Then we decide which is bigger. Our travels inside take us to the vanishingly small. Those outside reach to immense spaces of an expanding Universe. We start small.
Few people can visualize an atom.
The Theory of Superstrings holds that quarks are tiny strings with a characteristic length of 10 -35 meters . We know no smaller particle than the quark. Now let's go outside the atom and to the stars. Much is left to discover, however, both Inside and Outside the Atom.