“How big” is almost always an easier question to answer than
“how old.” Though we can measure the sizes of animals and plants
easily enough, we can often only guess at their ages. The same was
long true of the cosmos. The ancient Greeks Eratosthenes...
One of the most striking facts that we know about the cosmos is
that most of the chemical elements that constitute matter,
including our bodies, were produced inside stars and distributed
by their explosions. It is amazing how much we know about...
On the evening of November 11, 1572, twenty-six-year-old
astronomer Tycho Brahe was about to make a discovery that would
change his life and consequentially boost the scientific revolution
significantly. While casually staring at the night sky, he...
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...