Hello,(adsbygoogle = window.adsbygoogle || []).push({});

I have a question about the character of the universe today and its early state.

As I understand it there is no consensus as to whether the universe today (the whole universe, not the observable) is infinite, finite, or finite but looped in on itself. It seems to me to follow that if (and it's a big if) the universe is infinite now, and has been expanding at finite rates for a finite amount of time, then it has always been infinite, even a split second after the big bang.

What confuses me is that I see many respected physicists and periodicals talking about the very early universe and talking of an "infinitessimally small dense hot point", and confidently stating the size of the universe say a second after the big bang as if this didn't imply that by doing so they are necessarily stating that they do not therefore believe the universe is infinite today - unless I've misunderstood what I've put in the paragraph above.

Is that right? It seems to me that all we can say about the early universe (in order to avoid necessarily taking a position on the size of the universe today) is that the universe at the big bang was infinitely dense, that the space between points was infinitely small. That doesn't mean it was an infinitely small point however, nor that it couldn't still be a singularity. After all the distance between all points can still start expanding in an infinitely large space just as easily as it can in a single point.

Do you agree with my understanding? Many thanks.

**Physics Forums - The Fusion of Science and Community**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Infinite universe from a finite start

Loading...

Similar Threads - Infinite universe finite | Date |
---|---|

B How can the Universe be infinite and yet have a finite age? | Aug 27, 2016 |

B Does the Universe have finite or infinite size? | Mar 20, 2016 |

I Simply Cannot Understand Olbers' Paradox -- Finite/Infinite Universe | Jan 14, 2015 |

Infinite universe but finite beginning? | Jul 23, 2014 |

Universe finite or infinite during the first instance of inflation? | Oct 24, 2013 |

**Physics Forums - The Fusion of Science and Community**