Online Price: $7.95 Click here to order a print copy. $10.95 US and $13.95 elsewhere.

Things get weird-spectacularly so-at the borderlands of physics. The rarefied realms described mathematically and sometimes glimpsed in experiments are all the more extraordinary for not being the mere products of someone's hyperactive imagination.

For instance, string theory's equations imply that the universe contains six extra dimensions, which are too tiny to have yet been detected. Some physicists also see innumerable theoretical universes in their equations. And although we perceive space and time as being continuous, quantum principles imply that, in fact, at the very smallest scales they actually come in pieces. The effects of this discrete structure could be revealed in experiments in the near future.

Intellectual enrichment aside, it might be tempting to think that none of what scientists are learning by probing the frontiers of physics truly matters in our everyday lives. Not so. As just one example, consider general relativity, which explains how gravity results from bends in the fabric of spacetime itself. To be accurate, commonplace GPS receivers-which calculate location using a constellation of orbiting satellites-must take the effects of general relativity into account.

In the pages of this special edition, we invite you to take an armchair journey through our curious universe, with our scientist authors as tour guides. You're in for a mind-boggling treat. -The Editors

Rethinking the Basic Laws of Nature

The Dawn of Physics beyond the Standard Model by Gordon Kane
The Standard Model of particle physics is at a pivotal moment in its history: it is both at the height of its success and on the verge of being surpassed.

The Search for Relativity Violations by Alan Kostelecky
To uncover evidence for an ultimate theory, scientists are looking for infractions of Einstein's once sacrosanct physical principle.

Solving the Solar Neutrino Problem by Arthur B. McDonald, Joshua R. Klein and David L. Wark
The Sudbury Neutrino Observatory has solved a 30-year-old mystery by showing that neutrinos from the sun change species en route to the earth.

The Mysteries of Mass by Gordon Kane
Physicists are hunting for an elusive particle that would reveal the presence of a new kind of field that permeates all of reality. Finding that Higgs field will give us a more complete understanding about how the universe works.

Tying Together the Universe with Strings and Loops

The String Theory Landscape by Raphael Bousso and Joseph Polchinski
The theory of strings predicts that the universe might occupy one random "valley" out of a virtually infinite selection of valleys in a vast landscape of possibilities.

The Future of String Theory: A Conversation with Brian Greene by George Musser
The physicist and best-selling author demystifies the ultimate theories of space and time, the nature of genius, multiple universes, and more.

Atoms of Space and Time by Lee Smolin
We perceive space and time to be continuous, but if the amazing theory of loop quantum gravity is correct, they actually come in discrete pieces.

Insights into an Old Constant, a New Hologram and Time

A Cosmic Conundrum by Lawrence M. Krauss and Michael S. Turner
A new incarnation of Einstein's cosmological constant may point the way beyond general relativity.

Information in the Holographic Universe by Jacob D. Bekenstein
Theoretical results about black holes suggest that the universe could be like a gigantic hologram.

That Mysterious Flow by Paul Davies
From the fixed past to the tangible present to the undecided future, it feels as though time flows inexorably on. But that is an illusion.