價格：免費
檔案大小：9 MB
版本需求：需要 iOS 11.0 或以上版本。與 iPhone、iPad 及 iPod touch 相容。
支援語言：英語
Time travel tnto the future is possible. If you were to leave Earth in a spacecraft travelling at an appreciable fraction of lightspeed, turn around and come back, only a few years might have passed on board but many years could have gone by on Earth. This is known as the “twins paradox”.
支援平台：iPhone, iPad