Audience members filed out of Sanders Theatre shaking their heads after yesterday's third and last lecture by renowned theoretical physicist Stephen Hawking.

"I got completely lost," said Rabbi Benjamin E. Scolnic who had traveled from Connecticut to hear the lecture.

Scolnic, along with his nine-year-old son and roughly 700 others, had just heard Hawking present his theories on cosmology and the shape of the universe.

After his first lecture, which was meant for the general public, Hawking concentrated on the more specific, targeting a knowledgeable audience in the second and third lectures.

Hawking first articulated the conundrum of cosmology, explaining that it is merely a "pseudo-science" because it has no predictive power. Based on current observations, cosmology uses equations to extrapolate back into the past.

Essentially, said Hawking, "It is as it is now because it was as it was then," leaving the past ungrounded in fact.

In response, Hawking utilized complex concepts, such as M-theory, eleven-dimensional gravity, boundary conditions and the Anthropic Principle to set up his understanding of the universe's shape.

Hawking proposed that the no-boundary principle--which states that the universe has no boundaries--works symbiotically with the Anthropic Principle to solve cosmological questions.

The Anthropic Principle states that 'if the universe weren't suitable for life, we would not ask why in the first place." Although many physicists dismiss the Anthropic Principle as groundless, Hawking defended it as necessary to understand that models of the universe are shaped by our human limitations.

Hawking explained that the principle, along with the no-boundary condition, narrows the multiple cosmological scenarios, down to a model of the universe like our own.

Freed from previous constraints, Hawking used advanced mathematical modeling and four-dimensional Euclidian spheres to demonstrate that the universe likely is in the form of a squashed sphere.

An anomalous "singularity," which Hawking drew to resemble a protruding belly-button, sticks out on the southern pole of the universe. Hawking said that it could be detected through astronomical observations.

As the lecture proceeded, it became even more theoretical, leaving many people, like Robert G. Bieshaar, a visitor from Germany, groping for answers.

But much of the crowd, the majority of which had little physics background, remained in awe of the magnetic Hawking.

"This can't be ignored," said retired firefighter Joseph M. Clink.

Audience members with a stronger background in the field further lauded Hawking.

"He has some of the seminal ideas in the nature of quantum mechanics and relativity," said Raoul Bott, Graustein professor of mathematics and former master of Dunster House.

Indeed, Hawking drew a crowd because of his fame. Bound to a wheelchair for his adult life, he has overcome his handicap to become the world's foremost expert on theoretical physics. Each of his lectures took 30 hours to prepare, and he still managed to write another paper during his one-week stay at Harvard.

Hawking has worked to publicize his esoteric field with user-friendly books like A Brief History of Time.

"He's the Albert Einstein of popular culture," said Emily S. Lin '02.