|MLA Citation:||Bloomfield, Louis A. "Question 706"|
How Everything Works 19 Mar 2018. 19 Mar 2018 <http://howeverythingworks.org/print1.php?QNum=706>.
But this brings up one of the peculiar results of special relativity. From our perspective on earth, the explorers are moving quickly as they head toward the stars and their clocks appear to be running slowly to us. But from their perspective, we are moving quickly in the other direction and our clocks appear to be running slowly to them. This apparent paradox is resolved by the fact that the explorers would not agree with us on the ordering of two events occurring at different locations—space and time appear differently to us; they are intermingled. However, when the explorers accelerate in order to turn around and headed back toward us, their perceptions of space and time undergo a radical change. They see our clocks zoom ahead while we continue to see their clocks running fairly slowly. When the explorers finally returned to earth, their clocks indicate that they had been gone only a short time. However our clocks indicate that they had been gone at least as long as the time it would take light to complete the roundtrip. This situation leads to the famous "twin paradox," in which one twin travels through space while the other remains at home. When the explorer twin returns to earth, the explorer twin is still young but the earthbound twin is very old. If near-light-speed travel were to become possible (a very remote possibility), such twin paradoxes would certainly occur.