This is a series of introduction to scientific universe for at least intermiate level education so that they can be introduced to the big ideas, understand topic as a whole, comprehensive but simple, avoiding details but exposing the source of the big ideas. At the level here, ideas appear to be orthogonal even though they turn out way after today to be interconnected.
Universe begins with a big bang that births time, though there are ekpyrotic models in which universe may have easier history and available impacts in our universe.
The universe <originated - how>, gave rise to<CMB|what's that science measure> expanded to current <size - how|astronomy sizes>, of 10^80 <objects- 17 quarks etc>.
What is the Big Bang Theory? The Big Bang Theory is the most widely accepted explanation for the origin of the universe. According to this theory, the universe began as a singularity, in quantum space, a point of infinite density and temperature. Created were mass and time. Gravity can be viewed as negative energy, in which case totals of mass in entire universe may be zero. Such creation are normal in Quantum mechanics with probability that varies inversely with mass and is a property of Quantum space. Quantum space can be one in infinity of fecund spaces in the multiverse.