Imagine a cubic volume of space, defined today, with edges of the order of the Planck length.(adsbygoogle = window.adsbygoogle || []).push({});

As cosmological time goes forward this volume expands so that the edges of the cube expand with the scale factor. This seems ok.

However, as physics is time-reversible, it should be valid to imagine time going backwards so that the edges contract with the scale factor.

But then they would be smaller than the Planck length. If the Planck length is the smallest length scale then is there a contradiction here?

**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!

# I Planck length and space expansion/contraction

Have something to add?

Draft saved
Draft deleted

Loading...

Similar Threads - Planck length space | Date |
---|---|

I Is the Planck length a proper length? | Aug 12, 2017 |

I Does the Planck length expand in a FRW universe? | Jun 5, 2017 |

Planck length and expansion | Aug 28, 2015 |

Big bang from planck length | Aug 26, 2014 |

Is the Planck Length real? How do we know? | Sep 15, 2010 |

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