Timeline for Twin paradox, with a meeting at a halfway point
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 27, 2015 at 19:41 | vote | accept | Quirk | ||
| May 24, 2015 at 12:47 | answer | added | ApproximatelyTrue | timeline score: 1 | |
| May 23, 2015 at 16:47 | comment | added | Quirk | To put this perhaps a little more broadly: if we can say "at the conclusion of B's journey, 8 years have passed for B and 10 for A", we are indicating a pair of singular points along the world lines of each. The case I am interested in is that of two voyagers passing A and B when each has reached those respective points, symmetrically travelling towards each other and meeting. | |
| May 23, 2015 at 16:32 | comment | added | Quirk | D passing B, and B reaching Z, are observed from body A at t0 + 16 years. At t0 + 10 years, body C passes A toward the meeting point equidistant between A and Z. The distance between A and Z remains 6 light years for the duration of the question. | |
| May 23, 2015 at 13:10 | comment | added | ApproximatelyTrue | The way you've stated the problem is still problematic. You say that simultaneously with B arriving at Z, A passes by C. However, in relativity, simultaneity is famously frame dependent - if two events do not occur at the same point in space, they can be simultaneous in one frame, but not simultaneous in the other. Thus, D passing B at the same time as B reaches Z is unambiguous (since they occur at the same point in space), but A passing C is not, and thus the offset measured depends on in which frame A passing C is simultaneous with B reaching Z. | |
| May 23, 2015 at 10:26 | comment | added | Quirk | @ApproximatelyTrue: Does it make a difference precisely which directions C and D are travelling, giving they're heading to meet at an equidistant point and must therefore have symmetric velocities? And yes, I mean a point equidistant between A and Z. | |
| May 23, 2015 at 5:40 | comment | added | ApproximatelyTrue | In which frame is D traveling at 0.6 c? It's also a little unclear which directions these bodies are traveling. Maybe specify velocities more clearly like such "at 0.6 c in the +x direction measured in A's frame of reference." Also, do you presumably mean the point that was equidistant between A and B at the time that C and D passed A and B? | |
| May 22, 2015 at 23:23 | review | First posts | |||
| May 23, 2015 at 5:53 | |||||
| May 22, 2015 at 23:20 | history | asked | Quirk | CC BY-SA 3.0 |