1. Originally Posted by Motor Daddy
Tach, we all know that SR says that the elapsed times are different for each twin. rpenner already posted the correct answers, that the total round trip distance traveled is 20 light-seconds, the total elapsed time for the stay at home twin is 60 seconds, and the total elapsed time for the traveling twin is approximately 51.0184 seconds.

I explained to you here that prior to the traveling twin's departure the twins placed a mirror a distance of 1 light-minute away from the coordinate (0,0,0) where the twins are at departure and return. The light was emitted at t=0 when the traveling twin starts his journey. When the traveling twin returns, the traveling twin is in the same location and same inertial frame as the stay at home twin. Immediately upon return he starts his stop watch.

How much time elapses on the traveling twins stop watch from the time he starts it upon reuniting with his twin, to the time the light returns from the mirror to the twins position (0,0,0)?

Answer my direct question, Tach. How much time elapses while the twins are standing there waiting for the light to return to them?
The light returns in two minutes.
Since the total elapsed proper time for the "stay at home" twin is 1 minute, he sees the light back 1 minute after the reunion with the "traveling" twin.
Since the total elapsed proper time for the "traveling" twin is approximately 51.0184 seconds he sees the light back approximately 1 minute and 9 seconds after the reunion with the "stay at home" twin.
Totally irrelevant wrt the rest of the problem. Why do you always have to bring in your fixation with "light spheres"?

2. Originally Posted by Tach
The light returns in two minutes.
Since the total elapsed proper time for the "stay at home" twin is 1 minute, he sees the light back 1 minute after the reunion with the "traveling" twin.
Since the total elapsed proper time for the "traveling" twin is approximately 51.0184 seconds he sees the light back approximately 1 minute and 9 seconds after the reunion with the "stay at home" twin.
Totally irrelevant wrt the rest of the problem. Why do you always have to bring in your fixation with "light spheres"?

The twins are standing next to each other waiting for the light to return. They both start identical stop watches, simultaneously. You are saying the twin that previously traveled says his stop watch says 1 minute and 9 seconds when the light returns, and the stay at home twin's stop watch says exactly one minute when the light returns.

Is that your story? Are you sticking to it? Two identical stop watches in the same frame, started simultaneously, stopped simultaneously, and one reads 1 minute and 9 seconds and the other reads exactly 1 minute.

So, two people in the same frame using the same watch disagree on what the speed of light is?

The stay at home twin says the speed of light is 299,792,458 m/s, and the twin which previously traveled says the speed of light is 260,689,094 m/s??

3. Originally Posted by Motor Daddy

The twins are standing next to each other waiting for the light to return. They both start identical stop watches, simultaneously. You are saying the twin that previously traveled says his stop watch says 1 minute and 9 seconds, and the stay at home twin's stop watch says exactly one minute.

Is that your story? Are you sticking to it? Two identical stop watches in the same frame, started simultaneously, stopped simultaneously, and one reads 1 minute and 9 seconds and the other reads exactly 1 minute.

So, two people in the same frame using the same watch disagree on what the speed of light is?

The stay at home twin says the speed of light is 299,792,458 m/s, and the twin which previously traveled says the speed of light is 260,689,094 m/s??
This is exactly due to the fact that the twin that traveled shows a trip travel time of 51s while the twin left behind claims a trip travel time of 60s. Why do you have so much difficulty with this? Is it because you really, really hate relativity and you spend all your time in futile attempts trying to "disprove" it?

4. Originally Posted by Tach
This is exactly due to the fact that the twin that traveled shows a trip travel time of 51s while the twin left behind claims a trip travel time of 60s. Why do you have so much difficulty with this? Is it because you really, really hate relativity and you spend all your time in futile attempts trying to "disprove" it?
The trip was in the past. I asked you how much time elapses when they are standing next to each other, in the same frame, start identical stop watches simultaneously, stop them simultaneously when the light returns, how much time do their stop watches read.

Tach, you've dug yourself into a hole. Confucius say, when stuck in hole, STOP DIGGING!

5. Originally Posted by Motor Daddy
The trip was in the past. I asked you how much time elapses when they are standing next to each other, in the same frame, start identical stop watches simultaneously, stop them simultaneously when the light returns, how much time do their stop watches read.
This is not how you presented the problem.
If the above is what you want, both watches show 2 minutes. So, once again, what does all this have to do with the twins paradox? Hint: nothing.

6. Originally Posted by Tach
The light returns in two minutes.
Since the total elapsed proper time for the "stay at home" twin is 1 minute, he sees the light back 1 minute after the reunion with the "traveling" twin.
Since the total elapsed proper time for the "traveling" twin is approximately 51.0184 seconds he sees the light back approximately 1 minute and 9 seconds after the reunion with the "stay at home" twin.
Totally irrelevant wrt the rest of the problem. Why do you always have to bring in your fixation with "light spheres"?
Once the twins are reunited in the same frame, the traveling twin will have an accumulated time offset, but being in the same frame will now count time between reunion and light events in that frame at the same rate as the other.

