Los Alamos Rotary Hears Talk By Astrophysicist Dr. Rick Wallace On ‘The James Webb Space

Astrophysicist Rick Wallace recently gave a presentation about the deep space images from the James Webb Space Telescope to the Rotary Club. Here he assures his audience that there will only be a ‘tiny bit of physics’. Photo by Linda Hull

By LINDA HULL
Vice President
Rotary Club of Los Alamos 

Promising his presentation would only include “tiny bit of physics”, Dr. Rick Wallace, retired Los Alamos National Laboratory astronomer and astrophysicist, spoke Aug. 2 at the Rotary Club of Los Alamos about “The James Webb Space Telescope, First Images 2022”.

With PowerPoint slides that featured James Webb Space Telescope (JWST) images of the Cosmic Cliffs of the Carina Nebula, the M74 Classic Spiral Galaxy, the Southern Ring nebula, and Stephan’s Quintet of galaxies, which captures the collision of two galaxies, Wallace began by explaining that James Webb, after whom the satellite is named, was NASA’s administrator during the Mercury, Gemini, and Apollo programs in the 1960s.  

The JWST is comprised of two infrared cameras, meaning the images taken indicate the degree of heat radiated by an object.  Unlike its predecessor, the Hubble telescope, the JWST has significantly higher resolution and is able to see through clouds of dust and gas.  Its mirrors span 21 feet, compared to the Hubble’s 8, “giving the JWST about seven times more collecting area.”  Its field of view “covers more than roughly 15 times the area” of the Hubble.

In an orbit well past the moon, the JWST is inaccessible to repairs or adjustments from space shuttle crews unlike the Hubble, which was serviced five times.  

In describing the means in which images are captured by the JWST’s infrared cameras, Wallace delved into the wavelength sensitivity of various telescopes, as well as basic spectroscopy.  This included the emission and absorption spectra of assorted chemical elements and the effects of density, pressure, and wavelength on spectra.  

Wallace also briefly mentioned the role of the Doppler Effect in light wave spectra to identify galaxies in the very early stages of the formation of the universe and to showcase the composition of galaxies.  Gravitational lensing, another technical application, reveals amplified images of distant galaxies. 

As American astronomer Edwin Hubble proved in the 1920s, galaxies exist beyond our own Milky Way, and the universe is expanding and accelerating. In just one JSWT image thousands of galaxies have already been detected. The most recent images, those of the GLASS-z13 galaxy, date back 13.5 billion light years, only 300 million light years after the Big Bang. (A light year is the distance light travels in one Earth year. One light year is about six trillion miles or 6,000,000,000,000 miles! Yes, 12 zeros.)

In closing, Wallace quoted from a recent commentary by Tony Barboza writing for the LA Times: “For some, the takeaway from these new glimpses into deep space may be that Earth is small and insignificant. That the more clearly we see the universe, in its rich vastness, the more our planet seems like an infinitesimal drop in a cosmic ocean.

But to me, our growing understanding of the universe only reinforces the fact that Earth is our only home.  It is still the only planet we know of that sustains life. It is protected from a thin and delicate environment.  It is under threat from climate change and other human-caused threats. It’s still singular, precious and worth fighting for.”

Dr. Wallace has a Ph.D. in Astronomy and Astrophysics from the University of California Santa Cruz, home of the Lick Observatory, with a concentration of studies in numerical calculations of stellar explosions (novae, supernovae, X-ray bursts) and nuclear fusion. He worked at LANL for 30 years in physics simulations, security of Russian nuclear material, technical management, and international safeguards. 

Wallace’s hobbies are nature and wildlife photography and developing presentations for the planetarium at the Pajarito Environmental Education Center (PEEC).  

The Rotary Club of Los Alamos, through its Club Foundation, is a 501(c)3 non-profit and one of over 34,000 clubs worldwide. Rotary, which now has 1.5 million members, was founded in 1905; the local Club was chartered in 1966. Rotary areas of focus include promoting peace; fighting disease, particularly polio; providing clean water, sanitation, and hygiene; supporting education; saving and enhancing the lives of mothers and children; growing economies; and protecting the environment.

The Rotary Club of Los Alamos meets in person 12-1 p.m. Tuesdays, in the Community Room at Cottonwood on the Greens at the golf course. A Zoom option is available by contacting Rotary Club Vice President Linda Hull at 505.662.7950. Hull also is happy to provide information about the Club and its humanitarian service.