Perhaps what truly doesn’t exist is this ‘nature’ thing you refer to that, as you put it, “cannot calculate durations.” I experience ‘space’ and ‘time’ and so do you. Which tells me that space and time do exist if only in terms of experience. As experience is relative, so too space and time. So too our ‘universe.’ Goodbye objective universe: hello experience as a ‘building block’ of all we know and can know.