Relativity has little practical relevance in our real nontheoretical environment. Its founding premise, light's (presumed) constancy, is conceptually impossible. It only works theoretically in the one dimension of linear motion and only in one direction. In three dimensions it's inherently conflicted. In reality, its velocity can only compound mechanically with the motion of its source. This is what all of the Michelson-Morley type experiments actually show. And that's in addition to its factual variability that Einstein also asserts despite the invalidating contradiction. With an underlying premise that's altogether unworkable, relativity becomes untenable as well. Its other components that aren't necessarily dependent on light's (presumed) invariance are just as conflicted and innately unworkable. Its four-dimensional "space-time" is inconceivable, and it impossibly curves two-dimensionally underneath three-dimensional massive bodies to facilitate their "attraction." Its "principle of equivalence" impossibly has acceleration's one-dimensional uniform reaction and rotation's two-dimensional dispersive reaction equal to gravity's three-dimensional runaway coalescing/condensing. Its "finite and yet unbounded" universe, that with expansion has become the big bang, is strictly theoretical as well. To maintain its observed uniformity, it expresses two-dimensionally, like the surface of a sphere. So it's also not real. With relativity's manifest impracticality and the purely theoretical nature of its fundamental constituents, nearly all of it can be factually qualified as useless.