I'm jelly. gy kitch constantly has tumbleweeds in it..
That theory sounds like it has no sauce.
Increasing entropy, something something, . etc etc..
Heat happens with compression, not expansion. An expanding universe will never heat.
canned [anygas] will do.
go top off your car's ac and tell me how slowly the can cools off.
You are inserting a gas into a vacuum, if the ac unit is properly empty before filling with the refrigerant; properly filling one requires the unit to be able to hold a vacuum.