This book will take you on a journey through our physical universe, based on current, established science. The journey starts with the simplest fundamental particles, such as quarks and electrons, and ends with the most complex of all material objects – our human brains.Our universe has evolved through forming communities of things, with simpler things coming together in new groupings to make more complex things. So, every “thing” in the universe is a community of things, and at every level a community is greater than the sum of its separate parts.If we view the universe in terms of communities, it takes the form of a hierarchy of eight levels of communities, from protons and neutrons to human societies. And at every level in this universal hierarchy, the communities are bound together by ceaseless interactive exchanges.So, our universe reveals itself as a dynamic hierarchy, sustained by endless exchanges between members of the communities at every level. Each of us is the universe in microcosm, for we each embody all eight levels of the universal hierarchy.It is through things coming together and forming communities that the universe, with us now in it, has come to be what it is.Andrew McNeil has a PhD in metallurgy. He first worked in university research and then, for twenty years, he taught secondary school science.