This interview was originally broadcast on January 24, 2011. The Hidden Reality: Parallel Universes and the Deep Laws Of the Cosmos is now available in paperback. Greene is also hosting a NOVA series based on his book The Fabric of the Cosmos.

Our universe might be really, really big — but finite. Or it might be infinitely big.

Weekend Edition Sunday host Audie Cornish will be filling in for Michele Norris on All Things Considered for a year, starting in January, NPR just announced.

Good morning.

Our early headlines:

-- WikiLeaks' Julian Assange Loses Extradition Appeal.

-- Lawyer: One Of Cain's Accusers Wants Her Story Told.

-- Crisis Talks In Cannes Over Greek Bailout Plan.

The Paris offices of a French newsweekly that in its latest issue "invited" the Prophet Muhammad to be a guest editor and satirically wrote of what a "soft version" of Sharia law might be like, were burned early today.

According to The Associated Press:

After a bad day Tuesday, financial markets are faring better so far today.

The lawyer for one of two women who in the late 1990s accused Republican presidential contender Herman Cain of sexual harassment wants her side of the story to come out because she believes Cain has not been telling the truth about what happened, a lawyer who represents her said Tuesday on CNN's Anderson Cooper 360.

British judges ruled this morning that WikiLeaks founder Julian Assange can be extradited from the U.K. to Sweden, where authorities want to question him about allegations from two women that he sexually assaulted them in August 2010.

Police are on the hunt for the bandits who robbed a Union Pacific Railroad car after it made an emergency stop in Victorville, Calif. They made off with 20 boxes. Police told the Victorville Daily Press that the robbers couldn't have known what was in the car; they made off with $200 worth of pigs feet.

The pro basketball season still hasn't started, but Kevin Durant got a workout. The Oklahoma City star drove across the state to a flag football game. On Twitter the other night, he wrote, "This lockout is really boring. Anybody playing flag football?" An Oklahoma State student invited Durant to join a game his team had planned.

Right now, many people are nervous about the challenges presented by a global population that has reached 7 billion and is still rising. But for a lot of countries, a lack of babies is the bigger worry.

The so-called birth dearth is starting to cause problems across much of Europe and a substantial portion of Asia. With fewer children born, populations in many countries are aging rapidly. Soon, they may also be shrinking.