I suspect that Nick is referring to a situation somewhat similar to the increase or decrease of energy due to pressure fluctuations within a vessel.
If you have a container and pump gas into it, the container will become warmer due to the increase in kinetic energy of the molecules that are inside, alternately if you allow the pressurized gas to escape from the container the kinetic energy content decreases and the temperature goes down.
If you consider the universe as a container where the gasses and mass are continually moving, then the areas that are expanding are becoming colder and the areas that are compressing are becoming warmer.
Since you asked for a URL, I’ll offer one, it is:
http://space-religion.com/More_of_the_theory.php
I must warn you though, the subject matter is controversial and many people have wilfully refused to study the concepts.
If you fall into that category, do not despair, you are not alone.:-}
Space/Science » in reply to re: Expansion of the Universe
re: I’m not sure but……..