The field of cosmology has come a long way toward understanding
the universe as a physical system: we’ve mapped its history and
structure in great detail, we know what it went through since a few
seconds after its birth until today, we understand...
Five years ago, NASA’s Fermi Gamma-ray Space Telescope saw more
gamma rays than expected from the area around the center of our
galaxy. Many scientists suggest that the extra gamma rays could be
from the annihilation of dark matter particles. This...
In 1913, Victor Hess measured the background level of
atmospheric ionization while ascending with a balloon. By doing so,
he discovered that Earth is continuously bathed in ionizing
radiation. These cosmic rays primarily consist of protons
The theoretical astrophysicist and Princeton University
professor is well known for his work on NASA’s 2001 Microwave
Anisotropy Probe—he conceptualized the mission and deciphered the
radio telescope’s data to measure the age of the universe,
In the public lecture “The Latest News from the Cosmos,” Matias
Zaldarriaga, Professor in the School of Natural Sciences, explores
the most detailed map of the infant universe to date. Publicly
released on March 21, 2013, the map shows relic...
Following the discovery in July of a Higgs-like boson—an effort
that took more than fifty years of experimental work and more than
10,000 scientists and engineers working on the Large Hadron
Collider—Juan Maldacena and Nima Arkani-Hamed, two...
Why is the expansion of the universe speeding up, instead of
being slowed by the gravitational attraction of galaxies and dark
matter? What is the history of the Milky Way galaxy and of the
chemical elements in its stars? Why are the planetary...
For slightly over a year, I have largely put aside my longtime
interests in the foundations of quantum mechanics and in particle
physics, and have been working on dark matter. This interest came
about in two different ways. The first was a paper on...
One of the remarkable discoveries in astrophysics has been the
recognition that the material we see and are familiar with, which
makes up the earth, the sun, the stars, and everyday objects, such
as a table, is only a small fraction of all of the...
In the public lecture “The World’s Largest Experiment,” Nathan
Seiberg, Professor in the School of Natural Sciences, discusses the
Large Hadron Collider (LHC) and the potential discoveries it may
yield—among them, new insights about the origin of...