Particle cosmologist Luna Zagorac explores how underdog experiments can punch above their weight through her experiences in astronomy.
My career as an astronomer began – unhelpfully – in one of the cloudiest cities in the United States.
When the clouds did occasionally part, we did have a telescope at Colgate University in Hamilton, NY, but it was a decades-old 16-inch instrument at the aptly named Foggy Bottom Observatory (FBO).
But what FBO lacked in technological superiority it made up for by punching above its weight, and by teaching me that when it comes to data, big isn’t necessarily best.
One of the key skills any astrophysicist develops is thinking in scales. Numbers like one, two, and five cease to matter, our desire for precision superseded by our need to understand huge numbers.
One day, you’re calculating precise speeds of balls rolling down ramps; the next, you’re waving your hands in the air with a quasi-religious chant of “to first order!” and claiming that pi squared is basically 10.
After all, when dealing with numbers that can only be expressed as exponentials, the idea of “big” and “small” shifts rapidly in the direction of “huge” and “slightly less huge.” In the words of one of my favorite physics teachers, Professor Jonathan Levine of Colgate University, “What’s a factor of 10 amongst friends?”
This bias towards the large is particularly nurtured in cosmology. We deal with masses more suited to being expressed in huge multiples of solar mass than kilograms; we consider fast-varying if they change over a million years rather than a billion years; we talk about distances that make a light-year seem like a short jaunt.
It’s not a surprise, then, that the bias of astronomical instrumentation trends the same way. In the 1600s, Galileo first spied four of Jupiter’s moons through a telescope with an aperture of 15 mm — about 0.6 inches.
Almost 100 years ago, Hubble’s discovery that the universe is expanding came courtesy of the 100-inch telescope at Mount Wilson Observatory. Today, we are aiming for even more precision, which often translates into bigger and better telescopes, including those launched into space.
It’s expensive, expansive, and exciting. It’s also oversubscribed as never before: only one out of every 10 observing proposals for the James Webb Space Telescope (JWST) was chosen to be carried out.
While each of these observatories is gargantuan, their number is limited, as is the number of operators any instrument can support at a given time. At the same time, the number of astronomers is booming: just in the United States, the number of undergraduates enrolled in astronomy degrees has risen by over 300 percent in two decades, and almost half of astronomy bachelors enroll in a related graduate degree.
Sheer numbers dictate that not all of these new astronomers will get time on one of the larger telescopes. It will be worse for those attending small or under-resourced institutions. Outside of the US and other affluent countries with space programs, access is likely to be even sparser. This feeds into existing equity issues in astrophysics and limits the scope of ideas being tested with observations.
As an undergrad at cloudy Colgate University, I did not have access to the most cutting-edge new telescopes. Instead, I learned to take data with our in-house telescope, which is just slightly larger than I am. While the aperture of that telescope is small, its contributions to astronomy are in no way doomed to be the same. In fact, the university is a hub of research in Active Galactic Nuclei (AGN), the superheated glowing gas falling into a black hole. These phenomena emit so much light that they can be easily spotted with that 16-inch telescope in rural New York state when the clouds part.
I happened to be operating the telescope at just the right time: in the summer of 2014, when one of the AGN on our list of targets — a blazar called 3C454.3—was going through a flare. A flare is a period of increased brightness for an AGN which can last for months at a time, and observing them in as many wavelengths as possible can be crucial to understanding the physics happening around the AGN’s black hole.
The key to recording as many wavelengths of light is not in the size of a single observatory, but the number of telescopes pointing at the AGN.
To organize such a communal effort, astronomers send an Astronomer’s Telegram, telling each other what’s happening in the night sky. This is particularly important for so-called time-domain astronomy, often focused on studying fast-changing phenomena, like AGN flares, sunspots, or supernovae. Thus, many small observatories can team up to help answer huge questions and provide inspiration and hands-on training to current and future researchers.
I am not the first to extol the virtues of small telescopes for big research. John Percy, former president of the Royal Astronomical Society of Canada, said in 1980: "There will always be a place at the forefront of astronomical research for yet another small telescope — amateur or professional — carefully and imaginatively used." Percy mentioned his fear of "the Beast" (the 74-inch optical telescope at the Dunlop Observatory outside Toronto) and his preference for smaller telescopes to investigate solar-system astronomy, stellar photometry, spectroscopy and other areas.
As our field and community continue to grow, it is more crucial than ever to root for the underdogs. While enormous technical marvels tend to get the most attention, there is much to be learned from thinking smaller. Many particle physicists, for example, are developing small-scale tabletop experiments that do not require a massive billion-dollar supercollider to perform — particularly during the inevitable period when the Large Hadron Collider (LHC) has been pushed to its limits and an even larger experiment is needed to probe higher-energy regimes.
As a young astronomer-to-be, I imagined working on the world's biggest telescopes to explore the universe's most far-away places. I have since done some of that, but I have also developed a profound appreciation for smaller-scale experimental technologies, like the kinds on which I started my career.
Even most sophisticated and powerful technologies will, one day, be outmoded by newer ones. But that does not negate the knowledge they allowed us to develop, nor the invaluable training and experience they afforded generations of emerging scientists.
It's natural that our attention tends to get drawn to the newest technologies with the greatest horsepower, but we shouldn't forget that the knowledge we can still gain from smaller, humbler experiments can be truly astronomical.