7. Originally Posted by Tach
This is not how you presented the problem.
If the above is what you want, both watches show 2 minutes. So, once again, what does all this have to do with the twins paradox? Hint: nothing.
No they do not both show two minutes. The mirror was 1 light minute away. The light has to travel 2 light minutes to go from the point is was emitted, to the mirror, and back to the point it was originally emitted. The stay at home twin starts his stop watch simultaneously when the twin that previously traveled starts his stop watch, after his journey, when the twins were standing next to each other , side by side, not in relative motion to one another, in the same frame. They stop their watches simultaneously when the light returns to their position.

The twin that did not travel says his watch says exactly 60 seconds, from the time the traveling twin returned home until the light returns. You say the twin that previously traveled, says his stop watch reads 1 minute and 9 seconds from the time they simultaneously started their watches in the same frame, side by side, waiting for the light to return, until the light returned to their position. Hence, you are saying that two identical stop watches, started simultaneously in the same frame, side by side read two different times when stopped simultaneously. Therefore, you are saying two people with the same watches say light takes two different amounts of time to travel one distance in that frame.

Stop digging, Tach. You are going nowhere!

8. Originally Posted by Motor Daddy
No they do not both show two minutes. The mirror was 1 light minute away. The light has to travel 2 light minutes to go from the point is was emitted, to the mirror, and back to the point it was originally emitted. The stay at home twin starts his stop watch simultaneously when the twin that previously traveled starts his stop watch, after his journey, when the twins were standing next to each other , side by side, not in relative motion to one another, in the same frame. They stop their watches simultaneously when the light returns to their position.
Then, both twins clocks show 2min. You are not only confused about relativity, you are confused about basic physics. Besides, your example, has nothing to do with the twins paradox.

9. Originally Posted by Tach
Agreed. If you're not accounting for a time offset it has nothing to do with the twin "paradox". Just a completely trivial scenario.

10. Originally Posted by Syne
Once the twins are reunited in the same frame, the traveling twin will have an accumulated time offset, but being in the same frame will now count time between reunion and light events in that frame at the same rate as the other.
If that is the case, the clocks show the times 60s and 69s, respectively, as I already answered.
But MD now claims that the clocks are started simultaneously, so they both show 120s. Either way, the nonsense he's been posting has nothing to do with the twins paradox.

11. Originally Posted by Tach
Then, both twins clocks show 2min. You are not only confused about relativity, you are confused about basic physics. Besides, your example, has nothing to do with the twins paradox.
Are you really not getting this??

The twin that stayed home starts a stop watch when the twin that previously traveled returns from his trip. How much time does the stop watch read if he stops it when the light returns?

12. Originally Posted by Syne
Agreed. If you're not accounting for a time offset it has nothing to do with the twin "paradox". Just a completely trivial scenario.
We are dealing with a person (MD) that has a looong history of posting total nonsense in his vain attempts at "disproving" relativity.

13. Originally Posted by Tach
We are dealing with a person (MD) that has a looong history of posting total nonsense in his vain attempts at "disproving" relativity.

14. Originally Posted by Motor Daddy
Are you really not getting this??

The twin that stayed home starts a stop watch when the twin that previously traveled returns from his trip. How much time does the stop watch read if he stops it when the light returns?

15. Originally Posted by Tach
I've changed NOTHING! You are now understanding your error and don't have an explanation. Answer my question.

16. Originally Posted by motor daddy
i've changed nothing! You are now understanding your error and don't have an explanation. Answer my question.
lol

17. Originally Posted by Tach
lol

18. Originally Posted by Motor Daddy
Time for you to stop trolling this thread, whatever your fixation with light spheres has nothing to do with the twins paradox.

19. Originally Posted by Tach
Time for you to stop trolling this thread, whatever your fixation with light spheres has nothing to do with the twins paradox.
I've incorporated a system of checks and balances into the twin PARADOX, and it's called the light sphere, and the light sphere NEVER lies!

So, according to you, two twins start identical stop watches, simultaneously, when one twin returns home from a journey. They stop their watches simultaneously. During the entire duration of time that the stop watches were ticking the twins remained in the same frame, side by side, no relative motion the entire duration, and yet you say one stop watch reads 1 minute and 9 seconds and the other watch reads exactly 1 minute.

HOW CAN THAT BE, TACH???

20. Originally Posted by motor daddy
i've incorporated a system of checks and balances into the twin paradox, and it's called the light sphere, and the light sphere never lies!
lol

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