His speech was slow, his voice computerized--and there was not an empty seat in Sanders Theatre.

Stephen W. Hawking, a physicist compared in stature to Isaac Newton, spoke last night about the "shape of time" 84 years after Albert Einstein advanced his theory of general relativity.

But many attendees said Hawking's sheer presence left more of an impression than the scientific intricacies he described.

For two minutes, during sustained applause, an elevator inched Hawking, seated in a wheelchair, to the level of the stage.

The theater then went dark, except for a small spotlight focused on Hawking's slight frame.

Stars, the subject of Hawking's life work, appeared on a screen behind him.

The Lucasian professor of mathematics at Cambridge University then launched into an hour-long lecture, touching on the nature of time, "p-dimensional superstrings," and the search for a unified "theory of everything."

Hawking noted how physicists have realized that time is not as constant and once believed, but is instead highly variable, with eddies that can move forward, backward, and even repeat themselves.

The physics of the speech eluded some listeners at times.

"It was very interesting, although I certainly didn't understand most of what he said," Dan Krockmalnic '02 said.

Still, Hawking's wit and delivery elicited laughter and applause from the audience.

Hawking showed flashes of biting British humor throughout the speech, frequently breaking out into a wide grin after telling jokes.

When Hawking mentioned a theory predicting an infinite number of universes with an infinite number of outcomes, he quipped that "theoretically, there exists an alternate universe where the Redskins won the Super Bowl, although its probability is very low."

Hawking's 1969 paper proving that time had a beginning won second prize in the Gravitational Research Foundation's annual competition, "winning me the princely sum of $300," said Hawking, as a cartoon depicting a number '2' trophy appeared on the screen behind him.

"I don't know who won first prize, but I hope his paper turned out to be wrong," Hawking quipped.

Hawking communicates with the aid of a computer and speech synthesizer attached to his wheelchair, which requires that he select words one by one from a list on the computer. According to Hawking, this allows him to speak as fast as fifteen words a minute.

Hawking was diagnosed with Lou Gehrig's disease, a degenerative motor neuron disease, at the age of 21 and has spent the last 14 years confined to a wheelchair. He currently has motion only in two fingers of his left hand.

An aide said Hawking spent about 40 hours composing his lecture, which took only an hour to deliver.

Hawking once admitted that his widespread fame among the general public may, in part, have something to do with his disability.

"I'm sure my disability has a bearing on why I'm well known," Hawking has said in an interview with the BBC. "People are fascinated by the contrast between my very limited physical powers, and the vast nature of the universe I deal with."

Listeners found Hawking's voice, as synthesized by his on-board computer, a bit hard to understand at first.

"I had a little trouble, because his inflexion was a bit odd," said David A. Crych '03, "but you get used to it after a while."

Hawking quipped that his synthesized voice has been described as having " a Scandinavian American accent."

In addition to his computer-controlled intonation, the restraints of Hawking's speech system required a pause of several minutes after a student asked a question, so that Hawking could formulate a reply.

The Loeb Lectures, which brought Hawking to Harvard, continue tonight and next Tuesday. The Physics Department brings several speakers to campus every year, each of which typically gives three to five separate talks.

After Hawking first gave a Loeb lecture at Harvard in 1984, he decided to make theoretical physics accessible to the layperson through his now famous book, A Brief History of Time.

Tickets to the speech series were distributed free of charge on September 16 at the Harvard Box Office.

All 3,345 of them were given out in under an hour--about one ticket every second.

In recent memory, no Loeb lecture has been popular enough to require that the Physics Department issue tickets, said Professor of Physics Andrew Strominger '77.

"These lectures are not ordinarily attended by the general public, although the public is always welcome," Strominger said.

Kelly V. Brogan, an MIT senior, was the first person in line to buy a ticket on the morning of September 16. She said she started waiting at 9 a.m., though the box office didn't open until noon.

"It's a phenomenal opportunity to hear a man of his stature speak," Brogan explained.

Miranda Yousef '98, a ticket agent at the box office, said at one point the line snaked from one end of the Holyoke Arcade to the other, and then back again.