Polar program priorities, from penguins to primordial polarization patterns

Craig Hogan

Craig Hogan

Last week, a panel of experts convened by the National Academies of Science, Engineering and Medicine — specifically, the Polar Research Board’s Division on Earth and Life Studies — released a new report about top national science priorities for the next decade of Antarctic and Southern Ocean research. Two strategic priorities address urgent issues of planetary as well as polar significance: changes in sea levels and sea ice and adaptation of polar biota to a changing environment. The third priority looks beyond the end of the planet, to the edge of space and time: The report recommends a “next-generation cosmic microwave background program” to address the question, “How did the universe begin, and what are the underlying physical laws that govern its evolution and ultimate fate?”

The report shows that our partners at the pole share our excitement about cosmology. The pattern of intensity and polarization in the cosmic microwave background — the light from the Big Bang that still fills the universe today — is one of the most powerful and precise probes of how physics behaves at its largest scales, emptiest spaces and earliest times. The South Pole is one of the best places on Earth for viewing and mapping it: very cold, very high and very dry.

The more sky we survey, the better the precision, and the higher the angular resolution, the more information about the universe we can extract from the maps. In the next-generation program, DOE labs will enable enormous upgrades in the scale of instrumentation, such as detectors and cameras. Right now, a new camera is coming together at Fermilab, on its way to the South Pole next year, with an order of magnitude more detectors than its predecessor. The next-generation program could increase survey speed even beyond that, by up to a factor of 30 or more.

The new instruments will lead to advances in many fundamental physical measurements, addressing deep mysteries such as the acceleration of the cosmic expansion. They will even reveal properties of our favorite Fermilab subject, neutrinos: Primordial neutrinos are a billion times more common than other matter particles in the universe as a whole, so even their tiny masses make a difference in shaping the largest-scale cosmic structures.

Our polar-minded colleagues do us a great service by counting cosmic background studies among their highest scientific priorities. Their holistic view of science reminds us of John Muir’s adage that “when we try to pick out anything by itself, we find it hitched to everything else in the Universe.” The South Pole is a good place to connect from the surface of the Earth to the beginning of time.

Craig Hogan is the head of the Center for Particle Astrophysics.