This number, known as the Hubble constant, describes the acceleration of the stretching of spacetime.

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This essentially means that metamaterials can be used to mimic our spacetime, as well as many others.

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For example, we know now that the spacetime we live in is non-Euclidian.

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This might not sound like much, until we understand that it has been theorised that the way in which they do so is similar to how spacetime manipulates light in general relativity.

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