A Robert Irwin groupie poses with the artist after his talk last night at the Parma Payne Goodall Alumni Center at SDSU.   She's really an art professor at SDSU, but there was a line of fans waiting to get their pictures taken with Irwin.         Poster for Ferus Gallery's The Studs exhibition, Los Angeles, 1964. The photo on the right is  Billy Al Bengston,    Allen Lynch, Robert Irwin, Craig Kauffman, John Altoon, Ed Kienholz, and Ed Moses, Los Angeles, 1958     Some things never change. At 85, Robert Irwin is still a stud (see photo above).     Image: East of Borneo       Untitled,  1961     Irwin's talk focused on his artistic journey of reduction, beginning with his abstract expressionist phase.    The end product would be to get to the point of "pure energy".     Image: Christie's          Untitled,  1964     The reduction progresses.     Image: Christie's          Untitled,  1966. O il, dots on canvas with bowed wood frame       Now...