theory of (general) relativity (20世纪初由爱因斯坦等建立和发展起来) 爱因斯坦这样描述～：“把你的手放在火炉上一分钟，似乎长达一小时；与一位漂亮的姑娘在一起坐一小时，似乎只有一分钟。这就是～。”Einstein described relativity this way:“Put your hand on a hot stove for a minute,and it seems like an hour.Sit with a pretty girl for an hour,and it seems like a minute.That’s relativity.”