On: Brazillian businessman built a giant perpetual eng...

[ratww]

At the end of the page it seems the university offered some unrequested advice on the second law of thermodynamics.

It was dismissed on the grounds of the sun being "eternal" and gravity being an energy that can be "harvested" in the same way solar energy can.

[vasco → ratww]

They are right in the sense that you can count on the earth to pull your stuff down for free, they just forgot they have to put it back up themselves.

[drran → vasco]

Earth rotation and Moon orbiting can do a massive amount of work (see tide waves), but energy density is very low.