They altered the deal on Vader's helmet (jpeg & gif comparison) (self.StarWars) submitted 4 months ago by pldkn. In a previous Japanese trailer, we could see Darth's menacing pose as he turns to the camera - but mostly I saw his awkward neck situation. In a new Chinese trailer, they show the same shot again, but this time it's obviously edited. No more weird neck situation, much more sinister looking indeed.
Air parcels, in a horizontal air pressure gradient, flows in a direction to eliminate the pressure gradient. The force that causes air parcels to move as the consequence of an air pressure gradient is known as the pressure gradient force and always acts directly perpendicular to isobars and toward lowest pressure.
PG, as I understand it, the pressure gradient is essentially a comparison of blood pressure inside the heart on one side of a heart valve with the blood pressure on the outside of the valve. In the best of all possible worlds, the pressure should be the same on both side so there is no difference or gradient.