Dartmouth’s Marcelo Gleiser Questions the Limits of Knowledge


Dartmouth physicist-philosopher Marcelo Gleiser wonders if we can ever really know all there is to know. In this video, he probes the depths of that question.

To some, the history of science seems an inexorable march toward the point that one day we will know all there is to know—what Gleiser calls the end of knowledge. Part of this progression has been the pursuit of a unified theory of nature, a “theory of everything” that Gleiser regards as a mirage that grows more distant with each step toward it.

Much of what we know of the world depends on instruments, he notes: “Without our telescopes, microscopes and particle detectors, our vision of reality would be much more limited. Technology opens new windows to the world. Still, as with our eyes, these instruments have limits. And thus, so does our knowledge of reality acquired through their use.“

Marcelo Gleiser is the Appleton Professor of Natural Philosophy and a professor of physics and astronomy. (photo by Joe Mehling ’69)

While Gleiser acknowledges that we do need better tools, each new tool of discovery we put to use both teaches us more about the world and adds to our sense of how much more there is that we do not know. “There will always be new challenges, questions that our research and inventiveness will not be able to anticipate,” Gleiser tells us.

To paraphrase former U.S. Secretary of Defense Donald Rumsfeld, ”We do not know what we do not know.“


Professor Marcelo Gleiser Contemplates a Question of Cosmic Significance

Joseph Blumberg