Can somebody explain me the twin's paradox in a simple language clearly?

Question

I will be very thankful.

Answer 1

One twin travels fast and far, turns around and returns. He's young. His twin on earth is old. Paradox: The *earth twin* traveled fast and far in the astronaut's frame, so why didn't the earth twin age more than the astronaut too? Well, they can't both be older than the other in the same place, so that's a paradox. Right?

Well, no. The solution actually has nothing to do with acceleration, per se. That's a common misunderstanding. It's who moves relative to earth's reference frame that stays young. You see, there's a hidden reference frame bias in the problem; the distance traveled is claimed to be far in both reference frames to make it sound like a paradox, while it's not, actually. In the astronaut's frame, he only travels a short distance from earth, so the trip only takes him a short time. This is due to Lorentz contraction of the galaxy (assume he's traveling its length and back). In earth's frame, however, the galaxy is not contracted, so the trip takes many many years, so earth twin ages.

Incidentally (this is for zero-percent mike), I actually do have a PhD in Physics, and have been a practicing physicist for 19 years since grad school, studying high energy density matter. By "pe se", I mean acceleration doesn't appear directly in the formal solution to the problem, just its final integrated value velocity) for use in the Lorentz Transformations out and back. Are you able to understand that, or do I need to simplify the explanation with hand puppets representing the twins?

Answer 2

there are 2 theories of relativity
simple relativity
& general relativity.

Simple relativity was discovered first in 1905.
the personal time of a fast moving object is slower than the personal time of a staionary object.
if you are in a space ship traveling very fast you will age slower.

The twins paradox is, if you stay on earth and you have a twin who goes in a spaceship very fast your twin will age slower than you.
The paradox is from the twins point of view it is you who is traveling very fast away from him/her and you should be the one ageing slowly.
The 2 points of view are correct acording to simple relativity but logic says that there is a problem you cant both age slower. This shows that there is an error in simple relativity.
The Error is acceleration, it is your twin who accelerated away from you so he/she is the one who has the slower personal time.
This was the first step for einstein in making the General theory of Relativity. It took him 11 years, a lot of help with his maths and a few amazing leaps of intuition. The biggest was that mathermaticly gravity is acceleration.

Answer 3

Someone wrote<< The solution actually has nothing to do with acceleration, per se. That's a common misunderstanding>>

The guy who wrote this just does not know what he is talking about.