Einstein can help: https://books.google.com/books/download/Relativity.pdf?id=3H46AAAAMAAJ&output=pdf https://books.google.com/books/download/Relativity.pdf?id=

Einstein can help: https://books.google.com/books/download/Relativity.pdf?id=3H46AAAAMAAJ&output=pdf https://books.google.com/books/download/Relativity.pdf?id=3H... His book was intended to help people understand these exact questions, without getting into any complex math. Regarding "how is this possible?": This was experimentally verified in the 70s in the Hafele–Keating Experiment. Read more here: https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experim...