"Dark matter has a gravitation effect on other objects. You can't see it, you can't feel it, but you can watch something being pulled in its direction."

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However, one new theory says that dark matter may be ordinary matter in a parallel universe. If a galaxy is hovering above in another dimension, we would not be able to see it. It would be invisible, yet we would feel its gravity. Hence, it might explain dark matter.

— Michio Kaku