These theories were based on the hypothesis that all the matter in the — Big Bang

"Bothers science because it clashes with scientific religion—the religion of cause and effect, the belief that every effect has a cause. Now we find that the biggest effect of all, the birth of the universe, violates this article of faith. . . . what came before the Big Bang is the most interesting question of all."

"We are privileged to be part of the first generation who can claim to have a respectable, rational, and coherent description for the creation and evolution of the universe. The Big Bang model offers an elegant explanation of the origin of everything we see in the night sky, making it one of the greatest achievements of the human intellect and spirit. It is the consequence of an insatiable curiosity, a fabulous imagination, acute observation and ruthless logic. Even more wonderful is that the Big Bang model can be understood by everyone."

"This circumstance of an expanding universe is irritating."

"In the beginning there was an explosion. Not an explosion like those familiar on earth, starting from a definite center and spreading out to engulf more and more of the circumambient air, but an explosion which occurred simultaneously everywhere, filling all space from the beginning, with every particle of matter rushing apart from every other particle. ‘All space’ in this context may mean either all of an infinite universe, or all of a finite universe which curves back on itself like the surface of a sphere. Neither possibility is easy to comprehend, but this will not get in our way; it matters hardly at all in the early universe whether space is finite or infinite. At about one-hundredth of a second, the earliest time about which we can speak with any confidence, the temperature of the universe was about a hundred thousand million (1011) degrees Centigrade. This is much hotter than in the center of even the hottest star, so hot, in fact, that none of the components of ordinary matter, molecules, or atoms, or even the nuclei of atoms, could have held together. Instead, the matter rushing apart in this explosion consisted of various types of the so-called elementary particles, which are the subject of modern high­energy nuclear physics."

"Once we overcome our fear of being tiny, we find ourselves on the threshold of a vast and awesome Universe that utterly dwarfs—in time, in space, and in potential—the tidy anthropocentric proscenium of our ancestors. We gaze across billions of light-years of space to view the Universe shortly after the Big Bang, and plumb the fine structure of matter. We peer down into the core of our planet, and the blazing interior of our star. We read the genetic language in which is written the diverse skills and propensities of every being on Earth. We uncover hidden chapters in the record of our origins, and with some anguish better understand our nature and prospects. We invent and refine agriculture, without which almost all of us would starve to death. We create medicines and vaccines that save the lives of billions. We communicate at the speed of light, and whip around the Earth in an hour and a half. We have sent dozens of ships to more than seventy worlds, and four spacecraft to the stars. We are right to rejoice in our accomplishments, to be proud that our species has been able to see so far, and to judge our merit in part by the very science that has so deflated our pretensions."

"The Big Bang understood as the event that created the hot, dense gas of cosmic matter was not an explosion starting from a point in space. If it had been, we could detect traces of that initial point today. Instead, astronomical observations teach us that the primordial matter gas was incredibly uniform and homogeneous. This indicates that the universe in its infancy was like a giant pot of well-mixed soup. The Big Bang is the event in which this soup was created, not at any special point, but homogeneously everywhere in the pot. It is a uniform transition that involved a very large, perhaps even infinite, region of space that was suddenly filled with matter. Understanding the Big Bang means understanding what caused this transition."{{NDR|And before the Big Bang, what was there?} Today it is thought that before the Big Bang there was only empty space. A very special empty space, however. There was no matter, but the fabric of space was imbued with a form of energy called precisely vacuum energy capable of exerting repulsive gravity. The effect is quite amazing because it is the exact opposite of the force of gravity we are used to, which can only attract material bodies."