cosmology

Scientists on the Dark Energy Survey have used observations of the smallest known galaxies to better understand dark matter, the mysterious substance that makes up 85% of the matter in the universe. The smallest galaxies can contain hundreds to thousands of times more dark matter than normal visible matter, making them ideal laboratories for studying this mysterious substance. By performing a rigorous census of small galaxies surrounding our Milky Way, scientists on the Dark Energy Survey have been able to constrain the fundamental particle physics that governs dark matter.

This 4-minute animation takes you on a flight that starts on Earth and travels one billion light years into space and back. It features data recorded by the Sloan Digital Sky Survey collaboration. Using the data recorded over the last 20 years, the SDSS collaboration has created the most detailed three-dimensional maps of the universe ever made, with deep multicolor images of one third of the sky, and spectra for more than three million astronomical objects.

Black holes are one of the most perplexing phenomena in the cosmos. There are many misconceptions in the popular press about their properties. In episode 15 of Subatomic Stories, Fermilab scientist Don Lincoln begins a several-episode miniseries talking about this fascinating phenomenon.

From New Scientist, July 15, 2020: Two sets of measurements to estimate the rate of expansion of the universe — described by the Hubble constant — conflict with one another, which may be a sign that our basic understanding of the cosmos is wrong. Two new attempts by astronomers to solve this problem have complicated things further. Fermilab scientist Antonella Palmese and her colleagues have used measurements of gravitational waves to calculate an independent value of the Hubble constant.

From Live Science, April 29, 2020: One of the deepest mysteries in physics could be explained by a long-since vanished form of dark matter. Fermilab scientist Dan Hooper is one of the authors of the new result. If an ancient form of dark matter decayed out of existence, that loss would have decreased the mass of the universe, which would have led to less gravity holding the universe together, which would have affected the speed at which the universe expands — helping explain the disagreement between measurements of the universe’s expansion.

With this six-minute video, Fermilab scientist Don Lincoln launches a special series called Subatomic Stories. You will learn a little bit about both the exciting subatomic world and the entire cosmos — and see how the two are inextricably linked. Each episode will focus on a specific topic, but the series will tell a much broader story.

From Five Books, March 30, 2020: Fermilab scientist Dan Hooper gives his recommendations for books on the Big Bang and talks about whether our entire understanding of the universe is about to be turned upside down.

Understanding how the universe began has been a goal for scientists, philosophers, and theologians for millennia. In this 14-minute video, Fermilab scientist Don Lincoln describes the scientific view on this topic. He covers what we know, what we think and what we may forever never know.