In general relativity, time is considered a dimension like height, width and depth, creating a fourdimensionaluniverse called space-time.
在广义相对论中,时间被看作和长宽高一样的维度,并与它们构成了一个四维宇宙—被称作时空。
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Its description of time travel in a four-dimensionaluniverse presaged the cottage industry in theoretical space-time machines that has sprung up among physicists in recent decades.