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.
Death is only an old door Set in a garden wall; On quiet hinges it gives, at dusk When the thrushes call. Along the lintel are green leaves, Beyond, the light lies still; Very weary and willing feet Go over that sill. There is nothing to trouble any heart; Nothing to hurt at all. Death is only an old door In a garden wall.