The debate over President Reagan's Strategic Defense Initiative (SDI) is increasingly becoming a ``brain quest'' -- with each side claiming it has the most support within America's scientific community. The tools being used in this process include open letters and petitions being circulated at research laboratories and universities across the country, polls of scientists on their attitudes toward the program, and stacks of reports.
The latest report was unveiled yesterday by the Union of Concerned Scientists (UCS), a leading critic of SDI. In it, the group says, is information that ``exposes the inherent technical and strategic flaws'' in the program. At the same time, organizers of two separate efforts by scientists to limit ``star wars'' research announced they were joining with the union in a major public education campaign.
The newly issued report concludes that technical complications -- such as satellite vulnerability and the design of computer software for a strategic defense system -- have become more, not less, daunting as research has progressed and that the program should be shelved.
Critics counter that such conclusions are ``premature'' and are motivated more by political considerations. Much of the information about SDI research is classified, these sources say, so it would be almost impossible for most scientists to draw informed conclusions.
Indeed, even many scientists who refuse to take sides in the debate point out that too little is known about the technologies involved to satisfy the questions that remain both in the minds of the public and the technical specialists.
``The real debate among scientists is over the level of spending and what the funds are going to be used for,'' says Philip Schewe, a particle physicist and writer with the American Institute of Physics. An important distinction must be drawn, he says, between doing laboratory research on a weapon system and the actual decision to build and deploy it.
``As a deployable weapons system, I don't think most physicists want it,'' Dr. Schewe says. ``But that doesn't mean that you don't do the laboratory work.''
This view is supported, to a degree, by a recent survey conducted by an independent research firm on behalf of UCS. The survey selected 549 physicists at random from the 1985 American Physical Society directory. It showed that physicists opposed deployment of SDI by nearly 2 to 1, but that they favored basic laboratory research by a greater margin.
Partly because of such surveys, the scientific community has become the focus for intense political debate.
An anti-SDI petition first surfaced last year on several university campuses and was later merged into one. Scientists who have signed the letter pledge not to accept or solicit funds related to SDI research. Organizers say nearly 7,000 faculty members and graduate students have signed, including nearly 60 percent of the combined faculties of 20 of the nation's top-ranked university physics departments.
``We feel that if we can slow the growth of the SDI program, it will give Congress time to reassess it, and the program will be skuttled,'' says Dr. John Kogut, a physics professor at the University of Illinois and one of the architects of the petition drive.
Another petition is circulating at government and industrial laboratories, many of which are deeply involved in SDI research. According to organizers, that petition has now more than 2,000 signatures of scientists and engineers currently or formerly associated with the facilities and include five Nobel prize winners.
This group is not asking that SDI research be halted, but that it be kept at a realistic level. In an open letter to Congress last June, the group warned that uncontrolled expansion of the program could escalate the arms race.
Advocates of SDI dismiss the petition drives, saying they represent a minority view within the scientific community. The scientists ``opposed to SDI will be left behind,'' says Dr. Kim Holmes, national-security analyst for the conservative Heritage Foundation, a Washington think tank. ``There's a lot of progress being made, and that's going to convince those people already working on projects . . . that strategic defense is feasible.''
Pro-SDI forces have formed their own group of about 100 scientists who publicly support the program, called the Science and Engineering Committee for a Secure World. A spokesman for the group contends that the vast majority of scientists are ``either pro or neutral'' on the subject of SDI.
About the only point of agreement among all sides is that the issue of strategic defense has become hopelessly mired in politics. ``SDI really can't be discussed anymore as a scientific issue,'' says Martin Hoffert, a professor at New York University who favors continued research on SDI. ``It's become an issue of how liberal you are or how conservative you are.''