building

The use of concrete dates back to ancient Rome, and the recipe hasn't changed much since then. Neither have some of concrete's drawbacks. In particular, the slow deformation known as "concrete creep" has afflicted structures from the Pantheon to the Pentagon. But MIT scientists believe they have solved the mystery of concrete creep, and thus opened the door to structures that will last tens of thousands of years.

Name: Oasis of the Seas
Where: Florida
Cost: $1.2 billion
Estimated Completion: This year
The Challenge: Build an 18-story-tall superliner with more outdoor space

When the Oasis of the Seas sets sail later this year, it will claim the record for biggest passenger ship, with space for 6,300 passengers, 2,000 more than any other ship. But it will also claim the most rooms with balconies, the biggest onboard swimming pool, and the first at-sea, tree-filled, outdoor park.

Name: Perdido Spar
Where: Gulf of Mexico
Cost: Undisclosed
Estimated Completion: First oil, 2010; all wells online, 2016
The Challenge: Moor a skyscraper-size floating rig to the seafloor, then drill the world's deepest subsea well

Two hundred miles off the coast of Galveston, Texas, below 10,000 feet of water and another 9,000 feet of mud, salt and rock, lies Shell Oil's most ambitious new target, a swath of seabed the size of Houston that holds enough oil and natural gas to produce up to 130,000 barrels a day.