Space & PhysicsJune 1, 2018
What Is Dark Matter?
An elusive substance that permeates the universe exerts many detectable gravitational influences yet eludes direct detection
Stories by Lisa Randall
Lisa Randall is Frank B. Baird, Jr., Professor of Science at Harvard University. She serves on Scientific American's board of advisers. Among her many books is Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe (2015).
The SciencesSeptember 22, 2011
Ghosts, Aliens, Quantum Gravity, Extra Dimensions, Sci Fi--and the Rules of Science
In this excerpt from the new book Knocking on Heaven's Door: How Physics and Scientific Thinking Illuminate the Universe and the Modern World (Harper Collins, 2011), you'll learn why, although it's true that scientists sometimes have been wrong, that doesn't mean there are no rules--or that everything is possible