Only science fiction authors really 'know' what this term is supposed to mean. Have a look at some of my essays essays on hyperspace and faster than light travel. As an astronomer and a physicist, I can imagine using these hidden dimensions of space-time to characterize how fundamental particles and their forces operate, but I sure can't imagine using them physically to do anything. To me, it would be like using the fact that Mars is the color 'red' ( a hidden dimension we can use to distinguish it from other planets) to help us estimate its mass. Sometimes the concept of 'dimension' can have an obvious experimental meaning, but doesn't help us solve other problems.
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