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my intuition says this is impossible to detect as if space time is bent then all the equipment and our reality is bent along with it and thus we will be none the wiser.... ie we might be inside a bent reality but we and all our sensing equipment will still sense everything as straight.

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It's not bent the same in all directions. You can detect the difference in different directions, which is what LIGO does.

Your point, by the way, was hashed out in the early 1900s as part of the development of modern relativity. Physicists were well aware of the problem back then, and that's part of why it's so interesting and important that the speed of light turns out to be a constant.

A very simple counter example is that we can "see" the bend in spacetime made by the sun from how the earth makes a circular path around it, as opposed to going in a straight line.

LIGO just looks at the path (or rather just the length of the path) of photons.

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