Cosmologist Andrew Lange Remembered

Colleagues remember Andrew Lange as a brilliant scientist with a large streak of generosity. A Caltech cosmologist known for his work on the general geometry of the early universe, Lange took his own life on 22 January. He was 53.

Lawrence Wade, who had worked with Lange since 1993, recalls how Lange would arrange for a postdoc to take all the equipment and the funding from a project to help him get established as a new faculty member. “I don’t know anybody else who is willing to give away a couple million dollars worth of hardware and funding to help one of his former students,” says Wade, a physicist at NASA’s Jet Propulsion Laboratory in Pasadena.

Lange was co-leader of an experiment that scored one of the bigger scientific coups in recent decades. In 2000, the Balloon Observations of Millimetric Extragalactic Radiation and Geophysics (BOOMERanG) reported the first high-definition measurements of the afterglow of the big bang, the so-called cosmic microwave background (CMB). The temperature of that ancient radiation varies randomly by about one part in 100,000 from point to point across the sky, and BOOMERanG was able to measure the distribution of sizes of the hot and cold spots before NASA launched its Wilkinson Microwave Anisotropy Probe (WMAP) to do much the same thing.

Reported in 2000, the BOOMERanG measurements nailed the general “geometry” of the universe and its age and, in concert with other measurements, gave the relative proportions of ordinary matter, mysterious dark matter, and space-stretching dark energy in the cosmos. WMAP mapped CMB across the entire sky and measured all of those things to higher precision, but some cosmologists say that BOOMERanG stole WMAP’s thunder. “WMAP only confirmed these discoveries,” Wade says.

“Some people thought he would have been a candidate for a Nobel Prize,” says John Mather, a cosmologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who himself won a Nobel Prize for measuring the spectrum of the microwaves in CMB. Lange was manifestly gifted, Mather says. Lange worked at Goddard one summer as an undergraduate at Princeton University and “he stayed in my basement,” Mather says. During his free time, Mather recalls, Lange entertained himself reading Gravitation by Misner, Thorne, and Wheeler, a 1000-page tome on general relativity. “He was really an amazing talent already.”

John Ruhl, a cosmologist at Case Western Reserve University in Cleveland, Ohio, recalls that Lange invited him to work on BOOMERanG. “He kind of gave me my big break,” Ruhl says. "The idea that he’s gone now is a hard hit.” Lange is survived by his ex-wife, Frances Arnold, a Caltech biochemist, along with a stepson and two sons.