The twin paradox proved that Einstein's special theory of relativity is not relativity at all.
Scientists have debated this for over 100 years, but there is no answer.
Ngo Quang Ha re-examined the step-by-step construction of the Lorentz transformation formula and discovered errors in the construction process, which led to the violation of symmetry in the special theory of relativity..
Thus, the twin paradox was correct, and Einstein's special theory of relativity was wrong.
The research results were presented by Ngo Quang Ha in book "The universe is a unified object" with very detailed mathematical proofs.
The book (in English) is available on Amazon: https://www.amazon.com/dp/B0HCGYPFK1