[solohan]

Thanks for elaborating on this. I guess the confusion also stems from the word "heat" which we usually associate with something that's warmer than some human day-to-day reference. Heat in the physical sense though just refers to the kinetic energy of a number of particles, which can be harvested (per the post above) provided there are differences in kinetic energy throughout space.

It's also interesting to play the "Follow the Energy" game to it's logical conclusion, namely that nearly all of the energy in the Universe (including that which you expend typing on your keyboard) originates from the gravitational potential created in the Big Bang (whatever that is, by the way). This begs the question; how was the entropy of the early Universe to low, that it could increase by such an enormous amount, to produce intelligent beings such as ourselves, typing things on a keyboard while we should be working?

It's really one of the most fundamental questions in cosmology, and one of the (many) reasons why I love physics.