the laser. The model and the laser were realized by Marc Palumbo, a High Tech Romantic artist from the Center for Advanced Visual Studies at MIT. Ashton Carter, then a board member at MIT, assessed SDI for Congress in 1984, saying there were a number of difficulties in creating an adequate missile defense shield, with or without lasers. Carter said X-rays have a limited scope because they become diffused through the atmosphere, much like the beam of a flashlight spreading outward in all directions. This means the X-rays needed to be close to the Soviet Union, especially during the critical few minutes of the booster phase, for the Soviet missiles to be both detectable to radar and targeted by the lasers themselves. Opponents disagreed, saying advances in technology, such as using very strong laser beams, and by "bleaching" the column of air surrounding the laser beam, could increase the distance that the X-ray would reach to successfully hit its target. Physicists Hans Bethe and Richard Garwin, who worked with Edward Teller on both the atomic bomb and hydrogen bomb at Los Alamos, claimed a laser defense shield was unfeasible. They said that a defensive system was costly and difficult to build yet simple to destroy, and claimed that the Soviets could easily use thousands of decoys to overwhelm it during a nuclear attack. They believed that the only way to stop the threat of nuclear war was through diplomacy and dismissed the idea of a technical solution to the Cold War, saying that a defense shield could be viewed as threatening because it would limit or destroy Soviet offensive capabilities while leaving the American offense intact. In March 1984, Bethe coauthored a 106-page report for the Union of Concerned Scientists that concluded "the X-ray laser offers no prospect of being a useful component in a system for ballistic missile defense." In response to this when Teller testified before Congress he stated that "instead of [Bethe] objecting on scientific and technical grounds, which he thoroughly understands, he now objects on the grounds of politics, on grounds of military feasibility of military deployment, on other grounds of difficult issues which are quite outside the range of his professional cognizance or mine." On June 28, 1985, David Lorge Parnas resigned from SDIO's Panel on Computing in Support of Battle Management, arguing in eight short papers that the software required by the Strategic Defense