Register to reply 
Twin paradox and time dilation. 
Share this thread: 
#1
Apr308, 01:07 AM

P: 59

When we read that two twins would age differently when one moves with relativistic speeds.
i.e. When one twin travels at speed near to speed of light then the twin on earth would see that time for the travelling twin has slowed down. Thats what we say time Dilation. Similar is the case with the other twin. He may also say on returning back that time had slowed for the twin on earth. But his claim is refused because he was initially and finally in a non inertial frame. But what about the time when he was moving with constant velocity. At that time he was moving in an inertial frame. Why does it happen then that what he sees is false and the OP is true?? 


#2
Apr308, 01:58 AM

Sci Advisor
P: 8,470




#3
Apr308, 05:06 AM

P: 2,043




#4
Apr308, 05:11 AM

Sci Advisor
P: 8,470

Twin paradox and time dilation.



#5
Apr308, 05:22 AM

P: 2,043




#6
Apr308, 05:30 AM

Sci Advisor
P: 8,470

For a numerical example, consider the same situation first viewed from the rest frame of the inertial stayathome twin (call this frame A), next viewed from the inertial frame where the traveling twin is at rest between leaving Earth and turning around (call this frame B). If both twins are exactly 30 when the traveling twin departs the stayathome twin, and in the stayathome twin's frame A, the traveling twin moves away for 10 years at 0.6c before instantaneously accelerating to come to rest relative to the stayathome twin, then in frame A the stayathome twin turning 40 will happen simultaneously with the traveling twin accelerating while turning 38. But in the frame B of an inertial observer who sees the traveling twin at rest until accelerating, the stayathome twin is moving away at 0.6c for 8 years before the traveling twin accelerates (again at age 38) to match speeds with him, and at the moment of acceleration the stayathome twin is 36.4 years old. This is just an example of the relativity of simultaneity. Both frames agree the traveling twin is turning 38 at the moment of acceleration, but in the first frame A this event is simultaneous with the stayathome twin turning 40, while in the second frame B this event is simultaneous with the stayathome twin turning 36.4. If you doubt these numbers are correct, I can show that they are by using the Lorentz transformation, if you wish. 


#7
Apr308, 05:53 AM

P: 2,043

1. Twin A and B on planet P and point X, a fixed distance away from planet P. 2. A accelerates away from P towards X. 3. A accelerates towards P to stop at X. 4. A records the total elapsed time since 2. 5. A accelerates away from X towards P. 6. A accelerates towards X to stop at P. 7. A records the total elapsed time since 5. Then all observers must agree on both recorded proper times recorded in step 4 and 7. 


#8
Apr308, 06:12 AM

Sci Advisor
P: 8,470




#9
Apr308, 08:45 AM

P: 2,043




#10
Sep2808, 11:54 AM

P: 9

Interesting is that screenwriters for Flash Gordon in 1950's (West Berlin production) had "Flash" testing a machine which would theoretically allow Flash to travel faster than the speed of light. Dale quips,(summary) "...you'll be travelling so fast that you'll be arriving before leaving."
What physics principle were the screenwriters incorporating in that segment? Thank you.  


#11
Sep2808, 01:14 PM

Sci Advisor
P: 8,470




#12
Sep2808, 02:37 PM

Emeritus
Sci Advisor
PF Gold
P: 9,279

...or this thread.



Register to reply 
Related Discussions  
Symetry, time dilation, twin paradox and all that stuff  Special & General Relativity  32  
RTT’s mind boggling Time Dilation Paradox  Special & General Relativity  16  
Time Dilation Paradox  Special & General Relativity  3 