Nick writes...
"Here Dawn and Brandy "argue" over the statement that the curl of a conservative vector field (such as gravity) is equal to 0." (Note: at the top, it should read phi = - m M G / r, not del(phi). My fault.)
"Miz Sylver (Dawn) and Wolf (Brandy) are both MITstudents. Miz Sylver is an active rpg player and creator of a digital comic strip, while Wolf, a linux-user, sailor, and longtime Star Trek fan, has just joined the crew of the MIT tow tank, a lab specializing in flow visualization and robotic fish."