The super collider would consist of an oval-shaped concrete tunnel 53 miles in circumference. Inside, twin counter-rotating beams of ionized atom fragments accelerated to nearly the speed of light would collide head-on with energies 20 times beyond what is available with the most powerful machine today.
Such collisions would help physicists search for the fundamental natural building blocks that are common to all matter, as well as the mysterious forces holding them together and governing their actions.
The high cost of the proposed super collider has prodded some scientists to wonder whether the machine might divert research grants from other, more practical scientific research or from other federal science projects, such as a proposed space station, a second-generation shuttle-like space plane and the "Star Wars" ballistic-missile defense system.
Congress, meanwhile, is debating whether the deficit-saddled federal budget can take on such a costly new project and, if it can, whether the new collider would be simply a one-experiment machine.
Collider proponents, including federal Energy Secretary John B. Herrington, note that President Reagan explicitly opposes cutting other research grants to pay for the super collider and in fact also has proposed doubling the National Science Foundation research budget over the next decade.
Herrington and William Graham, science adviser to President Reagan, are among those scheduled to attend a national conference Wednesday and Thursday in Denver to discuss the merits of the super collider.
Almost overlooked in the debate is exactly what the proposed super collider is designed to do over its 25-year lifetime.
"I think the main answer is, 'We don't know what it is going to do, except explore,' " said Edwin (Ned) Goldwasser, associate director of the SSC Central Design Group at the Lawrence Berkeley Laboratory.
At first, it would scout the very frontiers of high-energy physics, looking for new crumbs of subnuclear matter that are hinted at in complicated theories and mathematical models but undiscovered in real life. Such things can help to confirm a jigsaw-puzzle theory of atomic structure that could one day develop into a unified field theory, or "theory of everything." If such a concept exists, it could show how distinct phenomena--gravity, radioactivity, electromagnetism--are related.
No one contends that the proposed super collider would be able to answer all the mysteries confounding physicists. Scientists concede a more powerful tool will be needed in the next century, either by refitting the super collider or by building an entirely new one in some new way.