8 minute read
Looking farther into the universe
James Webb Space Telescope Artist Conception
Ask a Professor How Does the Webb Telescope Enable Us to See Farther Into the History of the Universe?
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t this point, you may be wondering, “What’s the big deal with this James Webb Space Telescope?” It’s not often that astronomers dominate headlines across the world. However, it’s not every day that humanity successfully launches a space telescope as large or technologically advanced as the James Webb Space Telescope (JWST).
Astronomers have been looking forward to this moment for decades, with many of them having contributed large portions, if not the entirety, of their careers to this mission, so it is a momentous, once-in-alifetime achievement worthy of being celebrated worldwide. I know many astronomers around the planet were sitting in front of their computers, streaming the unveiling of the first JWST images with tears welling up in their eyes. I was certainly one of them.
For the general viewer, you might be wondering “Why is the telescope so special? Is it really all that different from the iconic Hubble Space Telescope?” Without going into details about the work involved in assembling the telescope and its instruments, let’s chat about at least one major scientific question the JWST can address and what makes it uniquely equipped to do so.
The telescope’s primary mirror is made of 18 hexagonalshaped segments and has an effective diameter (it’s not exactly round) of 6.5 meters. Compare that to the 2.4-meter mirror of the Hubble Space Telescope. For those who haven’t taken Introduction to Astronomy, the difference means that the JWST captures 7.3 times more light than the Hubble. More light collected means you can see fainter objects. The ability to see fainter objects translates to seeing more distant objects. Seeing more distant objects allows astronomers to peer farther back into the history of the universe.
In addition to being bigger, the JWST’s mirrors are made of beryllium and coated with a thin layer of gold. The beryllium provides a lightweight, yet strong structure with properties suitable to the low and shifting temperatures the telescope will encounter in space. The shiny gold coating makes the mirrors excellent at reflecting infrared light. That’s really important to understanding why the JWST is going to peer back in time to the formation of the very first stars and galaxies.
Due to the cosmic expansion of the universe set into motion by the Big Bang some 13.8 billion years ago, the wavelengths of light emitted from galaxies that are receding from us are “stretched.” The amount of stretching, or what is typically referred to as a redshift, increases with the distance to the object due to the very nature of the cosmic expansion. Most of us have experienced a similar phenomenon while parked at a railroad crossing as an oncoming train blows its horn. While the train might be getting louder as it approaches, we hear a higher pitch of the horn than if the train were parked on the track. As the train passes, we hear the opposite effect and the pitch gets lower. Sound is a wave, the wavelengths of which determine the pitch we hear. The motion of the train toward or away from us alters the wavelength of the sound, which translates directly to the shift in pitch we perceive with our ears. Shorter wavelengths (train approaching) lead to a higher pitch. Longer wavelengths (train receding) lead to a lower pitch. Light, also a wave, experiences this same phenomenon known as the Doppler Effect. If we replace our train in the example above with distant galaxies that all happen to be moving away from us as the universe expands, we can expect the wavelengths of the light emitted by these galaxies to be longer than if they were sitting still. Red light, having the longest wavelengths of light perceived by the human eye, lends its name to the increase in wavelength.
How much longer are the wavelengths of light coming from these first stars and galaxies? Imagine that the receding train is moving so fast that the pitch is shifted beyond our ear’s ability to perceive the sound. In a similar fashion, cosmic expansion redshifts the light from these galaxies to wavelengths that are beyond our eye’s ability to detect them. The effect of 13+ billion years of cosmic expansion is so dramatic that ultraviolet and visible light emitted by these first objects will be shifted into the infrared region of the spectrum and beyond the colors we perceive with our eyes.
