From what I've been told, the temperature in space is approx. 3oK if not in direct contact with infrared rays from the sun/stars etc. This temperature is also decreasing as the universe expands. Space is also a vacuum, with very few particles per cubic unit. My question is: If space is a vacuum and a point in space is completely blocked by objects so that no infrared radiation is in direct or indirect contact (reflections etc.) and there are no particles in the vicinity, why is it that the temperature is not absolute zero? Where does this tiny temperature come from? Also, if a vacuum were created here on Earth, would it also be the same temperature as in space?