So what exactly is beyond our atmosphere, like space, has anybody actually been in space or are we just making hopeless fantasies

The universe, milky Way even black holes. Yes the first people who went to the moon put a flag to represent America. We are not making hopeless fantasies.

Explanation:

i think it because equal matrices have equal dimensions, only square matrices can be symmetric. for all indices and . every square diagonal matrix is symmetric, since all off-diagonal elements are zero. in linear algebra, a real symmetric matrix represents a self-adjoint operator over a real inner product space.

the answer is mosques. they are an important part of islamic culture.