Saturday Science looks at unusual experiments

The progress of physics requires the collaboration of both experimentalists and theorists; only the rare physicist, such as Enrico Fermi, has been successful at both lines of work.

Experimental physicists often exercise great ingenuity to arrange instrumented events that can either verify or falsify the clever ideas of their theoretical friends, who return the favor by laboring to fold the experimentalists’ most improbable findings into their theories.

At Washington University in St. Louis this semester, the Department of Physics and University College, both in Arts & Sciences, will describe a few of the experimentalists’ greatest successes. Four lectures on great physics experiments will be held at 10 a.m. on four consecutive Saturday mornings, March 10–31, in the Hughes Lecture Room, Room 201 in Crow Hall.

Presented by faculty members of the physics department and tailored for the general public, the lectures are free and open to the public.

The Saturday Science lectures have been organized since their inception 19 years ago by Michael Friedlander, PhD, professor of physics.

Friedlander, an experimentalist who studies cosmic rays and infrared and gamma-ray astronomy, has also written about pseudoscience and the conduct of science. He feels that scientists have an obligation to engage the public.

“As scientists,” he says, “we have an obligation to explain to the non-expert public what we are doing, what is exciting about our findings and where we think all of this may lead.

“In this way, we would hope that the public would gain some understanding of the methods of science, be willing to continue to support our efforts and will also not try to impose ideological restrictions to what we may study.

“History shows that none of this should be taken for granted,” he says.

The schedule

March 10, “The Discovery of Cosmic Rays and What They Are,” Martin Israel, PhD, professor of physics

This year, 2012, is the centennial of the discovery of cosmic rays – ionizing radiation bombarding the Earth from space. Israel will describe the early balloon observations by Victor Hess, who showed that the radiation was coming from space rather than originating on Earth.

TIGER, a WUSTL and NASA balloon-borne experiment to measure the elemental abundances of galactic cosmic rays.
Twenty years later, through his worldwide cosmic ray survey, WUSTL’s Arthur Holly Compton was able to show that the cosmic rays were not “rays” but rather were charged particles. Meanwhile, in studies of cosmic-ray particles in the laboratory, Carl Anderson found a positively charged electron — the theoretically-predicted “positron,” and in 1936 Hess and Anderson shared the Nobel Prize in physics.

March 17 “The LHC and the search for the Higgs,” Michael C. Ogilvie, PhD, professor of physics

An essential component of experiments that explore the internal structure of atomic nuclei are beams of high-speed nuclei. These are accelerated and made to collide. Debris from their collisions is examined and provide the clues being sought.

A simulation of the debris that would result if a collision at the collider in Geneva did produce a Higgs particle.
Ogilvie will describe experiments in progress at the Large Hadron Collider (LHC) in Geneva, where the existence of the predicted Higgs particle might be demonstrated.

March 24, “The Lamb Shift,” John Rigden, PhD, adjunct professor of physics

Rigden will describe the Lamb Shift, named for Willis Lamb who was awarded the Nobel Prize for experiments that explored the internal energy of the hydrogen atom.

March 31, “The Ingenious Experiments of Baron Roland von Eötvös,” Ramanath Cowsik, PhD, professor of physics and director of WUSTL’s McDonnell Center for the Space Sciences

The Eötvös experiment, planned by Baron Roland Eötvös in the early years of the 20th century, provides deep insights into the nature of gravity, and Einstein drew on these experimental observations as he formulated his General Theory of Gravitation.

For more information, contact Sarah Hedley at (314) 935-6276 or visit Click “Seminars/Events” and then “Saturday Lectures.”