May 4, 2024

South Pole Telescope Scientists Tell What It’s Like To Work at the Bottom of the Earth

Credit: NSF
Argonne physicists state cold, dry is best for taking a look at the earliest light in deep space.
It turns out the finest place on Earth to identify this light, understood as the cosmic microwave background, is the South Pole. The South Pole Telescope, a partnership amongst over 20 universities and nationwide laboratories including the University of Chicago and Argonne National Laboratory, started running in 2007.
Here, two physicists from Argonne National Laboratory speak about their deal with the South Pole Telescope and why it matters. Lindsey Bleem collects and examines data at the telescope, and Clarence Chang develops superconducting detectors for the telescope.

It turns out the best place on Earth to detect this light, understood as the cosmic microwave background, is the South Pole. The South Pole Telescope, a cooperation among over 20 universities and nationwide labs including the University of Chicago and Argonne National Laboratory, started running in 2007.
Just offering us this nice photograph, effectively, of the baby universe, the light that was given off at the time has been taking a trip the entire age of the universe, 14 billion years. Our telescope observes at millimeter wavelengths. Researchers who work at the South Pole Telescope measure the signal emitted by the earliest light in the universe (the cosmic microwave background).

The South Pole Telescope, a partnership amongst over 20 universities and nationwide labs including the University of Chicago and Argonne National Laboratory, maps the remaining light from the earliest age of the universe. Credit: Photo by Jason Gallicchio
What is the cosmic microwave background, and what does it tell us about deep space?
Chang: The cosmic microwave background is the signal that was produced when deep space was about 380,000 years old. It corresponds to a duration where deep space changed from this superhot plasma where electrons and protons were flying around to when, after deep space had cooled down far enough, protons and electrons could form atoms.
Today, that signal appears at the longer wavelengths, in the microwave range (a couple of millimeters). By looking and studying at the universe in those wavelengths, we can look at the early universe– basically, catch an infant picture.
The group of engineers and researchers working at the telescope throughout the 2011-12 season. Credit: Photo thanks to Nils Halverson
Bleem: Weve understood given that it was very first discovered in the 1960s that the CMB is extremely uniform. The variances in the temperature, which are tracing modifications in the density of this early plasma Clarence discussed, are just about one part in 100,000. We understand that these small variations had to grow over the entire age of the universe.
Besides just offering us this great photo, effectively, of the child universe, the light that was released at the time has been taking a trip the whole age of the universe, 14 billion years. It has actually interacted with all of the structures that have formed given that these early times. We can study the extremely subtle imprints that these structures make in the CMB to actually tease out the procedures and the physics that have occurred between when it was produced and today.
How do you do that?
Bleem: We do that through a couple of important, different clinical analyses. One is called gravitational lensing. This is where huge masses along the line of sight can really deflect the course of light.
The second is physics that happens when the photons– the light from the cosmic microwave background– can scatter off the material in these stepping in structures. We can trace this scattering procedure, and after that map out structures along the line of sight, which can assist us probe things like dark energy, which is greatly affecting the capability of really massive structures such as galaxy clusters to form.
Credit: NSF
And why does the telescope need to be at the South Pole?
This makes it a fantastic place for the astronomy we do at the South Pole Telescope. Our telescope observes at millimeter wavelengths. And it turns out that the South Pole is the outright best place on Earth to do this, followed by the Atacama Desert in Chile.
What is it like operating in that environment?
Chang: Were at the South Pole because it is dry. That dryness is great for our observations. As human beings, we like a little bit of humidity in the air. Thats something thats a bit difficult and can likewise disrupt how things go everyday.
Bleem: Yeah. Injuries dont recover extremely well at the South Pole. Its not great for computers to be in that dry environment.
Scientists who operate at the South Pole Telescope determine the signal emitted by the earliest light in the universe (the cosmic microwave background). The cold, dry air of Antarctica safeguards the signal from climatic interference. Credit: Photo courtesy of Lindsey Bleem
How does your work at Argonne connect to the telescope?
Chang: At Argonne we developed a superconducting technology for the detectors. These detectors have to determine photons that are relatively long in wavelength– normally a millimeter, 2 millimeters, 3 millimeters.
So we need to make a brand-new technology to do it. And at its core, that indicates understanding and managing superconducting materials and after that processing them to make these really sensitive detectors and to produce lots of them. At Argonne, there is a strong program in investigating fundamental products and in applying that to various innovations.
Bleem: We likewise combined our detector development really carefully to all the work thats being done utilizing the state-of-the-art supercomputers in the Argonne Leadership Computing Facility. We are hence able to make the crucial theoretical forecasts that allow us to connect the observations that we make with the South Pole Telescope to the forecasts from different cosmological designs about what we must be seeing.
So theres this really effective affiliation at Argonne, not just in between cosmologists and the product fabrication centers and the researchers there, however likewise with our fantastic computing experts.
The South Pole Telescope is moneyed and supported by the National Science Foundation, the DOE Office of High Energy Physics, the Kavli Institute for Cosmological Physics, the U.S. Antarctic Program and the Antarctic Support Contract.