to target

To me, the problem is that the OP didn't say precisely what he wanted in his first post and he asked about issues that appeared off base (the recoverable component of time). This happens all the time with people who are trying to learn SR and the variation of responses in this thread is typical. I just wish the OP would come back and provide more feedback because without that, we are all trying our best to interpret what we think he wants.

 

[TJonline]

The algorithm that I presented above agreed exactly with the there and back scenario given below (please don't delete link as inappropriate, mysterious Mentor, and if you do, please say why you consider it inappropriate). The difference between clock and pocketwatch when the observer finally gets back to the clock and comes to an instantaneous stop were exactly the same. It might be erroneous to assume that what the clock reads to the observer during the journey is thus also correct, but I don't think so.

http://en.wikipedia.org/wiki/Twin_paradox

4 light years one way as measured in clock (rest) frame, v=0.8 c (instantaneous acceleration), clock and pocketwatch time upon return: 10 and 6 years

It also agreed pretty well with the one in the text in the page below. The error I attribute to approximation errors in the data they provided:

http://www.pbs.org/wgbh/nova/einstein/hotsciencetwin/

25 light years one way, v=0.9999 c, clock and pocketwatch time upon return - algorithm: 50 and 0.704 years, in text: 50 and 0.5 years

The algorithm agreed not at all well with the shockwave demo on the same page.

4.2 light years one way (Proxima Centauri), v=0.5 c, clock and pocketwatch time upon return - algorithm: 16.811 and 14.486 years, shockwave: 47.30 and 40.96 years. Be sure to subtract off the two fellows' starting ages (assume both were just born at the start of one's journey). Maybe that demo assumed something other than instantaneous acceleration. Who knows?

Thanks.