soon after einstein came up with his special theory of relativity — where he said that time and space have to be unified. you can't talk about three—dimensional space and one—dimensional time as though they're separate things. they're part of one four—dimensional space time. so, the block universe is a bit like... imagine space was only flat — only two—dimensional, and then the third dimension is time. so, think of a loaf of bread. the time axis is along the length of the loaf and space are the individual slices. the block universe says that it's notjust the present time that exists. the past hasn't gone and been forgotten — and the future hasn't yet to be decided. in the block universe, all times co—exist. they're just different slices of the loaf. there is no universal present moment. in this scenario, it doesn't matter which of the domino