Understanding the Twin Paradox: A Simple Explanation

In summary: This is not the thread for that. If you want to know about time dilation, you should start by reading about it on your own and then asking questions specific to that topic. In summary, the twin paradox is an issue where two identical twins who are traveling to different parts of the universe see different ages pass by on Earth due to the effects of relativistic time dilation.
  • #1
ranjitnepal
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0
Please explain me simply about twin paradox..
 
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  • #2
Hey, I was also thinking about starting a similar thread, but since it's already started I'll ask a straight-forward question that must be regarded here, why does the traveling twin see the clocks on the Earth (the twin that stayed at home) move slower, while less proper time elapses for mih. Shouldn't he see the twin that stayed at Earth age faster, and not slowe?
 
  • #3
ranjitnepal said:
Please explain me simply about twin paradox..

Google will find you one of the many excellent explanations online. I suggest you read some of these and then come back with more specific questions about any parts that you don't understand - you'll get better answers more quickly that way.

You could do worse than starting here:
http://www.physics.adelaide.edu.au/~dkoks/Faq/Relativity/SR/TwinParadox/twin_paradox.html
 
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  • #4
analyst5 said:
Hey, I was also thinking about starting a similar thread, but since it's already started I'll ask a straight-forward question that must be regarded here, why does the traveling twin see the clocks on the Earth (the twin that stayed at home) move slower, while less proper time elapses for mih. Shouldn't he see the twin that stayed at Earth age faster, and not slowe?

You'll find a good answer in previous threads on this forum. One of ghwellsjr's spacetime diagrams explaining the twin paradox in terms of relativistic Doppler is what you're looking for.

And I already pointed to http://www.physics.adelaide.edu.au/~dkoks/Faq/Relativity/SR/TwinParadox/twin_paradox.html elsewhere in this thread - pay particular attention to the section on the "Doppler Shift Analysis"
 
  • #5
ranjitnepal said:
Please explain me simply about twin paradox..
Start with the concept of an Inertial Reference Frame (IRF), as system of spatial and time coordinates, that allow you to specify when and where each twin is. Then for any twin that is moving, time progresses more slowly compared to the Coordinate Time of the IRF, the faster he moves, the slower his time progresses. So if both twins start out together at rest in the IRF but then one of them moves away and comes back, the one that moved will have elapsed less time the the one that stayed put. Simple, isn't it?
 
  • #6
analyst5 said:
Hey, I was also thinking about starting a similar thread, but since it's already started I'll ask a straight-forward question that must be regarded here, why does the traveling twin see the clocks on the Earth (the twin that stayed at home) move slower, while less proper time elapses for mih. Shouldn't he see the twin that stayed at Earth age faster, and not slowe?
If you draw the motions of the twins in a diagram of an IRF, you can also draw in the light signals that depict what each one sees and your answers will be clear as a bell. I have already invited you in one of your other threads to specify a scenario and I will do all the work for you but you still have not taken me up on my offer. If it is just a simple twin scenario, you can do a search on my name for the word "diagram" and you will find lots that already depict the twin scenario and answer your questions. Please do that before asking for one that is only insignificantly different.

But to answer your question: the traveling twin will see the Earth twin age more slowly than himself on the outbound portion of his trip but more quickly on the inbound portion and it is the sum of the two that ends up with the traveling twin seeing the Earth twin age more for the entire trip. Haven't we gone over this before in one of your threads, including Durant's threads that I linked to?
 
  • #7
ghwellsjr said:
If you draw the motions of the twins in a diagram of an IRF, you can also draw in the light signals that depict what each one sees and your answers will be clear as a bell. I have already invited you in one of your other threads to specify a scenario and I will do all the work for you but you still have not taken me up on my offer. If it is just a simple twin scenario, you can do a search on my name for the word "diagram" and you will find lots that already depict the twin scenario and answer your questions. Please do that before asking for one that is only insignificantly different.

But to answer your question: the traveling twin will see the Earth twin age more slowly than himself on the outbound portion of his trip but more quickly on the inbound portion and it is the sum of the two that ends up with the traveling twin seeing the Earth twin age more for the entire trip. Haven't we gone over this before in one of your threads, including Durant's threads that I linked to?

Actually, I've never asked you a thing about time dilation and this is the first time. My questions on previous threads were related to other relativistic effects. But thank you indeed for the appropriate answer.
 
  • #8
analyst5, please don't hijack other people's threads.

ranjitnepal, please put in some effort before you ask others to do so. This topic has been discussed at length here: https://www.physicsforums.com/search.php?searchid=3774972 [Broken]
 
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What is the twin paradox?

The twin paradox is a thought experiment in the theory of relativity that explores the concept of time dilation. It involves a pair of twins, one of whom travels at high speeds through space while the other stays on Earth. When the traveling twin returns, they find that they have aged less than the twin who stayed on Earth, despite the fact that they experienced the same amount of time.

How does the twin paradox relate to the theory of relativity?

The twin paradox highlights the effects of time dilation, which is a key concept in the theory of relativity. According to this theory, time is not absolute and can be affected by factors such as speed and gravity. The twin paradox demonstrates how time can pass differently for individuals based on their relative motion.

Is the twin paradox a real phenomenon?

No, the twin paradox is a thought experiment and has not been observed in real life. However, the principles behind it have been confirmed through numerous experiments and observations, such as the famous Hafele-Keating experiment. This thought experiment helps to illustrate the implications of the theory of relativity.

What are some potential solutions to the twin paradox?

One possible solution to the twin paradox is that the traveling twin experiences acceleration and deceleration, which can affect their perception of time. Another solution is that the traveling twin experiences more gravitational time dilation due to their velocity. Both of these factors could contribute to the discrepancy in aging between the twins.

Are there any real-life applications of the twin paradox?

The principles behind the twin paradox have real-life applications in fields such as space travel and GPS technology. For example, GPS satellites must account for time dilation effects in order to accurately determine the positions of objects on Earth. The twin paradox also helps us to understand the effects of high-speed travel on the aging process.

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