Heart of Darkness: Understanding the Invisible Universe of Dark Matter and Dark Energy

Jeremiah P. Ostriker
Charles A. Young Professor Emeritus, Astrophysical Sciences Dept., Princeton University

Videography by Nerine & Robert Clemenzi, Edited by Nerine Clemenzi
Copyright © Philosophical Society of Washington.  All rights reserved.


The on-going quest to construct a scientific model of the universe has been an extraordinary saga of observation, engineering, theoretical exploration, and hypothesis testing. It has culminated in the understanding, developed over the past three decades, that the known universe is almost entirely (96%) composed of dark matter and dark energy. The first, dark matter, gravitationally accelerates the formation of cosmic structures. The second, dark energy, pushes these structures apart after they form. Considered together, these two components, little understood and never directly observed, can explain the growth of all cosmic structure and the dynamics that are the key to the universe's fate.

This lecture will explore the history and the physics of our current model of the universe: How did structure in the universe arise, how has it evolved, and what is its ultimate fate? The lecture will emphasize the role of three critical aspects of rational scientific inquiry in arriving at the current cosmological paradigm: The application of direct measurement and observation, the use of rigorous mathematical modeling, and the requirement that hypotheses be testable and verifiable. And, while pointing out how the current paradigm has met critical analysis thus far and "works" to great precision, the lecture will also discuss some fundamental questions about the cosmos that the current model does not answer.

About the Author:

Jeremiah Ostriker

Jeremiah P. Ostriker is the Charles A. Young Professor Emeritus of Astrophysical Sciences at Princeton University, a member of the Dept. of Astronomy and Astrophysics at Columbia, and Treasurer of the National Academy of Sciences. Previously he served as Provost of Princeton University.

He has carried out seminal research in many areas of theoretical astrophysics and cosmology, including work on gravitational lensing, rotating stars, pulsars, X-ray binaries, the evolution of star systems, such as globular clusters, galaxy formation, the stability of galaxies, active galactic nuclei, astrophysical blast waves, the dynamics of galaxy clusters, and the cosmic web. He was instrumental, with James Gunn and others, in planning, funding, and building the Sloan Digital Sky Survey facility and carrying out the survey. He also played a significant part in the work that led to the discovery that dark matter and dark energy are fundamental constituents of the universe. Currently he is working to better understand the formation and evolution of galaxies and their central black holes.

Among many awards, he is the recipient of the Henry Norris Russell Prize of the American Astronomical Society, the Vainu Bappu Memorial Award of the Indian National Science Academy, the Karl Schwarzschild Medal of the German Astronomische Gesellschaft, the Royal Astronomical Society Gold Medal, the National Medal of Science (awarded by President Clinton), and, recently, he was recognized by President Obama as a Champion of Change for his work on the Sloan Digital Sky Survey.

Jerry has supervised and collaborated with many young researchers and graduate students. He is an author on more than 500 scientific publications and he is co-author, with Simon Mitton, of Heart of Darkness: Unraveling the Mysteries of the Invisible Universe, intended for general audiences and recently published by Princeton University Press.

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