I'm getting worried, again, about the future of "pure science," which seeks knowledge for its own sake rather than for practical applications, like thermonuclear bombs and erectile-dysfunction treatments. I was also worried in 1996, when I argued in The End of Science that pure science might be entering an era of diminishing returns.

One source of my current concern is a freshman composition course I'm teaching at Stevens Institute of Technology. Last week, my students read an old Michio Kaku piece, which explains-celebrates dark matter, super strings, cosmic strings (remember them?), inflation and other physics phantasms. (Kaku's essay is one of many fun, science-y selections in our textbook, A World of Ideas: Essential Readings for College Writers, edited by Lee Jacobus.)

After my students and I chewed over Kaku's style, we switched to substance. I asked if taxpayers should pay for research on particle physics and cosmology when the results will probably have no practical payoff. Out of 25 students, 24 said no, and the lone hold-out was ambivalent; he would support the research if the economy were stronger.*

The students didn't want to fork over a slice of their future earnings for research that would not provide a "return on investment," as one put it. Knowledge of what the universe is made of, where it came from and where it's headed didn't count as an adequate "return." "The government shouldn't pay for things that don't directly benefit us," one person said, as others nodded. "Let some billionaire support that stuff if he wants to," someone else chimed in.

Around the same time, I was checking out responses to a question that science-book agent John Brockman just posted Edge.org: "What should we be worried about?" Brockman has been posing questions like this to his stable of professional eggheads, or Edgeheads, annually since 1998. Reading over responses to Brockman's question, I was struck by how many Edgeheads are fretting over the future of particle physics in particular and pure science in general. Here are edited excerpts from Edge.org:

Lisa Randall, physicist: "I worry that people will gradually stop the major long-term investments in research that are essential if we are to answer difficult (and often quite abstract) scientific questions… The applications are not obvious so there has to be an underlying belief that finding the answers to deep and significant questions about how the universe evolved, how we evolved, what we are made of, what space is made of, and how things work is important. The ability to find answers to these questions is one of the characteristics that makes human beings unique and gives meaning to our lives. Giving this up for short-term ends would ultimately be a tragedy. In my specific field of particle physics, everyone is worried. I don't say that lightly. I've been to two conferences within the last week where the future was a major topic of discussion and I'm at another one where it's on the agenda. Many ideas are presented but my colleagues and I certainly worry whether experiments will happen."

Peter Woit, mathematical physicist: "During the 20th century the search for a theory of how the physical world works at its most fundamental level went from one success to another… After centuries of great progress, moving towards ever-deeper understanding of the universe we live in, we may be entering a new kind of era. Will intellectual progress become just a memory, with an important aspect of human civilization increasingly characterized by an unfamiliar and disturbing stasis? This unfortunately seems to becoming something worth worrying about."

Keith Devlin, mathematician: "Are we about to see advances in mathematics come to an end? Until last year, I would have said no. Now I am not so sure. Given the degree to which the advances in science, engineering, technology, and medicine that created our modern world have all depended on advances in mathematics, if advances in mathematics were to come to an end, then it's hard to see anything ahead for society other than stagnation, if not decline."

Steve Giddings, physicist: "[W]e face a crisis within the deepest foundations of physics. The only way out seems to involve profound revision of fundamental physical principles… The current problems at the foundations link to multiple big questions—and I fear it will be no small feat to resolve them."

Lawrence Krauss, physicist: "There may be… new limits looming on our ultimate ability to probe nature—made manifest because of the truly remarkable successes of physical theory and experiment in the past 50 years—due to the accident of the circumstances in which we find ourselves living, which could, at least in principle, change the way fundamental science may progress in the future… Perhaps then, at the extremes of scale empirical science will reach its limits, and we will be reduced to arguing about what is plausible, rather than testing our ideas… I should conclude by stressing I do not believe that any of these possible limits will lead to the end of science itself, or even the end of physics, as some naysayers have proposed in the past. There are enough remarkable and perplexing aspects of the universe we can measure to keep us going for a very long time."

To this naysayer, Krauss sounds like a man whistling past the graveyard.

I was mulling over the Edgehead comments when someone sent me a link to a Nature essay that was like the rotten cherry on a sundae of gloom. The title, "Scientific genius is extinct," is misleading. Dean Keith Simonton, a psychologist who studies scientific creativity, doesn't claim that modern scientists aren't as smart as their predecessors. He suggests, rather, that revolutionary discoveries are less likely today because scientists have already discovered so much.

"Our theories and instruments now probe the earliest seconds and farthest reaches of the universe," he writes, "and we can investigate the tiniest of life forms and the shortest-lived of subatomic particles." Hence scientists will produce no more "momentous leaps," ideas that are truly surprising rather than "just extensions of already-established, domain-specific expertise."

"Future advances are likely to build on what is already known rather than alter the foundations of knowledge," Simonton adds. "One of the biggest recent scientific accomplishments is the discovery of the Higgs boson—the existence of which was predicted decades ago."

Compare the concerns of Simonton and the Edgeheads to what I wrote 17 years ago in The End of Science. I argued that "given how far science has already come, and given the physical, social and cognitive limits constraining further research, [pure] science is unlikely to make any significant additions to the knowledge it has already generated. There will be no more great revelations in the future comparable to those bestowed upon us by Darwin or Einstein or Watson and Crick."

Edgeheads and other pessimists, welcome to the end-of-science bandwagon.

*Clarification/confession: After polling my freshman comp class, I asked 40 students in two other classes whether they thought particle physics and cosmology should be supported by tax dollars, and about 1/3 said yes. Perhaps students in my freshman comp class were more hostile to theoretical physics because they had to read Michio Kaku's essay--plus two other assigned pieces, my recent critique of his gee-whizzy proselytizing for particle physics and our $1,000 bet on the prospects for a unified theory.