In recent times, [[physics]] and [[astrophysics]] have come to play a central role in shaping what is now known as [[physical cosmology]] by bringing observations and mathematical tools to analyze the universe as a whole; in other words, in the understanding of the universe through scientific observation and experiment. This discipline, which focuses on the universe as it exists on the largest scale and at the earliest moments, is generally understood to begin with the [[big bang]] (possibly combined with [[cosmic inflation]]) - an [[metric expansion of space|expansion of space]] from which the Universe itself is thought to have emerged ~13.7 ± 0.2 [[1000000000 (number)|billion]] (10<sup>9</sup>) years ago. From its violent beginnings and until its various speculative [[end of the universe|ends]], cosmologists propose that the history of the Universe has been governed entirely by [[physical laws]]. | In recent times, [[physics]] and [[astrophysics]] have come to play a central role in shaping what is now known as [[physical cosmology]] by bringing observations and mathematical tools to analyze the universe as a whole; in other words, in the understanding of the universe through scientific observation and experiment. This discipline, which focuses on the universe as it exists on the largest scale and at the earliest moments, is generally understood to begin with the [[big bang]] (possibly combined with [[cosmic inflation]]) - an [[metric expansion of space|expansion of space]] from which the Universe itself is thought to have emerged ~13.7 ± 0.2 [[1000000000 (number)|billion]] (10<sup>9</sup>) years ago. From its violent beginnings and until its various speculative [[end of the universe|ends]], cosmologists propose that the history of the Universe has been governed entirely by [[physical laws]]. |