The JWST, with its goldcoated mirror and suite of infrared sensitive instruments, is built to detect and decode the infrared light that has traveled to us from across much of the visible universe. The first images released were snapshots or a glancing view into space. They revealed that, once the JWST has more time to turn those glances into stares, it is going to provide a most excellent window to a time in the early universe that has previously been inaccessible to the world’s astronomers. When we peer through that window, we expect to find answers to questions related to the origins of elements and cosmic structures that determined the nature of the present-day universe. I feel like it is always a great time to be an astronomer, but the next few years are going to be special as the JWST challenges and expands our understanding of the universe on a regular basis.
— Jeff Bary is the Sweet Family Chair and an associate professor of physics and astronomy.
Research Black Infants Are Receiving Lower Quality Care. Why?
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n looking at neonatal intensive care units (NICUs), there can be inequities in care — especially with Black patients — finds Erika Miles ’92 Edwards. She researches the causes and consequences of the issue as director of data science for Vermont Oxford Network (VON), which is a nonprofit collaboration of more than 1,400 health care centers across the globe working together to improve neonatal care.
In America, Edwards reports, Black mothers are more than 50% likelier to deliver preterm babies than white mothers, and Black infants have a higher mortality rate than white newborns. “Our research shows that Black infants receive care at lower quality hospitals that have less resources, are less well staffed, and serve more patients,” she explains. “It’s also been shown that a majority of Black, Asian, and Hispanic infants receive care at hospitals where white infants do not.”
That lower-quality care creates a multigenerational problem: “The continued presence of structural racism and segregation has been shown to cause ‘weathering’ of a person’s genes,” Edwards notes. “That means prematurity can be passed down; so if a Black mom has a premature daughter, it’s more likely that her daughter in turn will have one.”
Edwards and her team at VON recently decided to dig deeper into more specific disparities in neonatal care, conducting a study of almost 170,000 infants at more than 700 hospitals. Their first finding revealed that health care providers frequently neglect to give pregnant women who are Black or Native American antenatal steroids, which encourage fetal lung development and maturity. A second finding showed that infants in those groups are also more likely to be admitted to the NICU suffering from hypothermia. “We don’t know exactly why these common standards of care are missing,” Edwards says. “But it likely comes back to the poorer quality and resources of the hospitals where these patients are admitted.”
Edwards and her team hope that by bringing findings like these to the attention of hospitals, staff members can improve “internal processes that include keeping newborns warm, or work with local providers to make sure that every mother receives the steroids,” she says.
“We want to have an impact by providing evidence-based, data-driven ways for them to achieve best practices,” says Edwards, who is also a University of Vermont research associate professor in the Department of Mathematics and Statistics and Department of Pediatrics.
Edwards designs webinars and other efforts to educate member NICUs on how to screen for social determinants of health, widely defined as the conditions in which people live, work, and play. If necessary, hospitals and clinics can then refer patients to social workers or pro bono lawyers who can help patients resolve disputes concerning housing, health benefits, and immigration.
The nonprofit’s grant program has provided seed money for innovative projects developed by member hospitals. These include nursing-led implicit bias training, peermentoring for moms going home with high-risk babies, and the purchasing of hospital-grade breast pumps to lend to patients who, for cultural or financial reasons, are reluctant or unable to breastfeed.
“Breast milk reduces the chances of all sorts of morbidities for a baby, but even so seemingly a small issue as this can become a matter of equity,” points out Edwards. “When your baby is in the hospital for 60 days and you need to work and provide child care for your other kids, you’re less likely to have the time to go back and forth to the hospital to breastfeed or to do it after you take the baby home.”
Neonatology has made “tremendous advances” during the decades that VON has been tracking infant mortalities, Edwards sums up. “Now we need to apply our efforts to the social aspects of medicine. From the time the baby arrives at the hospital through its stay there and continuing after its discharge, there’s a huge opportunity to consistently achieve better care and outcomes.” — JoAnn Greco
As a Colgate senior majoring in sociology and anthropology, Edwards read a New York Times article about NICUs. She was intrigued by the idea of “these places and who works at them and how they are organized,” she says. After deciding to pursue a career in health care management, she obtained degrees in public health and epidemiology. “I had a statistical bent and wanted to apply it to health.”
