The Twin Paradox is a thought experiment commonly used to illustrate the effects of time dilation in special relativity. It involves two twins, one who stays on Earth (the stationary twin) and one who goes on a high-speed round trip through space (the traveling twin). When the traveling twin returns to Earth, they find that less time has passed for them compared to the stationary twin, resulting in the so-called paradox.
The resolution to the Twin Paradox lies in the fact that the traveling twin must undergo acceleration and deceleration to change their direction and return to the reference frame of the stationary twin. It is during these periods of acceleration and deceleration that the traveling twin experiences time dilation.
When the traveling twin accelerates or decelerates, their reference frame changes, and they are no longer in a state of constant velocity. During this non-inertial motion, time dilation effects occur. The acceleration and deceleration experienced by the traveling twin cause their time to slow down relative to the stationary twin. Thus, the paradox is resolved.
The crucial point is that the traveling twin's reference frame changes due to acceleration and deceleration, which leads to time dilation during those periods. However, when the traveling twin is in a state of constant velocity (between acceleration and deceleration phases), they experience less time passing compared to the stationary twin.
In summary, while acceleration and deceleration can indeed cause time dilation, the Twin Paradox is resolved by considering the change in reference frames during the periods of acceleration and deceleration. It is the difference in the reference frames and the associated time dilation effects that explain the observed time difference between the traveling and stationary twins.