Excerpt from my commentary, "I’ve been waiting for this moment for decades,”Reflex (Switzerland) No. 4, 54–55 (April 2008)  Welcoming the LHC [3:12m]:


Nature’s Greatest Puzzles,  Podcast of my keynote lecture at the 2004 SLAC Summer Institute   [66:01m]:
Click here for slides and video. Companion paper from the Proceedings.


Podcast of my keynote lecture at the May 22, 2006 Fermilab Symposium on the Nature of Science, [48:28m]:
Click here for slides.

Abstract: Science is one source and symbol for an imaginative, disciplined mind. In addition to giving us basic information we need to make sense of the natural world, the sciences teach us to identify and scrutinize our assumptions, to hone our powers of analysis, and to expand our capacity for synthesis. They impart great lessons for any vocation: to link cause with effect, to search for relevant evidence, and to seek the truth without self-deception.

As a method for exploring—for finding things out—science lives by its disdain for Authority and its reliance on experimentation and observation. The seventeenth-century gentlemen who founded the Royal Society of London took as their motto Nullius in verba—Don’t take anyone’s word for it! Scientists are human. They have limited powers, they make mistakes, they have incomplete knowledge, they may be too bold or too cautious in interpreting their findings. Science is a system by which imperfect beings can test and refine their understanding of the world.

Like the practice of science, the study of science must be more than acquiring a collection of facts. An awareness of how scientists think and how science is done helps us realize its limitations. Scientists are accustomed to dealing with doubt and uncertainty. Good scientific advice may be frustratingly conditional: sometimes scientists don’t know enough to give a straight answer; sometimes Nature just can’t be pinned down. And there are some issues—like moral choices—that science by itself can only inform, not resolve.

Scientific exploration is open-ended: today’s facts are merely precise statements of what scientists understand at this particular time, not eternal truths. Science is organic, tentative; like life itself, science is a becoming, a great adventure of the human mind and spirit.


The Coming Revolutions in Particle Physics, podcast of my Fermilab Auditorium Lecture, January 18, 2008 [66:40m]:
Click for slides. Companion article in the February 2008 Scientific American

Abstract: Next summer, the Large Hadron Collider at CERN will advance the experimental frontier of particle physics to the heart of the Fermi scale, reaching energies around one trillion electron volts for collisions among the basic constituents of matter. We do not know what the new wave of exploration will find, but the discoveries we make and the new puzzles we encounter are certain to change the face of particle physics and echo through neighboring sciences.

In this new world, we confidently expect to learn what distinguishes electromagnetism from the weak interactions, with profound implications for our conception of the everyday world. We will gain a new understanding of simple and profound questions: Why are there atoms? Why chemistry? What makes stable structures possible? A pivotal step will be the search for the Higgs boson and the elaboration of its properties. But there may be much more: we have hints of other new phenomena, including some that may clarify why gravity is so much weaker than the other fundamental forces. We also have reason to believe that candidates for the dark matter of the Universe could be lurking on the Fermi scale.

Beyond the Fermi scale lies the prospect of other new insights: into the different forms of matter, the unity of quarks and leptons, and the nature of spacetime. The questions in play all seem linked to one another—and to the relationship of the weak and electromagnetic interactions. Exploring the Fermi scale will help us to define the questions more acutely, and may set us on the road to answering them.