our Universe is a spherical region with Earth at the center. The stuff near the edges of our Universe, from which light has only now reached us after a 14-billion-year space journey, is currently about 5 × 1026 meters away from us.1 As far as we currently know, our Universe contains about 1011 galaxies, 1023 stars, 1080 protons and 1089 photons (particles of light).
