<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Arrow_of_time" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Arrow_of_time</a><p>If you go to the &#x27;overview&#x27; section, there is a nice snippet explaining all this. It points out that gravity works fine in a universe that is running backwards, however entropy is decreasing instead of increasing.