Edge of the Universe
A Voyage to the Cosmic Horizon and Beyond

By Paul Halpern

Cover of "Collider"

Cosmology, the science of the universe, is undergoing a startling revolution!

Colossal flows of galaxies, large empty regions called voids, and other unexplained phenomena offer clues that our own "bubble universe" could be part of a greater realm called the multiverse.

How big is the observable universe? What it is made of? What lies beyond it?

Was there a time before the Big Bang? Could space have unseen dimensions?

What exactly is the "axis of evil?" And what are the mysterious cosmic dragons that lurk in the gamma ray fog?

Edge of the Universe investigates these fascinating questions and more, offering the background behind humanity's search for the frontiers of the universe!

Praise for Edge of the Universe

  • A fantastic romp along the frontiers of modern cosmology – and beyond. Halpern makes us wonder about our place in the vast universe, both in space and time, and marvel at the mystery of dark matter, dark energy, extra dimensions, parallel universes, and so much more.
    —Cliff Pickover, author of The Physics Book: From the Big Bang to Quantum Resurrection
  • In this lively, fast-paced and authoritative book, Paul Halpern takes us not only to the edge of the universe but to the edge of our knowledge of the universe.
    —Marcus Chown, author of Solar System: A Visual Exploration of All the Planets, Moons and Other Heavenly Bodies that Orbit Our Sun
  • A delightful introduction to all the major topics in modern cosmology. In user-friendly language, Halpern manages to describe the ins and outs of this complex subject, from the well-established to the highly speculative. This is truly a remarkable accomplishment.
    —Gino Segre, author of Faust in Copenhagen: A Struggle for the Soul of Physics
  • Cosmology today is more exciting than it has ever been in its 2500-year history. In this lively book, Halpern explains why and leaves us desperate to see what surprises the universe has in store..
    —Graham Farmelo, author of The Strangest Man: The Hidden Life of Paul Dirac, Mystic of the Atom
  • Edge of the Universe is a breezy romp through the universe as we know it.  Paul Halpern covers all of the big topics in cosmology with a crisp and engaging tone, at a level that even a novice can follow, and pairs it with pop cultural references and very engaging scientific history. He gives a grand view of not only what we know, but also what we don’t entirely understand from inflation and the edge of the Universe to the “Axis of Evil” in the cosmic microwave background and the dark flow of galaxies.
    —Dave Goldberg, io9.com contributor and author of A User’s Guide to the Universe

About Edge of the Universe

These are extraordinary times for humanity's quest to understand the universe.  Cosmology has entered an age of unprecedented precision.  Long sought questions such as the age and shape of the universe have finally been resolved.  We now know that the time since the Big Bang is 13.75 billion years.  In contrast to earlier views that space could be curved or saddle-shaped, we now know that it is as flat as a pancake. 

Yet, despite these tremendous advances, science has come to realize that much of the universe is made of unknown substances and influences.  More than 95 percent of the universe is made of dark energy and dark matter, with less than 5 percent constituting the familiar stuff of atoms, molecules, people, and planets.  Dark energy makes itself felt through its unseen influence on galaxies, causing them to move away from each other at a faster and faster pace.  Dark matter, on the other hand, steers the outer stars of galaxies, binding them to galactic cores.  It also supplies the gravitational "glue" needed to keep clusters of galaxies intact.  Experiments have failed so far to reveal the true nature of these mysterious entities.

These are far from the only cosmological enigmas.  A strange dark flow seems to be driving galaxy clusters toward an unknown destination.   Scientists wonder if it could be a sign of tugs from regions beyond the observable universe.  Indeed the theory of inflation, the leading explanation for why the observable is relatively uniform, offers the intriguing possibility that our universe is a mere drop in a vast cosmic sea called the multiverse.  Researchers are examining the cosmic microwave background searching for signs of collisions with other universes.

The cosmic microwave background offers ample conundrums.  A strange alignment, called the "axis of evil," has perplexed astronomers.  While other oddities, such as Stephen Hawking's initials displayed in the radio sky, can be explained by coincidence, could the "axis of evil" represent a preferred direction in the cosmos?  Cosmic dragons, unidentified sources lurking in the gamma-ray fog, offer another intriguing puzzle. 

Is time travel possible?  Does the universe have unseen extra dimensions?  Could an advanced civilization construct traversible wormholes to expedite interstellar travel?  What is the fate of the universe?  Could there have been cycles of time before the Big Bang?

Edge of the Universe:  A Voyage to the Cosmic Horizon and Beyond explores these strange mysteries and more.  It offers a passport to the frontiers of contemporary cosmology, examining the latest discoveries and debates in the scientific quest to unravel the mysteries of the universe.


Contents: Edge of the Universe

Prologue: Cosmology’s Extraordinary New Frontiers

1. How Far Out Can We See? Voyage to the Edge of the Known Universe

2. How Was the Universe Born? Revealing the Dawn of Time

3. How Far Away Will the Edge Get? The Discovery of the Accelerating Universe

4. What Is Dark Energy? Will It Tear Space Apart?

5. Do We Live in a Hologram? Exploring the Boundaries of Information

6. Why Does the Universe Seem so Smooth? The Inflationary Era

7. Are There Alternatives to Inflation? Extra Dimensions and the Big Bounce

8. What Builds Structure in the Universe? The Search for Dark Matter

9. What is Tugging on Galaxies? The Mysteries of Dark Flow and the Great Attractor

10. What Are the Axis of Evil and Other Strange Features of the Cosmic Background?

11. What Are the Immense Blasts of Energy From the Farthest Reaches of Space? Gamma-Ray Bursts and the Quest for Cosmic Dragons

12. Can We Journey to Parallel Universes? Wormholes as Gateways

13. Is the Universe Constantly Splitting into Multiple Realities? The Many Worlds Hypothesis

14. How Will the Universe End? Out With a Bang, Bounce, Crunch, Rip, Stretch, or Whimper

15. What Are the Ultimate Limits of Our Knowledge About the Cosmos?


About the Author

Paul Halpern is a professor of physics at the University of the Sciences in Philadelphia. He is the author of more than a dozen highly acclaimed popular science books, is the distinguished recipient of multiple awards related to his work, and has appeared on numerous television and radio programs, including Future Quest and The Simpsons 20th Anniversary Special. Learn more about him on his personal website.