[In the excerpt below, Suplee contends that while Black Holes and Baby Universes is interesting, it adds nothing new to Hawking's theories in A Brief History of Time.]

If asked to list the cruelest disappointments of modern life, most folks will cite their first date, latest paycheck and page 134 of Stephen Hawking's A Brief History of Time.

That is the point at which the fabled Cambridge physicist is just about to reveal his theory on the shape and fate of the whole confounded cosmos—and then notes that, of course, it can only be understood in terms of "imaginary time" whose values produce negative numbers when squared. Make that simple adjustment and presto: "The distinction between time and space disappears completely." So, alas, does comprehension.

Even brand-name brains boggle at imaginary time, and many a reader reluctantly abandoned the book in intellectual despair. But now, five years later, a new Hawking volume has arrived. And naturally expectations are high that Black Holes and Baby Universes and Other Essays will fill the very considerable explanatory gaps left by Brief History.

But no. The new book is merely a collection of Hawking's various speeches and writings (including a Scientific American article 16 years old!) that have never been published together—for the excellent reason that there is no particular need to do so. The 14 short pieces range from reminiscences about his childhood to athoroughly conventional plea for greater public understanding of science to various lectures on astrophysics to the transcript of a BBC interview broadcast last Christmas.

The autobiographical material is pretty familiar. Born in 1942 to a somewhat eccentric research physician and his wife, Hawking was the eldest of four children. He went to such a progressive school that he was 8 years old before he learned to read. He was fascinated with toy trains, and eventually chose to study physics because it was the "most fundamental science" even though it was demonstrably "the most boring subject at school because it was so easy and obvious. Chemistry was much more fun because unexpected things, like explosions, kept happening."

At 17 he went to Oxford, where he detected the first premonitory signs of Lou Gehrig's disease, a progressive motor-nerve disorder that would eventually confine him to a wheelchair and require 24-hour nursing care. After a period of depression ("I took to listening to Wagner, but reports … that I drank heavily are an exaggeration"), his engagement to "a girl called Jane Wilde" "gave me something to live for." Apparently so: He finished his doctorate at Cambridge, fathered three children and became one of the most distinguished theoreticians in modern memory. This despite a tracheostomy that left him able to speak only through a computer voice synthesizer. Hawking has never been interested in revealing personal details of his illness or how he coped with it, and continues that reticence here.

He wrote the phenomenally successful Brief History in part to pay his daughter's school bills, chose Bantam as the publisher because "I wanted it to be the sort of book that would sell in airport book stalls," and vigorously disputes the idea that "Bantam shamefully exploited my illness and that I co-operated with this by allowing my picture to appear on the cover. In fact, under my contract I had no control over the cover."

In the BBC interview, he reveals a keen fondness for music, and a surprisingly eclectic taste. Asked what records he would want if marooned on a desert island, he cites Poulenc's "Gloria," Brahms' Violin Concerto, Beethoven's String Quartet (Op. 132), Act One of "The Valkyrie," The Beatles' "Please Please Me" and Edith Piaf singing "Je Ne Regrette Rien" among others. The last, he writes, "just about sums up my life."

The eight scientific pieces, though interesting, are largely a restatement of material treated at more commodious length in Brief History. Seven of them are texts of speeches that contain a great deal of overlap, including repetition of some of the same jokes. People curious about Hawking's mind-stretching insights into cosmology will be better served by returning to the original 1988 volume, which still offers the biggest cerebral bang for the buck.